WorldWideScience

Sample records for electron accelerator worldwide

  1. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  2. Application of electron accelerator worldwide

    International Nuclear Information System (INIS)

    Machi, Sueo

    2003-01-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  3. High brightness electron accelerator

    International Nuclear Information System (INIS)

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

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of accelerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electrons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electrons as the electrons enter the first cavity. 5 figs

  4. The auroral electron accelerator

    International Nuclear Information System (INIS)

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

    1989-01-01

    A model of the auroral electron acceleration process is presented in which the electrons are accelerated resonantly by lower-hybrid waves. The essentially stochastic acceleration process is approximated for the purposes of computation by a deterministic model involving an empirically derived energy transfer function. The empirical function, which is consistent with all that is known of electron energization by lower-hybrid waves, allows many, possibly all, observed features of the electron distribution to be reproduced. It is suggested that the process occurs widely in both space and laboratory plasmas. (author)

  5. 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)

  6. Climate change accelerates growth of urban trees in metropolises worldwide.

    Science.gov (United States)

    Pretzsch, Hans; Biber, Peter; Uhl, Enno; Dahlhausen, Jens; Schütze, Gerhard; Perkins, Diana; Rötzer, Thomas; Caldentey, Juan; Koike, Takayoshi; Con, Tran van; Chavanne, Aurélia; Toit, Ben du; Foster, Keith; Lefer, Barry

    2017-11-13

    Despite the importance of urban trees, their growth reaction to climate change and to the urban heat island effect has not yet been investigated with an international scope. While we are well informed about forest growth under recent conditions, it is unclear if this knowledge can be simply transferred to urban environments. Based on tree ring analyses in ten metropolises worldwide, we show that, in general, urban trees have undergone accelerated growth since the 1960s. In addition, urban trees tend to grow more quickly than their counterparts in the rural surroundings. However, our analysis shows that climate change seems to enhance the growth of rural trees more than that of urban trees. The benefits of growing in an urban environment seem to outweigh known negative effects, however, accelerated growth may also mean more rapid ageing and shortened lifetime. Thus, city planners should adapt to the changed dynamics in order to secure the ecosystem services provided by urban trees.

  7. 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

  8. VEBA relativistic electron accelerator

    International Nuclear Information System (INIS)

    Parker, R.K.; Ury, M.

    1975-01-01

    The VEBA high-current, relativistic electron accelerator was designed and constructed at NRL for applications in the study of high-power microwave sources. To meet the requirements of this study, the accelerator was designed for operation in either a short (60 nsec) or long (2.2 μsec) pulse mode. The short-pulse mode has been in operation for nearly two years and has proven to be an extremely reliable design. The design of the long-pulse mode is now complete and component fabrication will soon be underway. The pulse-forming network in the short-pulse mode is an unbalanced, water Blumlein with an output impedance of 9.2 Ω. The Blumlein is pulse charged by a 17 stage Marx generator which has a series capacitance of 29.4 nF. By transmission along a tapered coaxial line, the output pulse is transformed to 20 Ω, and the voltage developed across a matched load increases to a maximum of 2.3 MV. The proposed conversion to the long-pulse mode will require the Blumlein and transformer sections be removed and the diode assembly be attached directly to the oversized Marx tank. The direct coupling between the Marx and the Blumlein will then be replaced by two nested water capacitors, which are shunted by spiral inductors. When coupled in series with the Marx, this output filter will form a three-section, voltage-fed, Guillemin (type A), pulse-forming network with a characteristic impedance of 40 Ω and a maximum output voltage of 0.9 MV. (auth)

  9. Electronic pre-publishing for worldwide access

    International Nuclear Information System (INIS)

    Dallman, D.; Draper, M.; Schwarz, S.

    1994-01-01

    In High Energy Physics, as in other areas of research, paper preprints have traditionally been the primary method of communication, before publishing in a journal. Electronic bulletin boards (EBBs) are now taking over as the dominant medium. While fast and readily available EBBs do not constitute electronic journals as they bypass the referee system crucial for prestigious research journals, although this too may be achieved electronically in time. (UK)

  10. 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

  11. Guassian beams and electron acceleration

    International Nuclear Information System (INIS)

    Collins, M.; Castillo, R.; Osman, F.; Evans, P.; Stiat-Gardener, T.; Hora, H.

    2000-01-01

    Full text: A guassian solution to the free space wave equation to fourth order is derived using the Fourier transform method. Higher order solutions can be generated, as needed, using the convolution method. These results are used to investigate the acceleration of an electron in a laser field. The acceleration is determined if energy is transferred to a relativistic electron, this energy transfer can be determined by calculating the change in the potential of the electron

  12. Electron accelerators for radiation sterilization

    International Nuclear Information System (INIS)

    Zimek, Z.; Stanikowski, J.

    2007-01-01

    Presentation describes briefly different types of the electron accelerators applicable for the radiosterilization of food and/or medical materials. LAE 10 source operating in the Institute of Nuclear Chemistry and Technology (Warsaw, Poland) is described in details

  13. 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

  14. 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

  15. 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)

  16. 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...

  17. 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.

  18. Low voltage electron beam accelerators

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-02-01

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

  19. 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)

  20. 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.

  1. 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

  2. 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

  3. High-current electron accelerator

    Science.gov (United States)

    Alekseyev, B. V.; Gorelikov, I. M.; Kazurov, V. I.; Mashkov, L. V.; Greshko, A. G.; Soklakov, G. I.; Fedorenko, A. I.; Yurekevich, K. B.

    1986-02-01

    A high current electron accelerator was developed and built on the basis of computer aided design calculations and electrolytic trough simulation. A 15 stage Arkadyev/Marx pulse voltage generator serves as the primary energy storing device. Each stage consists of two IK-100-0.4 capacitors connected in parallel and all immersed in transformer oil inside a metal container on electrically insulating posts. Each stage is shielded on both the positive and negative potential side. The shields, made of copper foil, not only smooth the electric field in the clearances but also constitute part of the commutating circuit and contribute to reduction of the overall generator size. The pulse voltage generator is triggered by a synchronizer through the conventional firing circuit of a TGI1-350/16 thyratron. To operate the accelerator in the nanosecond mode, the generator discharges into a diode through a twin shaping line. In this mode the accelerator can produce 0.8 MeV to 240 kA electron beams of 0.8 ns duration. To operate in the microsecond mode, the shaping line acts as storing capacitor, and the discharge gaps must be charged with polarity reversal in each stage. In this mode the accelerator can produce 0.5 MeV to 10 kA electron beams of 1 microsecond duration.

  4. Electron Cloud Effects in Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Furman, M.A.

    2012-11-30

    Abstract 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 [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

  5. 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)

  6. 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.)

  7. 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...... such as graphite and aluminium have been used. These materials offer advantages of simpler construction and higher sensitivity. Dose estimates using these different types of calorimeters differ by ~5%, and the possible reasons for these discrepancies are discussed...

  8. 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)

  9. 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

  10. Electron accelerators and nanomaterials - a symbiosis

    International Nuclear Information System (INIS)

    Dixit, Kavita P.; Mittal, K.C.

    2011-01-01

    Electron Accelerators and Nanomaterials share a symbiotic relationship. While electron accelerators are fast emerging as popular tools in the field of nanomaterials, use of nanomaterials so developed for sub-systems of accelerators is being explored. Material damage studies, surface modification and lithography in the nanometre scale are some of the areas in which electron accelerators are being extensively used. New methods to characterize the structure of nanoparticles use intense X-ray sources, generated from electron accelerators. Enhancement of field emission properties of carbon nanotubes using electron accelerators is another important area that is being investigated. Research on nanomaterials for use in the field of accelerators is still in the laboratory stage. Yet, new trends and emerging technologies can effectively produce materials which can be of significant use in accelerators. Properties such as enhanced field emission can be put to use in cathodes of electron guns. Superconducting properties some materials may also be useful in accelerators. This paper focusses on the electron accelerators used for synthesis, characterization and property-enhancement of nanomaterials. The details of electron accelerators used for these applications will be highlighted. Some light will be thrown on properties of nano materials which can have potential use in accelerators. (author)

  11. 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.

  12. Survey of high voltage electron microscopy worldwide in 1998.

    Energy Technology Data Exchange (ETDEWEB)

    Allen, C. W.

    1998-03-05

    High voltage TEMs were introduced commercially thirty years ago, with the installations of 500 kV Hitachi instruments at the Universities of Nagoya and Tokyo. Since that time 53 commercial instruments, having maximum accelerating potentials of 0.5-3.5 MV, will have been delivered by the end of 1998. Table 1 summarizes the sites and some information regarding those HVEMS which are available in 1998. This corrects, updates and expands an earlier report of this sort [2]. There have been three commercial HVEM manufacturers: AEI (UK), Hitachi and JEOL (Japan). The proportion of the total number of HVEMS produced by each manufacturer is similar to that reflected in Table 1: AEI and Kratos/AEI (12), Hitachi (20) and JEOL (21). The term Kratos/AEI refers to instruments delivered after the takeover of AEI by Grates in the late 1970's. In Table 1 only maximum accelerating potentials are listed, which is generally also the design value for which the resolution for imaging was optimized. It is important to realize that in many applications, especially those studying irradiation effects, much lower voltages may be employed somewhat routinely to minimize atom displacements by the incident electron beam during analysis. These minimum values range from 100 kV for the AEI and Kratos/AEI instruments to typically 400 kV for the current generation of atomic resolution instruments, the latter being well above the thresholds for displacement in light elements such as Al and Si and for displacement of anions in many ceramic materials such as the high Tc superconductors, for example. An additional potential problem is electron-induced sputtering and differential sputtering (unequal sputtering rates in multicomponent materials), especially when accurate elemental microanalysis is being attempted. These same issues may arise for intermediate voltage TEMs as well, of course.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. Two theories of auroral electron acceleration

    International Nuclear Information System (INIS)

    Bryant, D.A.

    1990-03-01

    Two theories of auroral electron acceleration are discussed. The first is 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. The second is 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)

  18. Accelerators in industrial electron beam processing

    International Nuclear Information System (INIS)

    Becker, R.C.

    1984-01-01

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

  19. Double Relativistic Electron Accelerating Mirror

    Directory of Open Access Journals (Sweden)

    Saltanat Sadykova

    2013-02-01

    Full Text Available In the present paper, the possibility of generation of thin dense relativistic electron layers is shown using the analytical and numerical modeling of laser pulse interaction with ultra-thin layers. It was shown that the maximum electron energy can be gained by optimal tuning between the target width, intensity and laser pulse duration. The optimal parameters were obtained from a self-consistent system of Maxwell equations and the equation of motion of electron layer. For thin relativistic electron layers, the gaining of maximum electron energies requires a second additional overdense plasma layer, thus cutting the laser radiation off the plasma screen at the instant of gaining the maximum energy (DREAM-schema.

  20. 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

  1. Electron accelerator Ridgetron for industrial irradiation

    International Nuclear Information System (INIS)

    Hattori, Toshiyuki; Hayashizaki, Noriyosu; Odera, Masatoshi

    1999-01-01

    A compact RF electron accelerator, the Ridgetron, with a ridged cavity resonator has been developed for industrial irradiation. It is of a recirculating acceleration type and is intended to have an energy range of 0.5 - 10 MeV and a beam power of 1-25 kW. A prototype system with an energy of 2.5 MeV and a beam power of 6.5 kW was constructed to confirm the feasibility. Acceleration test is doing now. (author)

  2. 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.)

  3. 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

  4. 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

  5. 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.

  6. 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)

  7. Beam profile for Malaysian electron accelerator

    International Nuclear Information System (INIS)

    Abu Bakar Ghazali; Muhamad Zahidee Taat

    2007-01-01

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

  8. 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)

  9. Electron acceleration during streamer collisions in air

    DEFF Research Database (Denmark)

    Köhn, Christoph; Chanrion, Olivier; Neubert, Torsten

    2017-01-01

    High-voltage laboratory experiments show that discharges in air, generated over a gap of one meter with maximal voltage of 1 MV, may produce X-rays with photon energies up to 1 MeV. It has been suggested that the photons are bremsstrahlung from electrons accelerated by the impulsive, enhanced field...... during collisions of negative and a positive streamers. To explore this process, we have conducted the first self-consistent particle simulations of streamer encounters. Our simulation model is a 2-D, cylindrically symmetric, particle-in-cell code tracing the electron dynamics and solving the space...

  10. Electron clouds in high energy hadron accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Fedor

    2013-08-29

    The formation of electron clouds in accelerators operating with positrons and positively charge ions is a well-known problem. Depending on the parameters of the beam the electron cloud manifests itself differently. In this thesis the electron cloud phenomenon is studied for the CERN Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC) conditions, and for the heavy-ion synchrotron SIS-100 as a part of the FAIR complex in Darmstadt, Germany. Under the FAIR conditions the extensive use of slow extraction will be made. After the acceleration the beam will be debunched and continuously extracted to the experimental area. During this process, residual gas electrons can accumulate in the electric field of the beam. If this accumulation is not prevented, then at some point the beam can become unstable. Under the SPS and LHC conditions the beam is always bunched. The accumulation of electron cloud happens due to secondary electron emission. At the time when this thesis was being written the electron cloud was known to limit the maximum intensity of the two machines. During the operation with 25 ns bunch spacing, the electron cloud was causing significant beam quality deterioration. At moderate intensities below the instability threshold the electron cloud was responsible for the bunch energy loss. In the framework of this thesis it was found that the instability thresholds of the coasting beams with similar space charge tune shifts, emittances and energies are identical. First of their kind simulations of the effect of Coulomb collisions on electron cloud density in coasting beams were performed. It was found that for any hadron coasting beam one can choose vacuum conditions that will limit the accumulation of the electron cloud below the instability threshold. We call such conditions the ''good'' vacuum regime. In application to SIS-100 the design pressure 10{sup -12} mbar corresponds to the good vacuum regime. The transition to the bad vacuum

  11. Use of electron accelerators in food irradiation

    International Nuclear Information System (INIS)

    Sanyal, Bhaskar

    2013-01-01

    Preservation of food by ionizing radiations involves controlled application of energy of radiation to agricultural commodities, foods and food ingredients, for improving storage life, hygiene and safety. Insects and microbes cause major economic losses to stored crops. Many of our food products are contaminated with diseases causing germs and toxin producing molds. Without improvement in microbial quality and getting properly treated to overcome quarantine barriers our agricultural products cannot get international markets. In this respect electron accelerators have immense potential in commercial radiation processing of foods. Both low and high dose applications with increased process rates can be achieved using accelerators to cover a wide spectrum of food commodities approved for commercial radiation processing as per the recent gazette notification under Atomic Energy (Radiation Processing of Food and Allied Products) Rule, 2012. The effectiveness of processing of food by ionizing radiation depends on proper delivery of absorbed dose and its reliable measurement. For food destined for international trade, it is important that the dosimetry used for dose determination is carried out accurately and that the process is monitored in accordance with the internationally accepted procedures. Experiments using alanine-EPR system were carried out to optimize the process parameters of 10 MeV electron beam for commercial irradiation of food. Different food commodities namely, mango, potato and rawa (semolina) were irradiated to measure the absorbed dose distribution. The actual depth dose profile in food products and useful scan width of the electron beam were determined for commercial radiation processing of food using electron beam. (author)

  12. Therapeutic dose from a pyroelectric electron accelerator.

    Science.gov (United States)

    Fullem, T Z; Fazel, K C; Geuther, J A; Danon, Y

    2009-11-01

    Simple heating of pyroelectric crystals has been used as the basis for compact sources of X rays, electrons, ions and neutrons. We report on the evaluation of the feasibility of using a portable pyroelectric electron accelerator to deliver a therapeutic dose to tissue. Such a device could be mass produced as a handheld, battery-powered instrument. Experiments were conducted with several crystal sizes in which the crystal was heated inside a vacuum chamber and the emitted electrons were allowed to penetrate a thin beryllium window into the surrounding air. A Faraday cup was used to count the number of electrons that exited the window. The energy of these electrons was determined by measuring the energy spectrum of the X rays that resulted from the electron interactions with the Faraday cup. Based on these measurements, the dose that this source could deliver to tissue was calculated using Monte Carlo calculations. It was found that 10(13) electrons with a peak energy of the order of 100 keV were emitted from the beryllium window and could deliver a dose of 1664 Gy to a 2-cm-diameter, 110-microm-deep region of tissue located 1.5 cm from the window with air between the window and the tissue. This dose level is high enough to consider this technology for medical applications in which shallow energy deposition is beneficial.

  13. 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)

  14. 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)

  15. 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)

  16. 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)

  17. 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.

  18. Environmental assessment: Continuous Electron Beam Accelerator Facility, Newport News, Virginia

    International Nuclear Information System (INIS)

    1987-01-01

    This Environmental Assessment has been prepared by the US Department of Energy (DOE) to fulfill its obligations pursuant to Sect. 102 of the National Environmental Policy Act (NEPA) of 1969 (Public Law 91-190). The proposed federal action addressed in this document is DOE's funding of a Continuous Electron Beam Accelerator Facility (CEBAF) at Newport News, Virginia. DOE intends to contract with the Southeastern Universities Research Association (SURA) for operation of CEBAF, a continuous wave (CW) linear accelerator system (linac) capable of providing high-duty-factor beams throughout the energy range from 0.5 to 4.0 GeV. CEBAF will be the first of its kind worldwide and will offer a multi-GeV energy, high-intensity, high-duty-factor electron beam for use by the US nuclear physics community in research on the states of nuclear matter and the short-distance behavior of nuclei. The CEBAF project is largely in the conceptual design stage, with some components in the preliminary design stage. Construction is anticipated to begin in 1987 and be completed by 1992

  19. Utilization of electron accelerator in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Cabalfin, Estelita G. [Philippine Nuclear Research Institute, Quezon (Philippines)

    2003-02-01

    Radiosterilization of medical and surgical supplies, radiation treatment of consumer products such as food, pharmaceuticals and cosmetics, and the modification of polymers, crosslinking or curing, using gamma irradiation facilities in Philippine industries are overviewed. Philippine Nuclear Research Institute(PNRI) conducts bioburden determination, dose setting and validation of compatibility with radiation of product and packaging with the technical assistance of IAEA. The products with yields treated at the irradiation facility from 1996-2001 are shown in table. An electron accelerator of 10 MeV and 28 kW, established by Terumo Corporation, is used since 2000 for in-house radiation sterilization of syringes. Current regulations and regulatory authority in Philippines are also briefly introduced. Future processes such as radiation vulcanized natural rubber latex (RVNRL), use of carrageenan as hydrogel for dressing wounds and others and fermented bagasse as animal feed are now in progress. (S. Ohno)

  20. Utilization of electron accelerator in the Philippines

    International Nuclear Information System (INIS)

    Cabalfin, Estelita G.

    2003-01-01

    Radiosterilization of medical and surgical supplies, radiation treatment of consumer products such as food, pharmaceuticals and cosmetics, and the modification of polymers, crosslinking or curing, using gamma irradiation facilities in Philippine industries are overviewed. Philippine Nuclear Research Institute(PNRI) conducts bioburden determination, dose setting and validation of compatibility with radiation of product and packaging with the technical assistance of IAEA. The products with yields treated at the irradiation facility from 1996-2001 are shown in table. An electron accelerator of 10 MeV and 28 kW, established by Terumo Corporation, is used since 2000 for in-house radiation sterilization of syringes. Current regulations and regulatory authority in Philippines are also briefly introduced. Future processes such as radiation vulcanized natural rubber latex (RVNRL), use of carrageenan as hydrogel for dressing wounds and others and fermented bagasse as animal feed are now in progress. (S. Ohno)

  1. 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)

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. IL 2 Laser Accelerated Protons and Electrons in Medical Applications

    International Nuclear Information System (INIS)

    Ceccotti, T.; Martin, Ph.; Giulietti, A.

    2010-01-01

    protons for PBT is about 200 to 250 MeV corresponding to a range of 25 to 30 cm in a human body. Standard cyclotrons and synchrotrons able to get such energies are commercially available but their cost and their overall dimensions still restrains a large scale distribution of this kind of devices. The use of lasers should considerably reduce the size of such devices partly due to the fact that a local rather than generalized radio shielding is needed. In addition, lasers able to produce energetic ions are more and more compact, as the technology increase their capability. In order to evaluate the feasibility of a compact laser driven proton therapy facility compatible with the medical demands, an heterogeneous team, gathering top level competences from all the concerned research domains, has been constituted around the project SAPHIR. Our group shares this project with the ENSTA-LOA, the CEA-DAM, Amplitude Technologies, the Gustave Roussy Institute, the Curie Institute, the Centre de Protontherapie d'Orsay, Propulse s.a.s, Imagine Optic and Dosisoft. Laser-based Proton sources are usually obtained through the interaction of the intense laser field with a solid target. We will discuss recent encouraging results obtained in Saclay using a 'small' 100 TW, 25 fs laser, and novel acceleration mechanisms based on the ultra-high contrast interaction regime. Indeed, the complex motion of highly excited electrons builds-up an electrostatic field which accelerates ions to a few MeV energies at the plasma-vacuum interface. The hints to increase the maximum proton energies will be presented as well as the tailoring of their spectral distribution. IORT practice starts in the early 70's and is now currently employed in several hospitals worldwide with a growing interest. Whereas PBT directly acts on a well delimited cancer from outside the patient body, IORT applies after the cancer has been surgically removed. Tissues around the removed cancer location are

  9. 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)

  10. 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

  11. 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)

  12. 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)

  13. 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

  14. Microbunching and coherent acceleration of electrons by subcycle laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Rau, B.; Tajima, T. [Univ. of Texas, Austin, TX (United States). Physics Dept.; Hojo, H. [Univ. of Tsukuba (Japan). Plasma Research Center

    1997-05-01

    The pick up and acceleration of all plasma electrons irradiated by an intense, subcyclic laser pulse is demonstrated via analytical and numerical calculations. It is shown that the initial low emittance of the plasma electrons is conserved during the process of acceleration, leading to an extremely cold, bunched electron beam. Compression of the electron bunch along the longitudinal coordinate is naturally achieved due to the interaction of electrons and laser pulse. In this paper, the authors find the localized solutions to Maxwell`s equations of a subcyclic laser pulse and use these to determine the acceleration of charged particles and they suggest future application for this acceleration mechanism as low energy particle injector and as electron source for coherent x-ray generation.

  15. Dosimetry of laser-accelerated electron beams used for in vitro cell irradiation experiments

    International Nuclear Information System (INIS)

    Richter, C.; Kaluza, M.; Karsch, L.; Schlenvoigt, H.-P.; Schürer, M.; Sobiella, M.; Woithe, J.; Pawelke, J.

    2011-01-01

    The dosimetric characterization of laser-accelerated electrons applied for the worldwide first systematic radiobiological in vitro cell irradiation will be presented. The laser-accelerated electron beam at the JeTi laser system has been optimized, monitored and controlled in terms of dose homogeneity, stability and absolute dose delivery. A combination of different dosimetric components were used to provide both an online beam as well as dose monitoring and a precise absolute dosimetry. In detail, the electron beam was controlled and monitored by means of an ionization chamber and an in-house produced Faraday cup for a defined delivery of the prescribed dose. Moreover, the precise absolute dose delivered to each cell sample was determined by an radiochromic EBT film positioned in front of the cell sample. Furthermore, the energy spectrum of the laser-accelerated electron beam was determined. As presented in a previous work of the authors, also for laser-accelerated protons a precise dosimetric characterization was performed that enabled initial radiobiological cell irradiation experiments with laser-accelerated protons. Therefore, a precise dosimetric characterization, optimization and control of laser-accelerated and therefore ultra-short pulsed, intense particle beams for both electrons and protons is possible, allowing radiobiological experiments and meeting all necessary requirements like homogeneity, stability and precise dose delivery. In order to fulfill the much higher dosimetric requirements for clinical application, several improvements concerning, i.e., particle energy and spectral shaping as well as patient safety are necessary.

  16. Peking university superconducting accelerator facility for free electron laser

    CERN Document Server

    Zhao Kui; Hao Jian Kui; Huang Sen Lin; Lu Xiang Yang; Quan Sheng Wen; Wang Li; Xiang Rong; Zhang Bao Cheng; Zhu Feng; Zhuang Jie Ji

    2002-01-01

    Peking University Superconducting Accelerator Facility (PKU-SCAF) is to generate high-quality electron beams with high average current. It is mainly composed of a DC-SC photocathode injector and a superconducting accelerator. It will operate in CW mode. The energy of the electrons is 20-35 MeV and the emittance is <15 pi mm mrad. PKU-SCAF will be used for Free Electron Lasers.

  17. 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

  18. Reble, a radially converging electron beam accelerator

    International Nuclear Information System (INIS)

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

    1976-01-01

    The Reble accelerator at Sandia Laboratories is described. This accelerator was developed to provide an experimental source for studying the relevant diode physics, beam propagation, beam energy deposition in a gas using a radially converging e-beam. The nominal parameters for Reble are 1 MV, 200 kA, 20 ns e-beam pulse. The anode and cathode are concentric cylinders with the anode as the inner cylinder. The radial beam can be propagated through the thin foil anode into the laser gas volume. The design and performance of the various components of the accelerator are presented

  19. 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)

  20. 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)

  1. Electron acceleration using laser produced plasmas

    CERN Multimedia

    CERN. Geneva; Landua, Rolf

    2005-01-01

    Low density plasmas have long been of interest as a potential medium for particle acceleration since relativistic plasma waves are capable of supporting electric fields greater than 100 GeV/m. The physics of particle acceleration using plasmas will be reviewed, and new results will be discussed which have demonstrated that relatively narrow energy spread (<3%) beams having energies greater than 100 MeV can be produced from femtosecond laser plasma interactions. Future experiments and potential applications will also be discussed.

  2. 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)

  3. Measurement of Electron Clouds in Large Accelerators by Microwave Dispersion

    CERN Document Server

    De Santis, S; Caspers, Friedhelm; Krasnykh, A; Kroyer, T; Pivi, MTF; Sonnad, KG

    2008-01-01

    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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. Regular and stochastic acceleration of electrons in the surfatron configuration

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, J.T. [Inst. Superior Tecnico, Lisboa (Portugal). Centro de Electrodinamica

    1996-11-01

    We present here a theoretical approach to the problem of electron acceleration using the surfatron configuration. We show first how the acceleration process can be described with the help of a perturbation technique. Secondly, we discuss the transition from a regular to a stochastic acceleration regime, making use of the results of Hamiltonian chaos. Finally, we reduce the particle dynamics to a discrete map, generalizing the Karney map to the relativistic domain. (orig.).

  9. 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

  10. Focus measurement of electron linear accelerator

    International Nuclear Information System (INIS)

    Su Zhijun; Xin Jian; Jia Qinglong

    2007-01-01

    Many personal factors would influence the result of the focus measurement of linear accelerator using the conventional sandwich method. This paper presents a modified method which applies a film scanning meter to scan the X-ray image film got by sandwich method for obtaining a greyscale distribution, then the full width at half maximum value of greyscale distribution represents the focus size. The method can eliminates disadvantage influence from accelerator radiant field asymmetry by quadratic polynomial fitting and measures peak width at half height instead of stripe statistic. (authors)

  11. The First Two Electron Linear Accelerators in South Mrica

    African Journals Online (AJOL)

    was apparent that the linear accelerator showed great promise by its inherent capability to produce intense elec- tron beam currents at high energies. PRINCIPLE OF OPERATION. The.basic microwave linear electron accelerator system consists of a power supply providing high voltage direct current power to the modulator, ...

  12. Performance of the Fitch generator in a nanosecond electron accelerator

    International Nuclear Information System (INIS)

    Chernyj, V.V.

    1976-01-01

    The operation of the Fitch generator in the nanosecond electron accelerator is discussed. The operating principle of the generator is based on the inversion of the voltage at the storage capacitances. Only one discharger is employed in the discharge circuit of the generator which provides for decreasing the generator impedance to 24 Ohms. The maximum accelerating voltage equals 0.6 MV

  13. Effective radiological safety program for electron linear accelerators

    International Nuclear Information System (INIS)

    Swanson, W.P.

    1980-10-01

    An outline is presented of some of the main elements of an electron accelerator radiological safety program. The discussion includes types of accelerator facilities, types of radiations to be anticipated, activity induced in components, air and water, and production of toxic gases. Concepts of radiation shielding design are briefly discussed and organizational aspects are considered as an integral part of the overall safety program

  14. 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)

  15. Induction accelerators and free-electron lasers at LLNL

    International Nuclear Information System (INIS)

    Briggs, R.J.

    1989-01-01

    Linear induction accelerators have been developed to produce pulses of charged particles at voltages exceeding the capabilities of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine. The advent of magnetic pulse power systems makes sustained operation at high repetition rates practical, and high-average-power capability is very likely to open up many new applications of induction machines. In part A of this paper, the US induction linac technology is surveyed emphasizing electron machines. A simplified description is given of how induction machines couple energy to the electron beam to illustrate many general issues that designers of high-brightness and high-average-power induction linacs must consider. An example is given of the application of induction accelerator technology to the relativistic klystron, a power source for high-gradient accelerators. In part B the application of LIAs to free-electron lasers is addressed. The multikiloampere peak currents available from linear induction accelerators make high-gain, free-electron laser amplifier configurations feasible. High extraction efficiencies in a single pass of the electron beam are possible if the wiggler parameters are appropriately tapered, as recently demonstrated at millimeter wavelengths on the 4-MeV ELF facility. Key issues involved in extending the technology to shorter wavelengths and higher average powers are described. Current FEL experiments at LLNL are discussed. 5 references, 16 figures, 1 table

  16. Neutron radiation from medical electron accelerators

    International Nuclear Information System (INIS)

    McCall, R.C.

    1983-01-01

    A method is described using simple gold foils and relatively inexpensive moderators to measure neutron fluences, both fast nd thermal, which then can be converted to dose equivalent using a few simple formulas. The method is sensitive, easy to calibrate, and should work at most accelerators regardless of energy or room geometry

  17. Electron accelerating unit for streak image tubes

    Indian Academy of Sciences (India)

    XIANG LI and JINGJIN ZHANG. Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education and Guangdong Province, College of Optoelectronic Engineering,. Shenzhen University, Shenzhen ... There are three advantages of the accelerating unit. In the pulsed mode, a pulsed voltage is applied to the ...

  18. 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)

  19. 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

  20. Application of time release electron donors and electron acceptors for accelerated bioremediation

    International Nuclear Information System (INIS)

    Joksimovich, V.; Koenigsberg, S.

    2002-01-01

    Currently, there are limited options for cost effective approaches to soil and groundwater contamination. One technology that has proven its potential involves the use of time release electron acceptors to accelerate the natural bioattenuation of aerobically degradable compounds and time release electron donors to accelerate the natural bioattenuation of anaerobic compounds. This technology enjoys its reputations as a sensible strategy for engineering accelerated bioattenuation, because it delivers results while 1) limiting or eliminating design, capital and management costs and 2) allowing for the engineering of a low-impact application and a subsequently invisible remediation process. Oxygen Release Compound (ORC ) is proprietary formulation of intercalated magnesium peroxide that releases oxygen slowly, for about a year, and facilitates the aerobic degradation of a range of environmental contaminants including petroleum hydrocarbons, certain chlorinated hydrocarbons, ether oxygenates and nitroaromatics. The history of ORC's introduction and acceptance represents a model for the evolution of an innovative technology. This statement comes by virtue of the fact that since 1994 ORC has been used on over 7000 sites worldwide and has been the subject of an extensive body of literature. Hydrogen Release Compound (HRC) is also a proprietary polylactate ester that is food grade and, upon being deposited into the aquifer, is slowly hydrolyzed to release lactic acid and other organic acid derivatives for about one to two years. The organic acids are fermented to hydrogen, which in turn donates electrons that drive reductive bioattenuation processes. This is primarily directed at a wide range of chlorinated hydrocarbons, but can be applied to the remediation of metals by redox induced precipitation. HRC has now been used on over 220 sites, which we believe make it the most widely used electron donor for accelerating bioattenuation. ORC and HRC can be configured as a

  1. 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.

  2. Suprathermal electron acceleration during reconnection onset in the magnetotail

    Directory of Open Access Journals (Sweden)

    A. Vaivads

    2011-10-01

    Full Text Available We study one event of reconnection onset associated to a small substorm on 27 September 2006 by using Cluster observations at inter-spacecraft separation of about 10 000 km. We focus on the acceleration of suprathermal electrons during different stages of reconnection. We show that several distinct stages of acceleration occur: (1 moderate acceleration during reconnection of pre-existing plasma sheet flux tubes, (2 stronger acceleration during reconnection of lobe flux tubes, (3 production of the most energetic electrons within dipolarization fronts (magnetic pile-up regions. The strongest acceleration is reached at the location of Bz maxima inside the magnetic pile-up region where the reconnection jet stops. Very strong localized dawn-dusk electric field are observed within the magnetic pile-up regions and are associated to most of the magnetic flux transport.

  3. 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)

  4. 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...

  5. Plasma astrophysics: Acceleration of killer electrons

    OpenAIRE

    Horne, Richard Bertram

    2007-01-01

    Relativistic electrons in the outer Van Allen belt wreak havoc with satellites in geosynchronous orbit, but how they reach such high energies has been unclear. New data identify gyro-resonant wave-particle interactions as the culprit.

  6. Electron acceleration in a wavy shock front

    Czech Academy of Sciences Publication Activity Database

    Vandas, Marek; Karlický, Marian

    2011-01-01

    Roč. 531, July (2011), A55/1-A55/8 ISSN 0004-6361 R&D Projects: GA AV ČR(CZ) IAA300030701; GA MŠk(CZ) ME09009; GA ČR GA205/09/0170; GA ČR GAP209/10/1680 Grant - others:EU(XE) EC FP7 SWIFF 263340 Institutional research plan: CEZ:AV0Z10030501 Keywords : shock waves * acceleration of particles * magnetic fields * solar radio radiation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.587, year: 2011

  7. 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

  8. 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.

  9. Laser-driven dielectric electron accelerator for radiobiology researches

    Science.gov (United States)

    Koyama, Kazuyoshi; Matsumura, Yosuke; Uesaka, Mitsuru; Yoshida, Mitsuhiro; Natsui, Takuya; Aimierding, Aimidula

    2013-05-01

    In order to estimate the health risk associated with a low dose radiation, the fundamental process of the radiation effects in a living cell must be understood. It is desired that an electron bunch or photon pulse precisely knock a cell nucleus and DNA. The required electron energy and electronic charge of the bunch are several tens keV to 1 MeV and 0.1 fC to 1 fC, respectively. The smaller beam size than micron is better for the precise observation. Since the laser-driven dielectric electron accelerator seems to suite for the compact micro-beam source, a phase-modulation-masked-type laser-driven dielectric accelerator was studied. Although the preliminary analysis made a conclusion that a grating period and an electron speed must satisfy the matching condition of LG/λ = v/c, a deformation of a wavefront in a pillar of the grating relaxed the matching condition and enabled the slow electron to be accelerated. The simulation results by using the free FDTD code, Meep, showed that the low energy electron of 20 keV felt the acceleration field strength of 20 MV/m and gradually felt higher field as the speed was increased. Finally the ultra relativistic electron felt the field strength of 600 MV/m. The Meep code also showed that a length of the accelerator to get energy of 1 MeV was 3.8 mm, the required laser power and energy were 11 GW and 350 mJ, respectively. Restrictions on the laser was eased by adopting sequential laser pulses. If the accelerator is illuminated by sequential N pulses, the pulse power, pulse width and the pulse energy are reduced to 1/N, 1/N and 1/N2, respectively. The required laser power per pulse is estimated to be 2.2 GW when ten pairs of sequential laser pulse is irradiated.

  10. 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

  11. 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

  12. 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

  13. Economy in utilizing electron beam accelerators

    International Nuclear Information System (INIS)

    Takahashi, Masao

    1980-01-01

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

  14. 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.

  15. 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.)

  16. 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.

  17. Manipulation and electron-oscillation-measurement of laser accelerated electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Kotaki, H; Hayashi, Y; Kawase, K; Mori, M; Kando, M; Homma, T; Koga, J K; Daido, H; Bulanov, S V, E-mail: kotaki.hideyuki@jaea.go.jp [Advanced Photon Research Center, Japan Atomic Energy Agency, 8-1-7, Umemidai, Kizugawa, Kyoto (Japan)

    2011-01-15

    Monoenergetic electron beams have been generated in the self-injection scheme of laser acceleration. In applications of these laser accelerated electron beams, stable and controllable electron beams are necessary. A stable electron beam is generated in the self-injection scheme by using a nitrogen gas jet target. We found the profile of the electron beam was manipulated by rotating the laser polarization. The electron beam is in the first bucket of the wake wave. In the energy space, transverse oscillation is observed when the laser pulse has S-polarization. The direction of the electron beam is controlled by the gas jet position.

  18. 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

  19. Down-ramp injection and independently controlled acceleration of electrons in a tailored laser wakefield accelerator

    CERN Document Server

    Hansson, M.; Davoine, X.; Ekerfelt, H.; Svensson, K.; Persson, A.; Wahlström, C.-G.; Lundh, O.; 10.1103/PhysRevSTAB.18.071303

    2015-01-01

    We report on a study on controlled injection of electrons into the accelerating phase of a plasma wakefield accelerator by tailoring the target density distribution using two independent sources of gas. The tailored density distribution is achieved experimentally by inserting a narrow nozzle, with an orifice diameter of only 400  μm , into a jet of gas supplied from a 2 mm diameter nozzle. The combination of these two nozzles is used to create two regions of different density connected by a density gradient. Using this setup we show independent control of the charge and energy distribution of the bunches of accelerated electron as well as decreased shot-to-shot fluctuations in these quantities compared to self-injection in a single gas jet. Although the energy spectra are broad after injection, simulations show that further acceleration acts to compress the energy distribution and to yield peaked energy spectra.

  20. Techniques for increasing the reliability of accelerator control system electronics

    International Nuclear Information System (INIS)

    Utterback, J.

    1993-09-01

    As the physical size of modern accelerators becomes larger and larger, the number of required control system circuit boards increases, and the probability of one of those circuit boards failing while in service also increases. In order to do physics, the experimenters need the accelerator to provide beam reliably with as little down time as possible. With the advent of colliding beams physics, reliability becomes even more important due to the fact that a control system failure can cause the loss of painstakingly produced antiprotons. These facts prove the importance of keeping reliability in mind when designing and maintaining accelerator control system electronics

  1. 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.

  2. 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)

  3. Electron Accelerators for Radioactive Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lia Merminga

    2007-10-10

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

  4. 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.

  5. Ion and electron Van de Graaff accelerators of Kyoto University

    International Nuclear Information System (INIS)

    Fukuzawa, F.; Imanishi, N.; Tomita, M.; Norisawa, K.; Yoshida, K.; Ohdaira, T.

    1990-01-01

    Two Van de Graaff accelerators are available at the Uji campus of Kyoto University. One is a 4MV machine, which is used for heavy ion acceleration, while the other is a 2MV machine for electron acceleration. These machines have been modified in various parts and currently used very actively in many fields of investigation. Important modifications of the 4MV machine are: use of a newly developed accelerating tube, addition of a charge-changer before the analyzing magnet, renewal of the charging belt, and development of a microbeam system for PIXE and RBS analysis. An attempt is now being made to accelerate micro-particles using the 2MV machine. The new accelerating tube has bucket type electrodes with large accelerating apertures. By charge-changing the accelerated 1+ ions to higher charge states, 2+, 3+, ..., at the entrance of the analyzing magnet, Ar ions with energies of up to 2.73, 6.21, .... MeV can be deflected to the duct. Scanning microbeam PIXE and RBS are powerful tools for analysis of spatial elemental distribution. Calculations suggest that a beam size of about 3 μm can be attained by using an object aperture of 10μm in diameter and controlling the beam divergence within 10μ rad in both directions. (N.K.)

  6. Bunch monitor for an S-band electron linear accelerator

    International Nuclear Information System (INIS)

    Otake, Yuji; Nakahara, Kazuo

    1991-01-01

    The measurement of bunch characteristics in an S-band electron linear accelerator is required in order to evaluate the quality of accelerated electron beams. A new-type bunch monitor has been developed which combines micro-stripline technology with an air insulator and wall-current monitoring technology. The obtained time resolution of the monitor was more than 150 ps. This result shows that the monitor can handle the bunch number of an S-band linac. The structure of the monitor is suitable for being installed in the vacuum area, since it is constructed of only metal and ceramic parts. It can therefore easily be employed in an actual machine

  7. 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.)

  8. Concept of an electron accelerator driven molten salt subcritical reactor

    International Nuclear Information System (INIS)

    Brolly, A.; Vertes, P.

    2005-01-01

    Concept and analysis of an electron accelerator driven molten salt subcritical system are presented. The analysis covers the neutron source optimization and burnup history with continuous feeding of TRU into the reactor. Effect of long time operation on TRU consumption and corresponding energy production is considered. It seems that with an electron accelerator of 150 MeV energy and with technically acceptable current it is possible to maintain a subcritical reactor on a reasonable power level while it consumes considerable amount of TRU coming from online chemical processing of spent fuels. (authors)

  9. 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

  10. ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS.

    Energy Technology Data Exchange (ETDEWEB)

    WEI,J.; MACEK,R.J.

    2002-04-14

    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.

  11. Electron cloud in the CERN accelerator complex

    CERN Document Server

    AUTHOR|(CDS)2069325; Bartosik, Hannes; Belli, Eleonora; Iadarola, Giovanni; Li, Kevin Shing Bruce; Mether, Lotta Maria; Romano, Annalisa; Schenk, Michael

    2016-01-01

    Operation with closely spaced bunched beams causes the build-up of an Electron Cloud (EC) in both the LHC and the two last synchrotrons of its injector chain (PS and SPS). Pressure rise and beam instabilities are observed at the PS during the last stage of preparation of the LHC beams. The SPS was affected by coherent and incoherent emittance growth along the LHC bunch train over many years, before scrubbing has finally suppressed the EC in a large fraction of the machine. When the LHC started regular operation with 50 ns beams in 2011, EC phenomena appeared in the arcs during the early phases, and in the interaction regions with two beams all along the run. Operation with 25 ns beams (late 2012 and 2015), which is nominal for LHC, has been hampered by EC induced high heat load in the cold arcs, bunch dependent emittance growth and degraded beam lifetime. Dedicated and parasitic machine scrubbing is presently the weapon used at the LHC to combat EC in this mode of operation. This talk summarises the EC experi...

  12. 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

  13. 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.

  14. 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

  15. Wave acceleration of electrons in the Van Allen radiation belts.

    Science.gov (United States)

    Horne, Richard B; Thorne, Richard M; Shprits, Yuri Y; Meredith, Nigel P; Glauert, Sarah A; Smith, Andy J; Kanekal, Shrikanth G; Baker, Daniel N; Engebretson, Mark J; Posch, Jennifer L; Spasojevic, Maria; Inan, Umran S; Pickett, Jolene S; Decreau, Pierrette M E

    2005-09-08

    The Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth, that the long established theory of acceleration by radial diffusion is inadequate; the electrons are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the electron flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.

  16. Maps for coupled electron and ion clouds in accelerators

    Directory of Open Access Journals (Sweden)

    Ubaldo Iriso

    2006-07-01

    Full Text Available Electron clouds sometimes limit accelerator performance by their appearance when the circulating bunch population exceeds a threshold value. Dynamical models of cloud buildup, and of the phase transition from “cloud off” to “cloud on”, are enhanced when simple coupling between electron and ion clouds is included. Maps are then capable of reproducing the first order phase transitions sometimes seen in practice. They also predict that hysteresis, period doubling, and chaotic phenomena may be observed.

  17. Monitoring and control system of the Saclay electron linear accelerator

    International Nuclear Information System (INIS)

    Lafontaine, Antoine

    1974-01-01

    A description is given of the automatic monitoring and control system of the 60MeV electron linear accelerator of the Centre d'Etudes Nucleaires de Saclay. The paper is mostly concerned with the programmation of the system. However, in a real time device, there is a very close association between computer and electronics, the latter are therefore described in details and make up most of the paper. [fr

  18. New initiatives for producing high current electron accelerators

    International Nuclear Information System (INIS)

    Faehl, R.J.; Keinigs, R.K.; Pogue, E.W.

    1996-01-01

    New classes of compact electron accelerators able to deliver multi-kiloamperes of pulsed 10-50 MeV electron beams are being studied. One class is based upon rf linac technology with dielectric-filled cavities. For materials with ε/ε o >>1, the greatly increased energy storage permits high current operation. The second type is a high energy injected betatron. Circulating current limits scale as Β 2 γ 3

  19. Electron injector for high-voltage model of collective accelerator

    International Nuclear Information System (INIS)

    Belikov, V.V.; Zvyagintsev, A.V.; Lymar', A.G.; Martynenko, P.A.; Khizhnyak, N.A.

    1987-01-01

    The design and test results of an electron gun with the beam compression and axial hole aimed at collective acceleration are presented. The electron gun is tested at 150 kV, the pulse duration being 12 ms. The hallow beam has 10 mm in diameter, with 1 mm thick wall, that corresponds to the compression degree of 200. The beam microperveance is 4.5 mA/V 3/2

  20. 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

  1. Ultrashort laser pulse driven inverse free electron laser accelerator experiment

    Directory of Open Access Journals (Sweden)

    J. T. Moody

    2016-02-01

    Full Text Available In this paper we discuss the ultrashort pulse high gradient inverse free electron laser accelerator experiment carried out at the Lawrence Livermore National Laboratory which demonstrated gradients exceeding 200  MV/m using a 4 TW 100 fs long 800 nm Ti:Sa laser pulse. Due to the short laser and electron pulse lengths, synchronization was determined to be one of the main challenges in this experiment. This made necessary the implementation of a single-shot, nondestructive, electro-optic sampling based diagnostics to enable time-stamping of each laser accelerator shot with <100  fs accuracy. The results of this experiment are expected to pave the way towards the development of future GeV-class IFEL accelerators.

  2. 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.

  3. Procedures manual for the Oak Ridge Electron Linear Accelerator

    International Nuclear Information System (INIS)

    Todd, H.A.

    1979-01-01

    The Procedures Manual for the Oak Ridge Electron Linear Accelerator contains specific information pertaining to operation and safety of the facility. Items such as the interlock system, radiation monitoring, emergency procedures, night shift and weekend operation, and maintenance are discussed in detail

  4. Advanced ponderomotive description of electron acceleration in ICRF discharge initiation

    Directory of Open Access Journals (Sweden)

    Wauters Tom

    2017-01-01

    An example for plasma production by the TOMAS ICRF system is given. Following the described conditions it can be derived that plasma production is (i most efficient close to the antenna straps (few cm's where the field gradient and amplitude are large, and (ii that the lower frequency field accelerates electrons more easily for a given antenna voltage.

  5. Calibration of an Electron Linear Accelerator using an acrylic puppet

    International Nuclear Information System (INIS)

    Guzman C, C.S.; Picon C, C.

    1998-01-01

    The finality of this work is to find the dose for electron beams using acrylic puppets and inter comparing with the measurements in water, found also its respective conversion factor. With base in this, its may be realize interesting measurements for the good performance of a linear accelerator and special clinical treatments in less time. (Author)

  6. The First Two Electron Linear Accelerators in South Africa | Minnaar ...

    African Journals Online (AJOL)

    The electron linear accelerator is considered by many leading radiotherapy centres throughout the world as the most suitable equipment for the treatment of cancer. There are good reasons for this opinion, and some physical aspects are summarised here. S. Afr. Med. J., 48, 1004 (1974) ...

  7. 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

  8. 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)

  9. 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...

  10. 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

  11. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    G. Wittig

    2015-08-01

    Full Text Available A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  12. Evanescent-wave acceleration of femtosecond electron bunches

    CERN Document Server

    Zawadzka, J; Carey, J J; Wynne, K

    2000-01-01

    A 150-fs 800-nm 1-mu J laser was used to excited surface plasmons in the Kretschmann geometry in a 500-A silver film. Multiphoton excitation results in the emission of femtosecond electron bunches (40 fC) as had been seen before. The electron beam is highly directional and perpendicular to the prism surface. A time-of-flight setup has been used to measure the kinetic-energy distribution of the photoelectrons. Surprisingly, we find that this distribution extends to energies as high as 40 eV. Theoretical calculations show that these high energies may be due to acceleration in the evanescent laser field that extends from the silver film out into the vacuum. These results suggest that femtosecond pulses with more energy per pulse or longer wavelength may be used to accelerate electrons to the keV or even MeV level.

  13. Laser Acceleration of Electrons in Shock Wave Enhanced Gas Jets

    Science.gov (United States)

    Kaganovich, Dmitri; Helle, Michael; Gordon, Daniel; Ting, Antonio

    2012-10-01

    Controlling the gas density gradient and profile is important for electron and proton acceleration. Using an optimized gas density profile, we have demonstrated 40 times higher electron energy compared to a Gaussian gas jet without lost of charge or stability. Propagation of a shock wave through a gas jet can modify the gas density profile and create sharp density gradients [1, 2]. Using different shock waves energies and shock originating positions, we were able to modify the plasma density profile of a ``typical'' Gaussian gas jet into a variety of profiles, from thin (foil-like) structure to elongated profiles with fast rise and slow fall. We used a plasma bubble Cherenkov diagnostic [3, 4] to optimize the acceleration process. Accelerated electron energy and charge were cross-correlated with the second harmonic diagnostic signal. The optimized gas density profile generated stable 0.5 nC of 40 MeV electrons using a 10 TW laser. The shock wave modified gas jet can be used as a stand alone electron source or as an injector coupled to additional acceleration structures. We demonstrated stable injection of electrons from the shock wave modified gas jet into a lower density plasma. The results are also being studied with numerical simulations. [4pt] [1] D. Kaganovich et al., Physics of Plasmas 18, 120701 (2011)[0pt] [2] D. Kaganovich et al., Applied Physics Letters 97, 191501 (2010)[0pt] [3] D. F. Gordon, et al., Phys. Rev. Lett. 101, 045004 (2008)[0pt] [4] M. H. Helle et al., Phys. Rev. Lett. 105, 105001 (2010)

  14. Electron acceleration in Titan's ionosphere and Saturn's kilometric radiation

    Science.gov (United States)

    Zaitsev, V.; Shaposhnikov, V.; Rucker, H.

    2008-09-01

    Prior to Cassini flights the solar wind was considered as the only source of electrons responsible for Saturn kilometric radiation (SKR). Detected correlation of the SKR occurrence and Titan position at its orbit points out the energy source of SKR associated with Titan [1], [2]. The observed correlation is not the only indication of acceleration mechanism in the satellite ionosphere. Spacecrafts Voyager I and II discovered ultraviolet airglow from excited molecules in Titan's atmosphere. Estimations showed that the observed radiation intensity corresponded to energy input (3-5)x109W into Titan's atmosphere. It was also shown that solar photons and photo-electrons are not able to provide the necessary energy input, and energetic magnetosphere electrons can give not more than [3]. The presence of acceleration mechanism in Titan' ionosphere is also confirmed by the results of Radio and Plasma Wave Science (RPWS) experiments during Cassini flyby through Titan's atmosphere tail: energetic electrons and ions with parameters different from those for particles coming from Saturn's magnetosphere have been discovered there [4]. ~ 2×109 W In this contribution we consider electron acceleration mechanism in Titan's ionosphere which was successfully used for explanation of observed Io influence on decametric radio emission from Jupiter [5], [6]. According to suggested mechanism electron acceleration in the ionosphere occurs due to electric field of charge separation. This field is of the order of induced electric field, but has a field-aligned component. Under Titan's conditions the accelerated electron energy can reach 10 keV that is sufficient for SKR generation. Acceleration mechanism power is enough also for explanation of ultraviolet airglow from Titan. References [1] Farrell, W. M. Et al. (2005) Geophys. Res.Lett., 32, L18107, doi:10.1029/2005GL023449. [2] Menietti, J. D. et al. (2007) JGR, 112, A08211, doi:10.1029/2007JA012331. [3] Hunten, D. M.et al. (1984) Titan, in

  15. 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.

  16. Accelerating Quinoline Biodegradation and Oxidation with Endogenous Electron Donors.

    Science.gov (United States)

    Bai, Qi; Yang, Lihui; Li, Rongjie; Chen, Bin; Zhang, Lili; Zhang, Yongming; Rittmann, Bruce E

    2015-10-06

    Quinoline, a recalcitrant heterocyclic compound, is biodegraded by a series of reactions that begin with mono-oxygenations, which require an intracellular electron donor. Photolysis of quinoline can generate readily biodegradable products, such as oxalate, whose bio-oxidation can generate endogenous electron donors that ought to accelerate quinoline biodegradation and, ultimately, mineralization. To test this hypothesis, we compared three protocols for the biodegradation of quinoline: direct biodegradation (B), biodegradation after photolysis of 1 h (P1h+B) or 2 h (P2h+B), and biodegradation by adding oxalate commensurate to the amount generated from photolysis of 1 h (O1+B) or 2 h (O2+B). The experimental results show that P1h+B and P2h+B accelerated quinoline biodegradation by 19% and 50%, respectively, compared to B. Protocols O1+B and O2+B also gave 19% and 50% increases, respectively. During quinoline biodegradation, its first intermediate, 2-hydroxyquinoline, accumulated gradually in parallel to quinoline loss but declined once quinoline was depleted. Mono-oxygenation of 2-hydroxyquinoline competed with mono-oxygenation of quinoline, but the inhibition was relieved when extra electrons donors were added from oxalate, whether formed by UV photolysis or added exogenously. Rapid oxalate oxidation stimulated both mono-oxygenations, which accelerated the overall quinoline oxidation that provided the bulk of the electron donor.

  17. 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.

  18. Current and future industrial application of electron accelerators in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Siri-Upathum, Chyagrit [Chulalongkorn Univ., Faculty of Engineering, Bangkok (Thailand)

    2003-02-01

    Industrial applications of electron accelerators in Thailand, first introduced in 1997 for radiation sterilized products such as doctor gown, pampas, feminine napkin etc followed by installation of accelerators, one with energies at 20 MV and the other at 5 MV to produce new value added products like gem stones, topaz, tourmaline and zircon. The machines operate in pulse mode and is also used for irradiation services for food and sterilized products treatment. The need for low and medium energy accelerators in radiation technology is stressed. They are to be used for crosslinking of electrical wire and cable, heat shrinkable materials, low protein concentrated rubber latex, rubber wood furniture and parts, and silk protein degradation. The role of governmental organizations like Nuclear Research Institute (OAEP) and universities in stimulating the utilization of radiation processing in Thailand is strengthened. (S. Ohno)

  19. Current and future industrial application of electron accelerators in Thailand

    International Nuclear Information System (INIS)

    Siri-Upathum, Chyagrit

    2003-01-01

    Industrial applications of electron accelerators in Thailand, first introduced in 1997 for radiation sterilized products such as doctor gown, pampas, feminine napkin etc followed by installation of accelerators, one with energies at 20 MV and the other at 5 MV to produce new value added products like gem stones, topaz, tourmaline and zircon. The machines operate in pulse mode and is also used for irradiation services for food and sterilized products treatment. The need for low and medium energy accelerators in radiation technology is stressed. They are to be used for crosslinking of electrical wire and cable, heat shrinkable materials, low protein concentrated rubber latex, rubber wood furniture and parts, and silk protein degradation. The role of governmental organizations like Nuclear Research Institute (OAEP) and universities in stimulating the utilization of radiation processing in Thailand is strengthened. (S. Ohno)

  20. Probing SEP Acceleration Processes With Near-relativistic Electrons

    International Nuclear Information System (INIS)

    Haggerty, Dennis K.; Roelof, Edmond C.

    2009-01-01

    Processes in the solar corona are prodigious accelerators of near-relativistic electrons. Only a small fraction of these electrons escape the low corona, yet they are by far the most abundant species observed in Solar Energetic Particle events. These beam-like energetic electron events are sometimes time-associated with coronal mass ejections from the western solar hemisphere. However, a significant number of events are observed without any apparent association with a transient event. The relationship between solar energetic particle events, coronal mass ejections, and near-relativistic electron events are better ordered when we classify the intensity time profiles during the duration of the beam-like anisotropies into three broad categories: 1) Spikes (rapid and equal rise and decay); 2) Pulses (rapid rise, slower decay); and 3) Ramps (rapid rise followed by a plateau). We report on the results of a study that is based on our catalog (covering nearly the complete Solar Cycle 23) of 216 near-relativistic electron events and their association with: solar electromagnetic emissions, shocks driven by coronal mass ejections, models of the coronal magnetic fields and energetic protons. We conclude that electron events with time-intensity profiles of Spikes and Pulses are associated with explosive events in the low corona while events with time-intensity profiles of Ramps are associated with the injection/acceleration process of the CME driven shock.

  1. 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)

  2. Single-pulse electrons from a linear accelerator

    International Nuclear Information System (INIS)

    Antoku, Shigetoshi; Sunayashiki, Tadashi; Takeoka, Seiji; Kato, Kazushi

    1976-01-01

    The electronic circuits of a 35 MeV linear accelerator at Hiroshima University were modified to produce single-pulse electrons. Single-pulse electrons were obtained by synchronizing one of eight pulses from an electron gun modulator, 120 pps, to one of the micro-waves from a klystron, 15 pps. After single-pulse electrons were discharged, a signal was relayed to a stop-gate circuit from a binary scaler which was connected to the gun modulator. Although reproducibility of single-pulse electrons and stability of electron output per pulse were not completely satisfactory, it was possible to use for radiobiological studies. Biological effects of single-pulse electrons (energy: 25 MeV, dose rate: 10 10 rad/min) on cultured mammalian cells and on mice were nearly equal to those of multi-pulse electrons (25 MeV, 10 7 rad/min) and Co-60 γ-rays (dose rate: 100 rad/min). (auth.)

  3. Cost analysis of low energy electron accelerator for film curing

    International Nuclear Information System (INIS)

    Ochi, Masafumi

    2003-01-01

    Low energy electron accelerators are recognized as one of the advanced curing means of converting processes for films and papers. In the last three years the price of the accelerator equipment has been greatly reduced. The targeted application areas are mainly processes of curing inks, coatings, and adhesives to make packaging materials. The operating cost analyses were made for electron beam (EB) processes over the conventional ones without EB. Then three new proposals for cost reduction of EB processes are introduced. Also being developed are new EB chemistries such as coatings, laminating adhesives and inks. EB processes give instantaneous cure and EB chemistries are basically non solvent causing less VOC emission to the environment. These developments of both equipment and chemistries might have a potential to change conventional packaging film industries. (author)

  4. Inverse free electron laser accelerator for advanced light sources

    Directory of Open Access Journals (Sweden)

    J. P. Duris

    2012-06-01

    Full Text Available We discuss the inverse free electron laser (IFEL scheme as a compact high gradient accelerator solution for driving advanced light sources such as a soft x-ray free electron laser amplifier or an inverse Compton scattering based gamma-ray source. In particular, we present a series of new developments aimed at improving the design of future IFEL accelerators. These include a new procedure to optimize the choice of the undulator tapering, a new concept for prebunching which greatly improves the fraction of trapped particles and the final energy spread, and a self-consistent study of beam loading effects which leads to an energy-efficient high laser-to-beam power conversion.

  5. BOOK REVIEW: Electron acceleration in the aurora and beyond

    Science.gov (United States)

    McClements, K. G.

    1999-08-01

    Duncan Bryant is a retired space plasma physicist who spent most of his career at the Rutherford-Appleton Laboratory in Oxfordshire, England. For many years he has been challenging a widely accepted theory, that auroral electrons are accelerated by double layers, on the grounds that it contains a fundamental error (allegedly, an implicit assumption that charged particles can gain energy from conservative fields). It is, of course, right that models of particle acceleration in natural plasmas should be scrutinized carefully in terms of their consistency with basic physical principles, and I believe that Dr Bryant has performed a valuable service by highlighting this issue. He maintains that auroral electron acceleration by double layers is fundamentally untenable, and that acceleration takes place instead via resonant interactions with lower hybrid waves. In successive chapters, he asserts that essentially the same process can account for electron acceleration observed at the Earth's bow shock, in the neighbourhood of an `artificial comet' produced as part of the Active Magnetospheric Particle Explorers (AMPTE) space mission in 1984/85, in the solar wind, at the Earth's magnetopause, and in the Earth's magneto- sphere. The evidence for this is not always convincing: waves with frequencies of the order of the lower hybrid resonance are often observed in these plasma environments, but in general it is difficult to identify clearly which wave mode is being observed (whistlers, for example, have frequencies in approximately the same range as lower hybrid waves). Moreover, it is not at all clear that the waves which are observed, even if they were of the appropriate type, would have sufficient intensity to accelerate electrons to the extent observed. The author makes a persuasive case, however, that acceleration in the aurora, and in other plasma environments accessible to in situ measurements, involves some form of wave turbulence. In Chapter 2 it is pointed out that

  6. Design and fabrication of a continuous wave electron accelerating structure

    International Nuclear Information System (INIS)

    Takahashi, Jiro

    1997-01-01

    The Physics Institute of Sao Paulo University, SP, Brazil is fabricating a 31 MeV cw racetrack microtron (RTM) designed for nuclear physics research. This is a two-stage microtron that includes a 1.93 MeV injector linac feeding a five-turn microtron booster. After 28 turns, the main microtron delivers a 31 MeV continuous electron beam. The objective of this work is the development and fabrication of an advanced, beta=l, cw accelerating structure for the main microtron. The accelerating structure will be a side-coupled structure (SCS). We have chosen this kind of cavity, because it presents good vacuum properties, allows operation at higher accelerating electric fields and has a shunt impedance better than 81 MQ/m, with a high coupling factor ( 3 - 5%). The engineering design is the Los Alamos one. There will be two tuning plungers placed at both ends of the accelerating structure. They automatically and quickly compensate for the variation in the resonance frequency caused by changes in the structure temperature. Our design represents an advanced accelerating structure with the optimum SCS properties coexisting with the plunger's good tuning properties. (author)

  7. The upper level of control system of electron accelerators

    International Nuclear Information System (INIS)

    Gribov, I.V.; Nedeoglo, F.N.; Shvedunov, I.V.

    2005-01-01

    The upper level software of a three-level control system that supports several electron accelerators is described. This software operates in the Linux and RTLinux (Real Time Linux) environment. The object information model functions on the basis of a parametric description supported by the SQLite Data Base Management System. The Javascript sublanguage is used for script forming, and the Qt Designer application is used to construct the user interface [ru

  8. Controller for control of pulsed electron linear accelerator

    International Nuclear Information System (INIS)

    Bryazgin, A.A.; Faktorovich, B.L.

    1995-01-01

    The controller is based on the K1816VE31 microprocessor and contains 22-channel integrating 10-digital two-wire analog-to-digital converter, 8-channel 12-digit digital-to-analog converter, 24-digit output register, 16-digit input register pulse generator in the range of 0.5 - 50 Hz with the regulation step of 0.05 Hz and delayed pulse generator. The controller is used for pulsed electron linear accelerator control and is reduced to regulation of the electron beam pulse repetition rate and beam energy. 1 ref., 1 fig

  9. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Matlis, N. H.; Bakeman, M.; Geddes, C. G. R.; Gonsalves, T.; Lin, C.; Nakamura, K.; Osterhoff, J.; Plateau, G. R.; Schroeder, C. B.; Shiraishi, S.; Sokollik, T.; van Tilborg, J.; Toth, Cs.; Leemans, W. P.

    2010-06-01

    We present an overview of diagnostic techniques for measuring key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultaneous diagnostics which are necessary for the full characterization of the ultrashort, but highly-variable electron bunches from LPAs.

  10. 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)

  11. 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)

  12. Observation of 690 MV m-1 Electron Accelerating Gradient with a Laser-Driven Dielectric Microstructure

    International Nuclear Information System (INIS)

    Wootton, K. P.; Wu, Z.; Cowan, B. M.; Hanuka, A.; Makasyuk, I. V.; Peralta, E. A.; Soong, K.; Byer, R. L.; England, R. J.

    2016-01-01

    Acceleration of electrons using laser-driven dielectric microstructures is a promising technology for the miniaturization of particle accelerators. In this work, experimental results are presented of relativistic electron acceleration with 690±100 MVm -1 gradient. This is a record-high accelerating gradient for a dielectric microstructure accelerator, nearly doubling the previous record gradient. To reach higher acceleration gradients the present experiment employs 90 fs duration laser pulses.

  13. Electrostatic accelerator producing high voltage for use with free electron laser

    International Nuclear Information System (INIS)

    Etievant, C.; Roche, M.

    1993-01-01

    The electrostatic accelerator has an acceleration column and a high tension terminal situated at the top of the column and an electric charge transport system. The transport system has a high frequency accelerator. It acts, for example, as a high frequency electron accelerator providing a beam of electrons, with a system for transferring the electrons from the beam to the high voltage terminal. The accelerator may have coaxial cylindrical cavities with a high frequency source providing resonance within the cavity

  14. The applications of electron accelerator. Liquid, thin film and gases

    International Nuclear Information System (INIS)

    Khairul Zaman Hj Mohd Dahlan; Kamaruddin Hashim; Zulkafli Ghazali

    2004-01-01

    As indicated by the results of this study, low energy electron beam accelerator of 200 keV to 500 keV can be utilized to irradiate thin hydrogel film in the range of 60 to 500 μm thickness. However, the industrial applications of this technology will depend on its applications. For thin films, cosmetic use such as faced mask is possible. The production of sago hydrogel for cosmetic used is in the process of commercialization in Malaysia. As for electron beam treatment of industrial wastewater in particular the effluent from the textile industry is still at infancy. Further work is necessary in order to have a base line data before the commercialization is taken place. Malaysia has also embarked on the electron beam treatment of flue gases and has completed the semi-pilot scale study by using 1.0 MeV electron accelerator voltage and 400 cum flue gas generated from diesel generator. This study was conducted together with the TNB Research, the research institute belongs to the electrical power company in Malaysia. For technology transfer and commercialization, MINT is planned to promote this technology to Independent Power Producers (IPP) in Malaysia. (author)

  15. Electron Beam Charge Diagnostics for Laser Plasma Accelerators

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-27

    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{sup 2} and 0.4 pC/(ps mm{sup 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.

  16. Secondary Electron Emission Yields from PEP-II Accelerator Materials

    International Nuclear Information System (INIS)

    Kirby, Robert E.

    2000-01-01

    The PEP-II B-Factory at SLAC operates with aluminum alloy and copper vacuum chambers, having design positron and electron beam currents of 2 and 1 A, respectively. Titanium nitride coating of the aluminum vacuum chamber in the arcs of the positron ring is needed in order to reduce undesirable electron-cloud effects. The total secondary electron emission yield of TiN-coated aluminum alloy has been measured after samples of beam chamber material were exposed to air and again after electron-beam bombardment, as a function of incident electron beam angle and energy. The results may be used to simulate and better understand electron-cloud effects under actual operating conditions. We also present yield measurements for other accelerator materials because new surface effects are expected to arise as beam currents increase. Copper, in particular, is growing in popularity for its good thermal conductivity and self-radiation-shielding properties. The effect of electron bombardment, ''conditioning'', on the yield of TiN and copper is shown

  17. 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.

  18. An energy recovery electron accelerator for DIS at the LHC

    CERN Document Server

    Schulte, Daniel; Jensen, Erk; Valloni, Alessandra; Zimmermann, Frank; Klein, Max

    2014-01-01

    The Large Hadron Electron Collider (LHeC) is a proposed faci lity which will exploit the LHC beams for electron–proton/nucleus scattering, using a new 60 GeV electron accelerator. Following the release of its detailed conceptual design report last ye ar, the configuration of a linac with racetrack shape has been chosen for its default design. Furt her work has been pursued in order to adapt the electron and high luminosity beam optics, to desig n an LHeC Test Facility at CERN and to maximise the ep luminosity to achieve values close to 10 34 cm − 2 s − 1 as is desirable for precision Higgs physics with the LHeC. The talk presents an overview on the design, recent activities and an outlook for further developments

  19. Conceptual design of industrial free electron laser using superconducting accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Saldin, E.L.; Schneidmiller, E.A.; Ulyanov, Yu.N. [Automatic Systems Corporation, Samara (Russian Federation)] [and others

    1995-12-31

    Paper presents conceptual design of free electron laser (FEL) complex for industrial applications. The FEL complex consists of three. FEL oscillators with the optical output spanning the infrared (IR) and ultraviolet (UV) wave-lengths ({lambda} = 0.3...20 {mu}m) and with the average output power 10 - 20 kW. The driving beam for the FELs is produced by a superconducting accelerator. The electron beam is transported to the FELs via three beam lines (125 MeV and 2 x 250 MeV). Peculiar feature of the proposed complex is a high efficiency of the. FEL oscillators, up to 20 %. This becomes possible due to the use of quasi-continuous electron beam and the use of the time-dependent undulator tapering.

  20. Ponderomotive Acceleration of Hot Electrons in Tenuous Plasmas

    International Nuclear Information System (INIS)

    Geyko, V.I.; Fraiman, G.M.; Dodin, I.Y.; Fisch, N.J.

    2009-01-01

    The oscillation-center Hamiltonian is derived for a relativistic electron injected with an arbitrary momentum in a linearly polarized laser pulse propagating in tenuous plasma, assuming that the pulse length is smaller than the plasma wavelength. For hot electrons generated at collisions with ions under intense laser drive, multiple regimes of ponderomotive acceleration are identified and the laser dispersion is shown to affect the process at plasma densities down to 10 17 cm -3 . Assuming a/γ g 0 ∼ g , where a is the normalized laser field, and γ g is the group velocity Lorentz factor. Yet γ ∼ Γ is attained within a wide range of initial conditions; hence a cutoff in the hot electron distribution is predicted

  1. Final Report: Conceptual Design of an Electron Accelerator for Bio-Solid Waste Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Charles [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-09-20

    Several studies have identified electron beam (EB) irradiation of municipal wastewater and bio-solids as an effective and promising approach to the environmental remediation of the enormous quantities of human waste created by a growing world-wide population and increased urbanization. However, despite the technical success of experimental and pilot programs over the last several decades, the technique is still not in commercial use anywhere in the world. In addition, the report also identifies the need for “Financial and infrastructure participation from a utility for demonstration project” and “Education and awareness of safety of utilizing electron beam technology” as two additional roadblocks preventing technology adoption of EB treatment for bio-solids. In this concept design, we begin to address these barriers by working with Metropolitan Water Reclamation District of Greater Chicago (MWRD) and by the applying the latest accelerator technologies developed at Fermilab and within the DOE Office of Science laboratory complex.

  2. Transport and acceleration of low-emittance electron beams

    International Nuclear Information System (INIS)

    Henke, H.

    1989-01-01

    Linear accelerators for colliders and for free-electron lasers require beams with both high brightness and low emittance. Their transport and acceleration is limited by single-particle effects originating from injection jitter, from the unavoidable position jitter of components, and from chromaticity. Collective phenomena, essentially due to wake fields acting within the bunch, are most severe in the case of high-frequency structures, i.e. a small aperture. Whilst, in the past, the transverse wake-field effects were believed to be most serious, we know that they can even be beneficial when inducing a corresponding spread in betatron oscillation either by an energy spread along the bunch or by an RF focusing system acting on the bunch scale. This paper evaluates the different effects by simple analytical means after making use of the smooth focusing approximation and the two-particle model. Numerical simulation results are used for verification. 14 refs., 6 figs., 2 tabs

  3. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B. [Particle Beam Physics Laboratory, UCLA, Los Angeles, CA 90095 (United States); Bruhwiler, David L. [RadiaSoft LLC, Boulder, CO 80304 (United States); RadiaBeam Technologies LLC (United States); Smith, Jonathan [Tech-X UK Ltd, Daresbury, Cheshire WA4 4FS (United Kingdom); Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G. [Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Hidding, Bernhard [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical “plasma torch” distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  4. 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

  5. Joule heating and runaway electron acceleration in a solar flare

    Science.gov (United States)

    Holman, Gordon D.; Kundu, Mukul R.; Kane, Sharad R.

    1989-01-01

    The hard and soft x ray and microwave emissions from a solar flare (May 14, 1980) were analyzed and interpreted in terms of Joule heating and runaway electron acceleration in one or more current sheets. It is found that all three emissions can be generated with sub-Dreicer electric fields. The soft x ray emitting plasma can only be heated by a single current sheet if the resistivity in the sheet is well above the classical, collisional resistivity of 10(exp 7) K, 10(exp 11)/cu cm plasma. If the hard x ray emission is from thermal electrons, anomalous resistivity or densities exceeding 3 x 10(exp 12)/cu cm are required. If the hard x ray emission is from nonthermal electrons, the emissions can be produced with classical resistivity in the current sheets if the heating rate is approximately 4 times greater than that deduced from the soft x ray data (with a density of 10(exp 10)/cu cm in the soft x ray emitting region), if there are at least 10(exp 4) current sheets, and if the plasma properties in the sheets are characteristic of the superhot plasma observed in some flares by Lin et al., and with Hinotori. Most of the released energy goes directly into bulk heating, rather than accelerated particles.

  6. Electron beam welding of high-purity copper accelerator cells

    International Nuclear Information System (INIS)

    Delis, K.; Haas, H.; Schlebusch, P.; Sigismund, E.

    1986-01-01

    The operating conditions of accelerator cells require high thermal conductivity, low gas release in the ultrahigh vacuum, low content of low-melting metals and an extremely good surface quality. In order to meet these requirements, high-purity copper (OFHC, Grade 1, according to ASTM B 170-82 and extra specifications) is used as structural material. The prefabricated components of the accelerator cells (noses, jackets, flanges) are joined by electron beam welding, the weld seam being assessed on the basis of the same criteria as the base material. The welding procedures required depend, first, on the material and, secondly, on the geometries involved. Therefore experimental welds were made first on standardized specimens in order to study the behaviour of the material during electron beam welding and the influence of parameter variations. The welded joints of the cell design were planned on the basis of these results. Seam configuration, welding procedures and the parameters were optimized on components of original geometry. The experiments have shown that high-quality joints of this grade of copper can be produced by the electron beam welding process, if careful planning and preparation of the seams and adequate containment of the welding pool are assured. (orig.)

  7. Thin Film Coatings for Suppressing Electron Multipacting in Particle Accelerators

    CERN Document Server

    Costa Pinto, P; Chiggiato, P; Neupert, H; Shaposhnikova, E N; Taborelli, M; Vollenberg, W; Yin Vallgren, C

    2011-01-01

    Thin film coatings are an effective way for suppressing electron multipacting in particle accelerators. For bakeable beam pipes, the TiZrV Non Evaporable Getter (NEG) developed at CERN can provide a Secondary Electron Yield (SEY) of 1.1 after activation at 180oC (24h). The coating process was implemented in large scale to coat the long straight sections and the experimental beam pipes for the Large Hadron Collider (LHC). For non bakeable beam pipes, as those of the Super Proton Synchrotron (SPS), CERN started a campaign to develop a coating having a low SEY without need of in situ heating. Magnetron sputtered carbon thin films have shown SEY of 1 with marginal deterioration when exposed in air for months. This material is now being tested in both laboratory and accelerator environment. At CERN’s SPS, tests with electron cloud monitors attached to carbon coated chambers show no degradation of the coating after two years of operation interleaved with a total of 3 months of air exposure during shutdown periods...

  8. Design of a self-focusing linear electron accelerator

    International Nuclear Information System (INIS)

    Hddab, S.

    1983-06-01

    In this report we tackle the principal physical and technical problems related to the design of a self-focusing linear electron accelerator. The study of the dynamic phenomena occurring at the entrance to the first resonant cell allows us, by an adequate choice of the longitudinal height of this cell, to avoid the use of an external magnetic focusing coil. Optimization of the ultra high frequency properties of the resonant structure has been achieved by polishing the internal surfaces of the cavities, by adapting a new brazing technique and optimizing the geometry of the cells. A simulation code has been adapted to an interactive use on microcomputer [fr

  9. A high current, short pulse electron source for wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  10. A high current, short pulse electron source for wakefield accelerators

    International Nuclear Information System (INIS)

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed

  11. High power electron beam accelerators for gas laser excitation

    International Nuclear Information System (INIS)

    Kelly, J.G.; Martin, T.H.; Halbleib, J.A.

    1976-06-01

    A preliminary parameter investigation has been used to determine a possible design of a high-power, relativistic electron beam, transversely excited laser. Based on considerations of present and developing pulsed power technology, broad area diode physics and projected laser requirements, an exciter is proposed consisting of a Marx generator, pulse shaping transmission lines, radially converging ring diodes and a laser chamber. The accelerator should be able to deliver approximately 20 kJ of electron energy at 1 MeV to the 10 4 cm 2 cylindrical surface of a laser chamber 1 m long and 0.3 m in diameter in 24 ns with very small azimuthal asymmetry and uniform radial deposition

  12. Uranium target for electron accelerator based neutron source for BNCT

    International Nuclear Information System (INIS)

    Tonchev, A.P.; Harmon, F.; Collens, T.J.; Kennedy, K.; Sabourov, A.; Harker, Y.D.; Nigg, D.W.; Jones, J.L.

    2001-01-01

    Calculations of the epithermal-neutron yield of photoneutrons from a uranium-beryllium converter using a 27 MeV electron linear accelerator have been investigated. In this concept, relativistic electron beams from a 30 MeV LINAC impinge upon a small uranium sphere surrounded by a cylindrical tank of circulating heavy water (D 2 O) nested in a beryllium cube. The photo-fission neutron spectrum from the uranium sphere is thermalized in deuterium and beryllium, filtered and moderated in special material (AlF 3 /Al/LiF), and directed to the patient. The results of these calculations demonstrate that photoneutron devices could offer a promising alternative to nuclear reactors for the production of epithermal neutrons for Neutron Capture Therapy. The predicted parameter for the epithermal flux is more than 10 8 n.cm -2 .mA -1

  13. Longitudinal Jitter Analysis of a Linear Accelerator Electron Gun

    Directory of Open Access Journals (Sweden)

    MingShan Liu

    2016-11-01

    Full Text Available We present measurements and analysis of the longitudinal timing jitter of a Beijing Electron Positron Collider (BEPCII linear accelerator electron gun. We simulated the longitudinal jitter effect of the gun using PARMELA to evaluate beam performance, including: beam profile, average energy, energy spread, and XY emittances. The maximum percentage difference of the beam parameters is calculated to be 100%, 13.27%, 42.24% and 65.01%, 86.81%, respectively. Due to this, the bunching efficiency is reduced to 54%. However, the longitudinal phase difference of the reference particle was 9.89°. The simulation results are in agreement with tests and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

  14. Investigation of123I production using electron accelerator.

    Science.gov (United States)

    Avetisyan, Albert; Avagyan, Robert; Dallakyan, Ruben; Avdalyan, Gohar; Dobrovolsky, Nikolay; Gavalyan, Vasak; Kerobyan, Ivetta; Harutyunyan, Gevorg

    2017-04-01

    The possibility of 123 I isotope production with the help of the high-intensity bremsstrahlung photons produced by the electron beam of the LUE50 linear electron accelerator at the A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute [YerPhI]) is considered. The production method has been established and shown to be successful. The 124 Xe(γ,n) 123 Xe→ 123 I nuclear reaction has been investigated and the cross-section was calculated by nuclear codes TALYS 1.6 and EMPIRE 3.2. The optimum parameter of the thickness of the target was determined by GEANT4 code. For the normalized yield of 123 I, the value of 143Bq/(mg·μA·h) has been achieved. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Investigation of 123I production using electron accelerator

    International Nuclear Information System (INIS)

    Avetisyan, Albert; Avagyan, Robert; Dallakyan, Ruben; Avdalyan, Gohar; Dobrovolsky, Nikolay; Gavalyan, Vasak; Kerobyan, Ivetta; Harutyunyan, Gevorg

    2017-01-01

    The possibility of 123 I isotope production with the help of the high-intensity bremsstrahlung photons produced by the electron beam of the LUE50 linear electron accelerator at the A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute [YerPhI]) is considered. The production method has been established and shown to be successful. The 124 Xe(γ,n) 123 Xe → 123 I nuclear reaction has been investigated and the cross-section was calculated by nuclear codes TALYS 1.6 and EMPIRE 3.2. The optimum parameter of the thickness of the target was determined by GEANT4 code. For the normalized yield of 123 I, the value of 143 Bq/(mg·μA·h) has been achieved.

  16. Electron Acceleration by a Laser Pulse in a Plasma

    Science.gov (United States)

    Startsev, E. A.; McKinstrie, C. J.

    1996-11-01

    The motion of a charged particle in an electromagnetic field is a well-known paradigm of physics. Suppose that the field is associated with a laser pulse of finite extent propagating in a vacuum. As the pulse overtakes the particle, the particle gains energy and momentum. However, the oscillatory energy of the particle is wasted, and it is difficult to extract the particle from the pulse. We have found an exact analytic solution for the motion of an electron under the influence of a circularly polarized laser pulse in a plasma. This solution shows that a pre-accelerated electron can be accelerated efficiently and extracted easily. Although the pulse tends to generate a plasma wake, to which it loses energy, one can eliminate the wake by choosing the duration of the pulse judiciously. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

  17. 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...

  18. Atomic Physics with Accelerators: Projectile Electron Spectroscopy (APAPES)

    International Nuclear Information System (INIS)

    Madesis, I; Dimitriou, A; Zouros, T J M; Laoutaris, A; Lagoyannis, A; Axiotis, M; Mertzimekis, T; Andrianis, M; Harissopulos, S; Benis, E P; Sulik, B; Valastyán, I

    2015-01-01

    The new research initiative APAPES (http://apapes.physics.uoc.gr/) has already established a new experimental station with a beam line dedicated for atomic collisions physics research, at the 5 MV TANDEM accelerator of the National Research Centre ''Demokritos'' in Athens, Greece. A complete zero-degree Auger projectile spectroscopy (ZAPS) apparatus has been put together to perform high resolution studies of electrons emitted in ion-atom collisions. A single stage hemispherical spectrometer with a 2-dimensional Position Sensitive Detector (PSD) combined with a doubly-differentially pumped gas target will be used to perform a systematic isoelectronic investigation of K-Auger spectra emitted from collisions of preexcited and ground state He-like ions with gas targets using novel techniques. Our intention is to provide a more thorough understanding of cascade feeding of the 1s2s2p 4 P metastable states produced by electron capture in collisions of He-like ions with gas targets and further elucidate their role in the non-statistical production of excited three-electron 1s2s2p states by electron capture, recently a field of conflicting interpretations awaiting further resolution. At the moment, the apparatus is being completed and the spectrometer will soon be fully operational. Here we present the project progress and the recent high resolution spectrum obtained in collisions of 12 MeV C 4+ on a Neon gas target

  19. Acceleration and Focusing of Electrons and Positrons Using a 30 GeV Drive Beam

    International Nuclear Information System (INIS)

    Hogan, Mark J

    2003-01-01

    A series of plasma wakefield acceleration (PWFA) experiments are being conducted with a 30 GeV drive beam from the Stanford Linear Accelerator Center (SLAC). These experiments continue to address the application of meter-scale plasmas to focus and accelerate electrons and positrons in the context of future applications to high-energy accelerators

  20. 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

  1. Workshop on Electron-Cloud Simulations for Proton and Positron Beams (ECLOUD'02) organized by the SL Accelerator Physics Group at CERN.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    This workshop was organized by the SL Accelerator Physics group at CERN from 15 to 18 April 2002. More than 60 participants from 17 institutes reflect the great worldwide interest in the electron-cloud phenomenon, which presently limits the performance of several storage rings and has become a concern for the LHC.

  2. Matching beams on photon/electron linear accelerators

    International Nuclear Information System (INIS)

    Oliver, L.; Vial, P.; Hunt, P.

    2004-01-01

    Full text: There are a number of obvious reasons to match megavoltage X-ray and electron beams for clinical purposes. If two dual-purpose X-ray/electron linear accelerators are of the same design and manufacturer, then this might be possible. The issue is however whether the beams can be matched sufficiently close to be considered the same for patient treatments and planning data for dose calculation purposes. If successfully achieved, there are significant advantages in reduced commissioning time, less work in planning and flexibility in the treatment of patients between the two treatment machines. We have investigated matching a new Varian Clinac 21EX with our 1993 Varian Clinac 2100 C/D. A Varian Clinac 1800 was the first linear accelerator installed at RNSH in 1987. When the Clinac 2100 C/D was installed in 1993, we attempted to match all the X-ray and electron beams with the original Clinac 1800 physical data. The X-ray beam characteristics were satisfactory but the electron beams were not sufficiently compatible for planning or patient treatment purposes. A different designed scattering foil and electron applicator were the cause of the different electron beam physical characteristics between the two models. In replacing the Clinac 1800 with the Clinac 21EX, we have used the original 1993 data of the Clinac 2100 C/D as the gold standard to aim for. Initial measurements during acceptance tests showed that all beams satisfied the manufacturer's specification. The energy was then matched to the existing clinical physics data by adjusting the bending magnet power supply and re-tuning the accelerator. This involved matching % depth dose and the corresponding ratio of 10 and 20 cm % depth dose ratio for 6MV and 18 MV X-ray beams. For 6, 9, 12, 16 and 20 MeV electron beams the normal physical parameters of depth of maximum (R max ), the practical range (R p ), the depth of 50% (R 50 ), the slope (G), the average energy at the surface (E 0 ) and the % photon

  3. Electron acceleration in the heart of the Van Allen radiation belts.

    Science.gov (United States)

    Reeves, G D; Spence, H E; Henderson, M G; Morley, S K; Friedel, R H W; Funsten, H O; Baker, D N; Kanekal, S G; Blake, J B; Fennell, J F; Claudepierre, S G; Thorne, R M; Turner, D L; Kletzing, C A; Kurth, W S; Larsen, B A; Niehof, J T

    2013-08-30

    The Van Allen radiation belts contain ultrarelativistic electrons trapped in Earth's magnetic field. Since their discovery in 1958, a fundamental unanswered question has been how electrons can be accelerated to such high energies. Two classes of processes have been proposed: transport and acceleration of electrons from a source population located outside the radiation belts (radial acceleration) or acceleration of lower-energy electrons to relativistic energies in situ in the heart of the radiation belts (local acceleration). We report measurements from NASA's Van Allen Radiation Belt Storm Probes that clearly distinguish between the two types of acceleration. The observed radial profiles of phase space density are characteristic of local acceleration in the heart of the radiation belts and are inconsistent with a predominantly radial acceleration process.

  4. High power pulsed/microwave technologies for electron accelerators vis a vis 10MeV, 10kW electron LINAC for food irradiation at CAT

    International Nuclear Information System (INIS)

    Shrivastava, Purushottam; Mulchandani, J.; Mohania, P.; Baxy, D.; Wanmode, Y.; Hannurkar, P.R.

    2005-01-01

    Use of electron accelerators for irradiation of food items is gathering momentum in India. The various technologies for powering the electron LINAC were needed to be developed in the country due to embargo situations as well as reservations of the developers worldwide to share the information related to this development. Centre for Advanced Technology, CAT, Indore, is engaged in the development of particle accelerators for medical industrial and scientific applications. Amongst other electron accelerators developed in CAT, a 10MeV, 10kW LINAC for irradiation of food items has been commissioned and tested for full rated 10kW beam power. The high power pulsed microwave driver for the LINAC was designed, developed and commissioned with full indigenous efforts, and is right now operational at CAT. It consists of a 6MW, 25kW S-band pulsed klystron, 15MW peak power pulse modulator system for the klystron, microwave driver amplifier chain, stabilized generator, protection and control electronics, waveguide system to handle the high peak and average power, gun modulator electronics, grid electronics etc. The present paper highlights various technologies like the pulsed power systems and components, microwave circuits and systems etc. Also the performance results of the high power microwave driver for the 10MeV LINAC at CAT are discussed. Future strategies for developing the state of art technologies are highlighted. (author)

  5. Latest Diagnostic Electronics Development for the PROSCAN Proton Accelerator

    International Nuclear Information System (INIS)

    Duperrex, P.A.; Frei, U.; Gamma, G.; Mueller, U.; Rezzonico, L.

    2004-01-01

    New VME-based diagnostic electronics are being developed for PROSCAN, a proton accelerator for medical application presently under construction at PSI. One new development is a VME-based multi-channel logarithmic amplifier for converting current to voltage (LogIV). The LogIV boards are used for measuring current from the multiple wire (harp) profile monitors. The LogIV calibration method, current dependant bandwidth and temperature stability are presented. Another development is a BPM front end, based on the newest digital receiver techniques. Features of this new system are the remote control of the preamplifier stage and the continuous monitoring of each individual signal overall gain. Characteristics of the developed prototype are given

  6. Accelerating electron tomography reconstruction algorithm ICON with GPU.

    Science.gov (United States)

    Chen, Yu; Wang, Zihao; Zhang, Jingrong; Li, Lun; Wan, Xiaohua; Sun, Fei; Zhang, Fa

    2017-01-01

    Electron tomography (ET) plays an important role in studying in situ cell ultrastructure in three-dimensional space. Due to limited tilt angles, ET reconstruction always suffers from the "missing wedge" problem. With a validation procedure, iterative compressed-sensing optimized NUFFT reconstruction (ICON) demonstrates its power in the restoration of validated missing information for low SNR biological ET dataset. However, the huge computational demand has become a major problem for the application of ICON. In this work, we analyzed the framework of ICON and classified the operations of major steps of ICON reconstruction into three types. Accordingly, we designed parallel strategies and implemented them on graphics processing units (GPU) to generate a parallel program ICON-GPU. With high accuracy, ICON-GPU has a great acceleration compared to its CPU version, up to 83.7×, greatly relieving ICON's dependence on computing resource.

  7. Radiation processing of liquid with low energy electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-02-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

  8. Radiation processing of liquid with low energy electron accelerator

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2003-01-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

  9. 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

  10. Electron acceleration in the Van Allen radiation belts by fast magnetosonic waves

    OpenAIRE

    Horne, Richard B.; Thorne, Richard M.; Glauert, Sarah A.; Meredith, Nigel P.; Pokhotelov, Dimitry; Santolik, Ondrej

    2007-01-01

    Local acceleration is required to explain electron flux increases in the outer Van Allen radiation belt during magnetic storms. Here we show that fast magnetosonic waves, detected by Cluster 3, can accelerate electrons between ∼10 keV and a few MeV inside the outer radiation belt. Acceleration occurs via electron Landau resonance, and not Doppler shifted cyclotron resonance, due to wave propagation almost perpendicular to the ambient magnetic field. Using quasi-linear theory, pitch angle and ...

  11. Subharmonic beam-loading in electron linear accelerators

    International Nuclear Information System (INIS)

    Gallagher, W.J.

    1983-01-01

    The intention of operating an electron linear accelerator subharmonically beam loaded for free electron laser application requires justification of the beam-loaded energy gain equation. The mode of operation typically planned is 5 to 10 nanocoulombs single RF cycle pulses at 25 to 50 nanosecond intervals. This inquiry investigates the details of this sort of beam loading and discusses the performance achievable. Several other investigations of single bunch beam loading have been undertaken, notably at SLAC, where it has been found experimentally that the beam-loading varies directly as the bunch charge and independently of its energy; that investigation also included radiation effects of the wake field and losses owing to parasitic effects of higher order modes. In the case of beam loading where there are multiple pulses transiting at the same time, and spaced far enough apart that significant RF power is introduced between pulses, the energy gain may be calculated by dividing the waveguide into a number of segments, each equal in length to the integral of the interpulse time and the local group velocity. Equations which reveal that the net energy gain in the steady state is the sum of the energy gains in these segments, which compute the initial field intensity, and which calculate the energy gain in the subharmonic case on the basis of the equivalent beam current are presented

  12. Stacked-Bloch-wave electron diffraction simulations using GPU acceleration

    International Nuclear Information System (INIS)

    Pennington, Robert S.; Wang, Feng; Koch, Christoph T.

    2014-01-01

    In this paper, we discuss the advantages for Bloch-wave simulations performed using graphics processing units (GPUs), based on approximating the matrix exponential directly instead of performing a matrix diagonalization. Our direct matrix-exponential algorithm yields a functionally identical electron scattering matrix to that generated with matrix diagonalization. Using the matrix-exponential scaling-and-squaring method with a Padé approximation, direct GPU-based matrix-exponential double-precision calculations are up to 20× faster than CPU-based calculations and up to approximately 70× faster than matrix diagonalization. We compare precision and runtime of scaling and squaring methods with either the Padé approximation or a Taylor expansion. We also discuss the stacked-Bloch-wave method, and show that our stacked-Bloch-wave implementation yields the same electron scattering matrix as traditional Bloch-wave matrix diagonalization. - Highlights: • Bloch-wave and stacked-Bloch-wave calculations can be accelerated with GPUs. • Direct approximation of the matrix exponential can be faster than diagonalization. • GPU-based direct approximation can be ≈70× faster than CPU diagonalization. • Larger matrices benefit more from this approach than smaller ones. • Stacked-Bloch-wave scattering results are functionally identical to diagonalization

  13. Radiation doses inside industrial irradiation installation with linear electron accelerator

    International Nuclear Information System (INIS)

    Lima, Alexandre R.; Pelegrineli, Samuel Q.; Alo, Gabriel F.; Silva, Francisco C.A. Da

    2015-01-01

    Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

  14. Radiation doses inside industrial irradiation installation with linear electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Alexandre R., E-mail: alexandre.lima@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Pelegrineli, Samuel Q.; Alo, Gabriel F., E-mail: samuelfisica@yahoo.com.br, E-mail: gabriel.alo@aceletron.com.br [Aceletron Irradiacao Industrial, Aceletrica Comercio e Representacoes Ltda, Rio de Janeiro, RJ (Brazil); Silva, Francisco C.A. Da, E-mail: dasilva@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

  15. Collection and recycling of electronic scrap: a worldwide overview and comparison with the Brazilian situation.

    Science.gov (United States)

    de Oliveira, Camila Reis; Bernardes, Andréa Moura; Gerbase, Annelise Engel

    2012-08-01

    Recycling and the related issue of sustainable development are increasing in importance around the world. In Brazil, the new National Policy on Solid Wastes has prompted discussion on the future of electronic waste (e-waste). Over the last 10 years, different e-waste collection systems and recycling processes have been applied globally. This paper presents the systems used in different countries and compares the world situation to the current Brazilian reality. To establish a recycling process, it is necessary to organize efficient collection management. The main difficulty associated with the implementation of e-waste recycling processes in Brazil is the collection system, as its efficiency depends not only on the education and cooperation of the people but also on cooperation among industrial waste generators, distributors and the government. Over half a million waste pickers have been reported in Brazil and they are responsible for the success of metal scrap collection in the country. The country also has close to 2400 companies and cooperatives involved in recycling and scrap trading. On the other hand, the collection and recycling of e-waste is still incipient because e-wastes are not seen as valuable in the informal sector. The Brazilian challenge is therefore to organize a system of e-waste management including the informal sector without neglecting environmentally sound management principles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 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.

  17. Linear Electron Accelerators For Radiation Processing. Current Status

    CERN Document Server

    Vorogushin, M F; Fialkovsky, A M; Fomin, L P; Gavrish, Y N; Klinov, A P; Maslennikov, O L; Naumov, S F; Nikolaev, V M; Shchepin, Yu P

    2004-01-01

    NPK LUTS NIIEFA has been developing linear accelerators for industrial applications during about 30 years. More than 150 linear accelerators for different applications have been manufactured by this company and installed in different regions of Russia and abroad. The linear accelerators for radiation sterilization developed in NPK LUTS NIIEFA are reviewed in this report.

  18. Characterisation of electron beams from laser-driven particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2012-12-21

    The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

  19. 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.))

  20. 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

  1. Data acquisition workstation for Oak Ridge Electron Linear Accelerator

    International Nuclear Information System (INIS)

    Todd, J.H.; Rooney, B.D.; Spencer, R.H.; Weston, L.W.

    1993-01-01

    A new multiparameter data acquisition system for the Oak Ridge Electron Linear Accelerator (ORELA) was developed, fabricated and tested. This system uses an IBM PS/2 Model 80-111 personal computer and a data handler with a 2048-word buffer. The buffer can accept data at a rate exceeding one million events per second in bursts of 512 words of 64-bits in length. The acquisition system, limited by software, can acquire data from 1, 2, or 3 digitizers; multiplex up to 4 detectors; read and control up to 16 scalers or registers; and output up to 32 dc logic lines that can be used to control external instrumentation. Software was developed for the OS/2 operating system, supporting multiparameter data storage for up to three million channels. Data can be collected in a background mode to make the computer available for other tasks while collecting data. The system also supports multiparameter biasing and can collect, crunch, and store data at rates of 30,000 events per second, each event containing up to 64-bits of information. A technical manual, ORNL/TM-11454, covering the use of the system has been published

  2. Electron transport with re-acceleration and radiation in the jets of X-ray binaries

    Science.gov (United States)

    Zhang, Jian-Fu; Li, Zhi-Ren; Xiang, Fu-Yuan; Lu, Ju-Fu

    2018-01-01

    This paper studies the acceleration processes of background thermal electrons in X-ray binary jets via turbulent stochastic interactions and shock collisions. By considering turbulent magnetized jets mixed with fluctuating magnetic fields and an ordered large-scale magnetic field, and numerically solving the transport equation along the jet axis, we explore the influence on acceleration efficiency of magnetic turbulence, electron injection, the location of the acceleration region and various cooling mechanisms. The results show the following: (1) Dominant turbulent magnetic fields in the jets are necessary to accelerate background thermal electrons to relativistic energies. (2) The acceleration of electrons depends on the type of magnetohydrodynamic turbulence and turbulence with a hard slope can accelerate electrons more effectively. (3) The effective acceleration region is located at a distance >103Rg away from the central black hole (Rg being the gravitational radius). As a result of acceleration mechanisms competing with various cooling mechanisms, background thermal electrons gain energy and their spectra are broadened beyond the initial distribution to form a thermal-like distribution. (4) The acceleration mechanisms explored in this work can reasonably provide the maximum electron energy required for interpreting high-energy γ-ray observations from microquasars; however, some extreme parameter values are needed for the possible very high-energy γ-ray signals.

  3. 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

  4. Improved electron collimation system design for Elekta linear accelerators.

    Science.gov (United States)

    Pitcher, Garrett M; Hogstrom, Kenneth R; Carver, Robert L

    2017-09-01

    Prototype 10 × 10 and 20 × 20-cm 2 electron collimators were designed for the Elekta Infinity accelerator (MLCi2 treatment head), with the goal of reducing the trimmer weight of excessively heavy current applicators while maintaining acceptable beam flatness (±3% major axes, ±4% diagonals) and IEC leakage dose. Prototype applicators were designed initially using tungsten trimmers of constant thickness (1% electron transmission) and cross-sections with inner and outer edges positioned at 95% and 2% off-axis ratios (OARs), respectively, cast by the upstream collimating component. Despite redefining applicator size at isocenter (not 5 cm upstream) and reducing the energy range from 4-22 to 6-20 MeV, the designed 10 × 10 and 20 × 20-cm 2 applicator trimmers weighed 6.87 and 10.49 kg, respectively, exceeding that of the current applicators (5.52 and 8.36 kg, respectively). Subsequently, five design modifications using analytical and/or Monte Carlo (MC) calculations were applied, reducing trimmer weight while maintaining acceptable in-field flatness and mean leakage dose. Design Modification 1 beveled the outer trimmer edges, taking advantage of only low-energy beams scattering primary electrons sufficiently to reach the outer trimmer edge. Design Modification 2 optimized the upper and middle trimmer distances from isocenter for minimal trimmer weights. Design Modification 3 moved inner trimmer edges inward, reducing trimmer weight. Design Modification 4 determined optimal X-ray jaw positions for each energy. Design Modification 5 adjusted middle and lower trimmer shapes and reduced upper trimmer thickness by 50%. Design Modifications 1→5 reduced trimmer weights from 6.87→5.86→5.52→5.87→5.43→3.73 kg for the 10 × 10-cm 2 applicator and 10.49→9.04→8.62→7.73→7.35→5.09 kg for the 20 × 20-cm 2 applicator. MC simulations confirmed these final designs produced acceptable in-field flatness and met IEC-specified leakage dose at 7, 13, and 20 Me

  5. Low Secondary Electron Yield Carbon Coatings for Electron Cloud Mitigation in Modern Particle Accelerators

    CERN Document Server

    Yin Vallgren, Christina; Taborelli, Mauro

    2011-01-01

    In order to upgrade the Large Hadron Collider (LHC) performance to be oriented towards higher energies and higher intensities in the future, a series of improvements of the existing LHC injectors is planned to take place over the next few years. Electron cloud effects are expected to be enhanced and play a central role in limiting the performance of the machines of the CERN complex. Electron cloud phenomena in beam pipes are based on electron multiplication and can be sufficiently suppressed if the Secondary Electron Yield (SEY) of the surface of the beam pipes is lower than unity. The goal of this work is to find and study a thin film coating with reliably low initial Secondary Electron Yield (SEY), which does not require bake-out or conditioning in situ with photons, is robust again air exposure and can easily be applied in the beam pipes of accelerators. In this work, amorphous carbon (a-C) thin films have been prepared by DC magnetron sputtering for electron cloud mitigation and antimultipactor applicatio...

  6. Transmission electron microscope interfaced with ion accelerators and its application to materials science

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Hiroaki; Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Hojou, Kiichi; Furuno, Shigemi; Tsukamoto, Tetsuo

    1997-03-01

    We have developed the transmission/analytical electron microscope interfaced with two sets of ion accelerators (TEM-Accelerators Facility) at JAERI-Takasaki. The facility is expected to provide quantitative insights into radiation effects, such as damage evolution, irradiation-induced phase transformation and their stability, through in-situ observation and analysis under ion and/or electron irradiation. The TEM-Accelerators Facility and its application to materials research are reviewed. (author)

  7. Dielectric emitter in an injector of a linear induction electron accelerator

    International Nuclear Information System (INIS)

    Tomskikh, O.N.; Furman, Eh.G.

    1991-01-01

    Dielectric emitter in an injector of linear induction electron accelerator is decribed. Principle of operation of a new-type cathode - dielectric emitter - is based on preliminary accumulation of electron charge on the dielectric surface with their subsequent injection. Injector design of linear induction accelerator with dielectric emitter, providing for generation of beam current of 1.5 kA by charging voltage of 29 kV and accelerating voltage of 400 kV is described

  8. 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.

  9. 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

  10. The superconducting 130 MeV electron accelerator at Darmstadt

    International Nuclear Information System (INIS)

    Aab, A.; Alrutz-Ziemssen, K.; Amend, R.; Flasche, D.; Graef, H.D.; Huck, V.; Hummel, K.D.; Knirsch, M.; Lindqvist, F.; Lotz, W.; Richter, A.; Rietdorf, T.; Schaaf, U.; Simrock, S.; Spamer, E.; Stiller, A.; Titze, O.; Weise, H.; Ziegler, W.; Heinrichs, H.; Piel, H.; Pouryamout, J.

    1988-07-01

    Since the superconducting injector linac of the accelerator produced a first beam in August 87 the first cryomodule of the main linac containing another two accelerating structures has been installed and operated. The final concept of the rf control circuits has been developed and two prototype channels were operated successfully in an acceleration test with five superconducting structures. The beam from the injector linac was used routinely for atomic and nuclear physics experiments during the last four months. (orig.)

  11. Electron energy and electron trajectories in an inverse free-electron laser accelerator based on a novel electrostatic wiggler

    Science.gov (United States)

    Nikrah, M.; Jafari, S.

    2016-06-01

    We expand here a theory of a high-gradient laser-excited electron accelerator based on an inverse free-electron laser (inverse-FEL), but with innovations in the structure and design. The electrostatic wiggler used in our scheme, namely termed the Paul wiggler, is generated by segmented cylindrical electrodes with applied oscillatory voltages {{V}\\text{osc}}(t) over {{90}\\circ} segments. The inverse-FEL interaction can be described by the equations that govern the electron motion in the combined fields of both the laser pulse and Paul wiggler field. A numerical study of electron energy and electron trajectories has been made using the fourth-order Runge-Kutta method. The results indicate that the electron attains a considerable energy at short distances in this device. It is found that if the electron has got sufficient suitable wiggler amplitude intensities, it can not only gain higher energy in longer distances, but also can retain it even after the passing of the laser pulse. In addition, the results reveal that the electron energy gains different peaks for different initial axial velocities, so that a suitable small initial axial velocity of e-beam produces substantially high energy gain. With regard to the transverse confinement of the electron beam in a Paul wiggler, there is no applied axial guide magnetic field in this device.

  12. RELATIVISTIC ELECTRON SHOCK DRIFT ACCELERATION IN LOW MACH NUMBER GALAXY CLUSTER SHOCKS

    International Nuclear Information System (INIS)

    Matsukiyo, S.; Ohira, Y.; Yamazaki, R.; Umeda, T.

    2011-01-01

    An extreme case of electron shock drift acceleration (SDA) in low Mach number collisionless shocks is investigated as a plausible mechanism for the initial acceleration of relativistic electrons in large-scale shocks in galaxy clusters, where the upstream plasma temperature is of the order of 10 keV and the degree of magnetization is not too small. One-dimensional electromagnetic full particle simulations reveal that, even when a shock is rather moderate, a part of the thermal incoming electrons are accelerated and reflected through relativistic SDA and form a local non-thermal population just upstream of the shock. The accelerated electrons can self-generate local coherent waves and further be back-scattered toward the shock by those waves. This may be a scenario for the first stage of the electron shock acceleration occurring at the large-scale shocks in galaxy clusters, such as CIZA J2242.8+5301, which have well-defined radio relics.

  13. Induction accelerators and free-electron lasers at LLNL

    International Nuclear Information System (INIS)

    Briggs, R.J.

    1989-01-01

    Linear induction accelerators have been developed to produce pulses of charged particles at voltages exceeding the capabilities of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine. The advent of magnetic pulse power systems makes sustained operation at high repetition rates practical, and high-average-power capability is very likely to open up many new applications of induction machines

  14. Electron Acceleration in Wakefield and Supra-Bubble Regimes by Ultraintense Laser with Asymmetric Pulse

    International Nuclear Information System (INIS)

    Maimaitiaili, Bake; Sayipjamal, Dulat; Aimierding, Aimidula; Xie Baisong

    2011-01-01

    Electron acceleration in plasma driven by circular polarized ultraintense laser with asymmetric pulse are investigated analytically and numerically in terms of oscillation-center Hamiltonian formalism. Studies include wakefield acceleration, which dominates in blow-out or bubble regime and snow-plow acceleration which dominates in supra-bubble regime. By a comparison with each other it is found that snow-plow acceleration has lower acceleration capability. In wakefield acceleration, there exists an obvious optimum pulse asymmetry or/and pulse lengths that leads to the high net energy gain while in snow-plow acceleration it is insensitive to the pulse lengths. Power and linear scaling laws for wakefield and snow-plow acceleration respetively are observed from the net energy gain depending on laser field amplitude. Moreover, there exists also an upper and lower limit on plasma density for an effective acceleration in both of regimes. (physics of gases, plasmas, and electric discharges)

  15. Status of the visible Free-Electron Laser at the Brookhaven Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fisher, A.S.; Friedman, A.; Gallardo, J.; Ingold, G.; Kirk, H.; Kramer, S.; Lin, L.; Rogers, J.T.; Sheehan, J.F.; van Steenbergen, A.; Woodle, M.; Xie, J.; Yu, L.H.; Zhang, R.; Bhowmik, A.

    1991-01-01

    The 500 nm Free-Electron Laser (ATF) of the Brookhaven National Laboratory is reviewed. We present an overview of the ATF, a high-brightness, 50-MeV, electron accelerator and laser complex which is a users' facility for accelerator and beam physics. A number of laser acceleration and FEL experiments are under construction at the ATF. The visible FEL experiment is based on a novel superferric 8.8 mm period undulator. The electron beam parameters, the undulator, the optical resonator, optical and electron beam diagnostics are discussed. The operational status of the experiment is presented. 22 refs., 7 figs

  16. Degradation of naphthalene and fluorene by radiolysis using accelerated electrons

    International Nuclear Information System (INIS)

    Flores de Jesus, I.

    2003-01-01

    The volume of the dangerous wastes in global level is causing the poisoning of planet and all of the ecosystems, degrading the life level of millions of humans and causing serious problems in the public health. Since a years ago the volumes of organic effluents generated by the few industry and small populations were so tiny that a natural debugger process in a time and space delimited, acquiring again their natural characteristics and they could be used again. Nowadays these wastes are so numerous and precise in some cases that the capacity of natural purification in the receiving channel is not enough, in addition to the difficulty to treat them in conventional processes, this leads to the decrease in the water's quality making impossible its future use and causing with this a serious ecological problem. This fact has motivated the development of measures that tend to the conservation of the environment and in consequence, the development of debugger technologies with no generation of sub products that often are more dangerous than the originals, due to the previous thing, the treatment by means of radiation of the water is impelled since is a method that allows to degrade or to eliminate in simultaneous form pathogenic microorganisms and organic substances. The radiation by means of electrons beams is a method of advanced treatment who allows to degrade organic compounds, transforming them in compounds with less molecular weight, and in the best of the cases until its oxidation to carbon dioxide and water. In the present thesis the objective is the study of naphthalene and fluorene degradation by means of radiation with electron beams, establishing the operating conditions of the accelerator of Pelletron type. This research is supported by the Instituto Nacional de Investigaciones Nucleares, of a joint way with a series of antecedents in this subject, established in previous research with respect to the treatment of residual waters in a great scale, giving

  17. Data acquisition system for the Pelletron electron accelerator

    International Nuclear Information System (INIS)

    Flores E, O.

    1997-01-01

    In this work, a system is developed that allows to know and view of immediate manner the conditions occurred during the operation of the Pelletron. This is carried out by means of the design of a data acquisition system which displays in graphic form, in the screen of a computer, the operation conditions like pressure of the tank, current of the electron beam, voltage in the inductors of the elctrostatic generator, level of produced radiation, etc., all of this parameters determine the behavior of the accelerator. The hardware of the system includes the design and construction of conditioning and transmission circuits used to send the information to an interface board that allows th communication between the analog world and the computer. In this case, the utilized board is the AT-MIO-16L-25, that is a high-performance multifunction analog, digital and timing input/output (I/O) board for the IBM PC/AT and compatibles. The software implicates the design of the necessary programs to manipulate the interface board, for the processing and presentation of information in the screen of the computer and also for the storage of the acquired data in a permanent medium. In this case, a relatively new tool, known like Virtual instrumentation is utilized. Concretely, the LabVIEW programming software package is used (Laboratory Virtual Instrument Engineering Workbench), which is designed for applications in instrumentation and control. This programming package gives the necessary elements for the analysis and processing of the acquired data. The system is developed in base to the requirements done for the users and designers of the Pelletron. (Author)

  18. 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.

  19. Investigation of STRAUS-2 pulsed electron accelerator characteristics

    International Nuclear Information System (INIS)

    Gordeev, V.S.; Myskov, G.A.; Filippov, V.O.

    1999-01-01

    A lot of experimental data was obtained at the STRAUS-2 accelerator.This data were used for verifying and testing of simulation methods,algorithms and codes applied for calculations in a designing process of similar type facilities as the STRAUS-2 accelerator

  20. The control computer for the Chalk River electron test accelerator

    International Nuclear Information System (INIS)

    McMichael, G.E.; Fraser, J.S.; McKeown, J.

    1978-02-01

    A versatile control and data acquisition system has been developed for a modest-sized linear accelerator using mainly process I/O hardware and software. This report describes the evolution of the present system since 1972, the modifications needed to satisfy the changing requirements of the various accelerator physics experiments and the limitations of such a system in process control. (author)

  1. Bacterial effect of accelerated electrons on several pathogens

    International Nuclear Information System (INIS)

    Butaev, M.K.; Bulkhanov, R.U.; Ryasnyanskii, I.V.; Mirzaev, B.Sh.; Safarov, A.N.; Suleymanov, R.D.

    2006-01-01

    colibacterillesis and salmonellosis of calves' were developed in RIVU. By widening the application field of developed radiation biotechnology the 'Polyvalent vaccine against pasteurellesis, salmonellosis and colibacterillesis of farm animals' was created in recent years. The mentioned radio vaccines were successfully tested in laboratory and working environment and are widely used in veterinary practice in the farms of the Republic of Uzbekistan [3].For further broadening of the possibility to use the radiation biotechnology and to enrich the native arsenal of veterinary bio medication, it is presently planned to conduct large-scale research on the use of accelerated electrons (AE) to obtain in perspective new preventive materials. Several results of the beginning stage of this research are given in the present report.The suspensions of pathogenic strains of pasteurellesis, salmonellosis and Escherichia Coli strains were exposed to irradiation by accelerated electrons of microtron MT-22C. Taking into account the slightly higher resistance of bacteria against irradiation by accelerated electrons as compared to gamma-irradiation, the doses from 400 to 1100 kRad were used. At this, the special attention was paid to control the distribution of linear density of the current in scanning of AE beam, the distribution of linear density of the current in perpendicular scanning of AE beam and the value of absorbed dose. The studies showed that at AE irradiation by 400 kRad dose the bacterial survival rate is about 10 %, at 500 kRad-2-3 %, 600 kRad- less than 1 %. At the dose of 800 kRad only isolated colonies of bacteria survived. At AE irradiation by 900 kRad- 1.1 MRad dose, there was no increase the growth of bacteria's number. Since these data were obtained at the multiple repetition of results, it can be supposed that the minimal absolute devitalizing AE irradiation dose of bacteria lies in the region 0.9-1.0 MRad. At this, some inter-species and even intra species peculiarities in the

  2. 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

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

    International Nuclear Information System (INIS)

    Breuer, John

    2013-01-01

    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

  4. On the Possibility of Accelerating Positron on an Electron Wake at SABER

    International Nuclear Information System (INIS)

    Ischebeck, R.; Joshi, C.; Katsouleas, T.C.; Muggli, P.; Wang, X.

    2008-01-01

    A new approach for positron acceleration in non-linear plasma wakefields driven by electron beams is presented. Positrons can be produced by colliding an electron beam with a thin foil target embedded in the plasma. Integration of positron production and acceleration in one stage is realized by a single relativistic, intense electron beam. Simulations with the parameters of the proposed SABER facility [1] at SLAC suggest that this concept could be tested there

  5. Solar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis

    OpenAIRE

    Li, W; Thorne, RM; Bortnik, J; Baker, DN; Reeves, GD; Kanekal, SG; Spence, HE; Green, JC

    2015-01-01

    ©2015. American Geophysical Union. All Rights Reserved. Determining preferential solar wind conditions leading to efficient radiation belt electron acceleration is crucial for predicting radiation belt electron dynamics. Using Van Allen Probes electron observations ( > 1 MeV) from 2012 to 2015, we identify a number of efficient and inefficient acceleration events separately to perform a superposed epoch analysis of the corresponding solar wind parameters and geomagnetic indices. By directly c...

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

    International Nuclear Information System (INIS)

    Friedman, M.

    1989-01-01

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

  7. Laser-driven wakefield electron acceleration and associated radiation sources

    International Nuclear Information System (INIS)

    Davoine, X.

    2009-10-01

    The first part of this research thesis introduces the basic concepts needed for the understanding of the laser-driven wakefield acceleration. It describes the properties of the used laser beams and plasmas, presents some notions about laser-plasma interactions for a better understanding of the physics of laser-driven acceleration. The second part deals with the numerical modelling and the presentation of simulation tools needed for the investigation of laser-induced wakefield acceleration. The last part deals with the optical control of the injection, a technique analogous to the impulsion collision scheme

  8. The state of development of an intense resonance electron-ion accelerator based on Doppler effect

    International Nuclear Information System (INIS)

    Egorov, A.M.; Ivanov, B.I.; Butenko, V.I.; Ognivenko, V.V.; Onishchenko, I.N.; Prishchepov, V.P.

    1996-01-01

    An intense ion accelerator has been proposed and now is being developed in which accelerating and focusing electric fields in a slow wave structure are excited by an intense electron beam using the anomalous and the normal Doppler effects. The results of theoretical studies and computer simulations show the advantage of this acceleration method that will make it possible to obtain acceleration rates of the order of 10 - 100 MeV/m, and ion beam energies and currents of the order of 10-100 MeV, 1-10 A. The project and technical documentation of an experimental accelerating installation were worked out. Currently, the 5 MeV accelerator-injector URAL-5 is in operation; preliminary experiments on a small installation have been carried out; experimental investigations of an accelerating RF resonator model (in 1/2 scaling) are being performed; the accelerating test installation is being manufactured. (author). 1 tab. 12 fig., 6 refs

  9. Observation of 690 MV m-1 Electron Accelerating Gradient with a Laser-Driven Dielectric Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, K.P.; Wu, Z.; /SLAC; Cowan, B.M.; /Tech-X, Boulder; Hanuka, A.; /SLAC /Technion; Makasyuk, I.V.; /SLAC; Peralta, E.A.; Soong, K.; Byer, R.L.; /Stanford U.; England, R.J.; /SLAC

    2016-06-27

    Acceleration of electrons using laser-driven dielectric microstructures is a promising technology for the miniaturization of particle accelerators. In this work, experimental results are presented of relativistic electron acceleration with 690±100 MVm-1 gradient. This is a record-high accelerating gradient for a dielectric microstructure accelerator, nearly doubling the previous record gradient. To reach higher acceleration gradients the present experiment employs 90 fs duration laser pulses.

  10. Novel production techniques of radioisotopes using electron accelerators

    Science.gov (United States)

    Lowe, Daniel Robert

    Non-traditional radioisotope production techniques using a compact, high power linear electron accelerator have been demonstrated and characterized for the production of 18F, 47Sc, 147 Pm, and 99mTc from a variety of target candidates. These isotopes are used extensively in the medical field as diagnostic and therapy radioisotopes, as well as the space industry as RTG's. Primary focus was placed on 99mTc as it constitutes approximately 80% of all diagnostic procedures in the medical community that use radioactive tracers. It was also the prime focus due to recent events at the Chalk River nuclear reactor, which caused global shortages of this isotope a few years ago. A Varian K15 LINAC was first used to show proof of principle in Las Vegas. Various samples were then taken to the Idaho Accelerator Center where they were activated using an electron LINAC capable of electron energies from 4 to 25 MeV at a beam power of approximately 1 kW. Production rates, cross sections, and viability studies were then performed and conducted to assess the effectiveness of the candidate target and the maximum production rate for each radioisotope. Production rates for 18F from lithium fluoride salts were shown to be ideal at 21MeV, namely 1.7 Ci per kg of LiF salt, per kW of beam current, per 10 hour irradiation time. As the typical hospital consumption of 18F is around 500 mCi per day, it is clear that a large amount of 18F can be made from a small (300 gram) sample of LiF salt. However, since there is no current separation process for 18F from 19F, the viability of this technique is limited until a separations technique is developed. Furthermore, the calculated cross section for this reaction is in good agreement with literature, which supports the techniques for the isotopes mentioned below. Production rates for 47Sc from vanadium oxide targets were shown to be a maximum at 25 MeV with a production rate of 2 mCi per day, assuming a 2 kW beam and a 10 kg target. While this

  11. Calculations of beam dynamics in Sandia linear electron accelerators, 1984

    International Nuclear Information System (INIS)

    Poukey, J.W.; Coleman, P.D.

    1985-03-01

    A number of code and analytic studies were made during 1984 which pertain to the Sandia linear accelerators MABE and RADLAC. In this report the authors summarize the important results of the calculations. New results include a better understanding of gap-induced radial oscillations, leakage currents in a typical MABE gas, emittance growth in a beam passing through a series of gaps, some new diocotron results, and the latest diode simulations for both accelerators. 23 references, 30 figures, 1 table

  12. A 400KV multi-functional electron and ion radiation accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Youyi; Wang Xurong; Deng Gulin (Sichuan Univ., Chengdu, SC (China). Inst. of Nuclear Science and Technology)

    In this paper we describe a 400 kV multi-functional electron and positive ion irradiation accelerator based upon a 400 kC Cockcroft-Walton, which was successfully used to accelerate electrons and positive ions with an electron beam current of more than 5 mA. It has a scanning window of 1200 mm in width, a scanning frame of 4500 x 1400 mm. The transmitting speed of the scanning frame is between 0.1-5 m backward and forward, continuously adjustable. The conversion time from accelerating positive ions to electrons is less than twenty minutes, and vice versa. It is proved that this accelerator can meet more requirements in the fields of nuclear physics and electron irradiation applications. (author).

  13. A 400KV multi-functional electron and ion radiation accelerator

    Science.gov (United States)

    Youyi, Zhou; Xurong, Wang; Gulin, Deng

    1993-07-01

    In this paper we describe a 400kV multi-functional electron and positive ion irradiation accelerator based upon a 400kV Cockcroft-Walton, which was successfully used to accelerate electrons and positive ions with electron beam current of more than 5 mA. It has a scanning window of 1200mm in width, a scanning frame of 4500×1400mm. The transmitting speed of the scanning frame is between 0.1-5m backward and forward, continuously adjustable. The conversion time from accelerating positive ions to electrons is less than twenty minutes, and vice versa. It is proved that this accelerator can meet more requirements in the fields of nuclear physics and electron irradiation applications.

  14. A 400KV multi-functional electron and ion radiation accelerator

    International Nuclear Information System (INIS)

    Zhou Youyi; Wang Xurong; Deng Gulin

    1993-01-01

    In this paper we describe a 400 kV multi-functional electron and positive ion irradiation accelerator based upon a 400 kC Cockcroft-Walton, which was successfully used to accelerate electrons and positive ions with an electron beam current of more than 5 mA. It has a scanning window of 1200 mm in width, a scanning frame of 4500 x 1400 mm. The transmitting speed of the scanning frame is between 0.1-5 m backward and forward, continuously adjustable. The conversion time from accelerating positive ions to electrons is less than twenty minutes, and vice versa. It is proved that this accelerator can meet more requirements in the fields of nuclear physics and electron irradiation applications. (author)

  15. Proposed Physics Experiments for Laser-Driven Electron Linear Acceleration in a Dielectric Loaded Vacuum, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Byer, Robert L. [Stanford Univ., CA (United States). Dept. of Applied Physics. Edward L. Ginzton Lab.

    2016-07-08

    This final report summarizes the last three years of research on the development of advanced linear electron accelerators that utilize dielectric wave-guide vacuum channels pumped by high energy laser fields to accelerate beams of electrons.

  16. The application analysis of high energy electron accelerator in food irradiation processing

    International Nuclear Information System (INIS)

    Deng Wenmin; Chen Hao; Feng Lei; Zhang Yaqun; Chen Xun; Li Wenjun; Xiang Chengfen; Pei Ying; Wang Zhidong

    2012-01-01

    Irradiation technology of high energy electron accelerator has been highly concerned in food processing industry with its fast development, especially in the field of food irradiation processing. In this paper, equipment and research situation of high energy electron accelerator were collected, meanwhile, the similarities and differences between high energy electron beam and 60 Co γ-rays were discussed. In order to provide more references of high energy electron beam irradiation, the usages of high energy electron in food irradiation processing was prospected. These information would promote the development of domestic food irradiation industry and give a useful message to irradiation enterprises and researchers. (authors)

  17. 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.

  18. An in situ Comparison of Electron Acceleration at Collisionless Shocks under Differing Upstream Magnetic Field Orientations

    International Nuclear Information System (INIS)

    Masters, A.; Dougherty, M. K.; Sulaiman, A. H.; Stawarz, Ł.; Reville, B.; Sergis, N.; Fujimoto, M.; Burgess, D.; Coates, A. J.

    2017-01-01

    A leading explanation for the origin of Galactic cosmic rays is acceleration at high-Mach number shock waves in the collisionless plasma surrounding young supernova remnants. Evidence for this is provided by multi-wavelength non-thermal emission thought to be associated with ultrarelativistic electrons at these shocks. However, the dependence of the electron acceleration process on the orientation of the upstream magnetic field with respect to the local normal to the shock front (quasi-parallel/quasi-perpendicular) is debated. Cassini spacecraft observations at Saturn’s bow shock have revealed examples of electron acceleration under quasi-perpendicular conditions, and the first in situ evidence of electron acceleration at a quasi-parallel shock. Here we use Cassini data to make the first comparison between energy spectra of locally accelerated electrons under these differing upstream magnetic field regimes. We present data taken during a quasi-perpendicular shock crossing on 2008 March 8 and during a quasi-parallel shock crossing on 2007 February 3, highlighting that both were associated with electron acceleration to at least MeV energies. The magnetic signature of the quasi-perpendicular crossing has a relatively sharp upstream–downstream transition, and energetic electrons were detected close to the transition and immediately downstream. The magnetic transition at the quasi-parallel crossing is less clear, energetic electrons were encountered upstream and downstream, and the electron energy spectrum is harder above ∼100 keV. We discuss whether the acceleration is consistent with diffusive shock acceleration theory in each case, and suggest that the quasi-parallel spectral break is due to an energy-dependent interaction between the electrons and short, large-amplitude magnetic structures.

  19. An in situ Comparison of Electron Acceleration at Collisionless Shocks under Differing Upstream Magnetic Field Orientations

    Energy Technology Data Exchange (ETDEWEB)

    Masters, A.; Dougherty, M. K. [The Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Sulaiman, A. H. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Stawarz, Ł. [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244 Krakow (Poland); Reville, B. [School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Sergis, N. [Office of Space Research and Technology, Academy of Athens, Soranou Efesiou 4, 11527 Athens (Greece); Fujimoto, M. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Burgess, D. [School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom); Coates, A. J., E-mail: a.masters@imperial.ac.uk [Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom)

    2017-07-10

    A leading explanation for the origin of Galactic cosmic rays is acceleration at high-Mach number shock waves in the collisionless plasma surrounding young supernova remnants. Evidence for this is provided by multi-wavelength non-thermal emission thought to be associated with ultrarelativistic electrons at these shocks. However, the dependence of the electron acceleration process on the orientation of the upstream magnetic field with respect to the local normal to the shock front (quasi-parallel/quasi-perpendicular) is debated. Cassini spacecraft observations at Saturn’s bow shock have revealed examples of electron acceleration under quasi-perpendicular conditions, and the first in situ evidence of electron acceleration at a quasi-parallel shock. Here we use Cassini data to make the first comparison between energy spectra of locally accelerated electrons under these differing upstream magnetic field regimes. We present data taken during a quasi-perpendicular shock crossing on 2008 March 8 and during a quasi-parallel shock crossing on 2007 February 3, highlighting that both were associated with electron acceleration to at least MeV energies. The magnetic signature of the quasi-perpendicular crossing has a relatively sharp upstream–downstream transition, and energetic electrons were detected close to the transition and immediately downstream. The magnetic transition at the quasi-parallel crossing is less clear, energetic electrons were encountered upstream and downstream, and the electron energy spectrum is harder above ∼100 keV. We discuss whether the acceleration is consistent with diffusive shock acceleration theory in each case, and suggest that the quasi-parallel spectral break is due to an energy-dependent interaction between the electrons and short, large-amplitude magnetic structures.

  20. Nicotiana Occidentalis Chloroplast Ultrastructure imaged with Transmission Electron Microscopes Working at Different Accelerating Voltages

    OpenAIRE

    SVIDENSKÁ, Silvie

    2010-01-01

    The main goal of this thesis is to study and compare electron microscopy images of Nicotiana Occidentalis chloroplasts, obtained from two types of transmission electron microscopes,which work with different accelerating voltage of 80kV and 5kV. The two instruments, TEM JEOL 1010 and low voltage electron microscope LVEM5 are employed for experiments. In the first theoretical part, principle of electron microscopy and chloroplast morphology is described. In experimental part, electron microscop...

  1. Power efficiency optimization of disk-loaded waveguide traveling wave structure of electron linear accelerator

    International Nuclear Information System (INIS)

    Yang Jinghe; Li Jinhai; Li Chunguang

    2014-01-01

    Disk-loaded waveguide traveling wave structure (TWS), which is widely used in scientific research and industry, is a vital accelerating structure in electron linear accelerator. The power efficiency is an important parameter for designing TWS, which greatly effects the expenses for the fabrication and commercial running. The key parameters related with power efficiency were studied for TWS optimization. The result was proved by experiment result, and it shows some help for accelerator engineering. (authors)

  2. Possible scenarios for the initial acceleration of electrons of the core of ball lightning

    Science.gov (United States)

    Shmatov, M. L.

    2015-12-01

    > A model for the initial acceleration of electrons of the core of ball lightning is presented, according to which this acceleration occurs on screening of the strong electric field of the positive charge injected into the atmosphere. Several scenarios for such injection, the factors favourable for the formation of ball lightning and possible experiments on such formation are considered.

  3. Simple scalings for various regimes of electron acceleration in surface plasma waves

    Energy Technology Data Exchange (ETDEWEB)

    Riconda, C.; Vialis, T. [LULI, Sorbonne Université, Université Pierre et Marie Curie, Ecole Polytechnique, CNRS UMR 7605, CEA, Paris 75005 (France); Raynaud, M. [Laboratoire des Solides Irradiés, CNRS UMR 7642, CEA-DSM-IRAMIS, Ecole Polytechnique, Université Paris-Saclay, 91128 Palaiseau (France); Grech, M. [LULI, CNRS UMR 7605, Université Pierre et Marie Curie, Ecole Polytechnique, CEA, 91128 Palaiseau (France)

    2015-07-15

    Different electron acceleration regimes in the evanescent field of a surface plasma wave are studied by considering the interaction of a test electron with the high-frequency electromagnetic field of a surface wave. The non-relativistic and relativistic limits are investigated. Simple scalings are found demonstrating the possibility to achieve an efficient conversion of the surface wave field energy into electron kinetic energy. This mechanism of electron acceleration can provide a high-frequency pulsed source of relativistic electrons with a well defined energy. In the relativistic limit, the most energetic electrons are obtained in the so-called electromagnetic regime for surface waves. In this regime, the particles are accelerated to velocities larger than the wave phase velocity, mainly in the direction parallel to the plasma-vacuum interface.

  4. Highly collimated monoenergetic target-surface electron acceleration in near-critical-density plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mao, J. Y. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern 67663 (Germany); Chen, L. M., E-mail: lmchen@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Huang, K.; Ma, Y.; Zhao, J. R.; Yan, W. C.; Ma, J. L.; Wei, Z. Y. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Li, D. Z. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Institute of High Energy Physics, CAS, Beijing 100049 (China); Aeschlimann, M. [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Kaiserslautern 67663 (Germany); Zhang, J. [Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-03-30

    Optimized-quality monoenergetic target surface electron beams at MeV level with low normalized emittance (0.03π mm mrad) and high charge (30 pC) per shot have been obtained from 3 TW laser-solid interactions at a grazing incidence. The 2-Dimension particle-in-cell simulations suggest that electrons are wake-field accelerated in a large-scale, near-critical-density preplasma. It reveals that a bubble-like structure as an accelerating cavity appears in the near-critical-density plasma region and travels along the target surface. A bunch of electrons are pinched transversely and accelerated longitudinally by the wake field in the bubble. The outstanding normalized emittance and monochromaticity of such highly collimated surface electron beams could make it an ideal beam for fast ignition or may serve as an injector in traditional accelerators.

  5. Near-surface electron acceleration during intense laser-solid interaction in the grazing incidence regime

    Science.gov (United States)

    Serebryakov, D. A.; Nerush, E. N.; Kostyukov, I. Yu.

    2017-12-01

    When a relativistically intense p-polarized laser pulse is grazingly incident onto a planar solid-state target, a slightly superluminal field structure is formed near the target surface due to the incident and reflected waves superposition. This field structure can both extract the electrons from the target and accelerate them. It is theoretically shown that the acceleration is possible and stable for a wide range of electron initial conditions. Particle-in-cell simulations confirm that this mechanism can actually take place for realistic parameters. As a result, the electron bunches with a charge of tens of nC and GeV-level energy can be produced using a laser intensity 1021-1022 W/cm2. It is also shown that the presence of a preplasma can improve acceleration, which becomes possible because of more efficient electron injection into the accelerating field structure.

  6. Proceedings of the Oak Ridge Electron Linear Accelerator (ORELA) Workshop

    International Nuclear Information System (INIS)

    Dunn, M.E.

    2006-01-01

    The Oak Ridge National Laboratory (ORNL) organized a workshop at ORNL July 14-15, 2005, to highlight the unique measurement capabilities of the Oak Ridge Electron Linear Accelerator (ORELA) facility and to emphasize the important role of ORELA for performing differential cross-section measurements in the low-energy resonance region that is important for nuclear applications such as nuclear criticality safety, nuclear reactor and fuel cycle analysis, stockpile stewardship, weapons research, medical diagnosis, and nuclear astrophysics. The ORELA workshop (hereafter referred to as the Workshop) provided the opportunity to exchange ideas and information pertaining to nuclear cross-section measurements and their importance for nuclear applications from a variety of perspectives throughout the U.S. Department of Energy (DOE). Approximately 50 people, representing DOE, universities, and seven U.S. national laboratories, attended the Workshop. The objective of the Workshop was to emphasize the technical community endorsement for ORELA in meeting nuclear data challenges in the years to come. The Workshop further emphasized the need for a better understanding of the gaps in basic differential nuclear measurements and identified the efforts needed to return ORELA to a reliable functional measurement facility. To accomplish the Workshop objective, nuclear data experts from national laboratories and universities were invited to provide talks emphasizing the unique and vital role of the ORELA facility for addressing nuclear data needs. ORELA is operated on a full cost-recovery basis with no single sponsor providing complete base funding for the facility. Consequently, different programmatic sponsors benefit by receiving accurate cross-section data measurements at a reduced cost to their respective programs; however, leveraging support for a complex facility such as ORELA has a distinct disadvantage in that the programmatic funds are only used to support program

  7. Proceedings of the Oak Ridge Electron Linear Accelerator (ORELA) Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, M.E.

    2006-02-27

    The Oak Ridge National Laboratory (ORNL) organized a workshop at ORNL July 14-15, 2005, to highlight the unique measurement capabilities of the Oak Ridge Electron Linear Accelerator (ORELA) facility and to emphasize the important role of ORELA for performing differential cross-section measurements in the low-energy resonance region that is important for nuclear applications such as nuclear criticality safety, nuclear reactor and fuel cycle analysis, stockpile stewardship, weapons research, medical diagnosis, and nuclear astrophysics. The ORELA workshop (hereafter referred to as the Workshop) provided the opportunity to exchange ideas and information pertaining to nuclear cross-section measurements and their importance for nuclear applications from a variety of perspectives throughout the U.S. Department of Energy (DOE). Approximately 50 people, representing DOE, universities, and seven U.S. national laboratories, attended the Workshop. The objective of the Workshop was to emphasize the technical community endorsement for ORELA in meeting nuclear data challenges in the years to come. The Workshop further emphasized the need for a better understanding of the gaps in basic differential nuclear measurements and identified the efforts needed to return ORELA to a reliable functional measurement facility. To accomplish the Workshop objective, nuclear data experts from national laboratories and universities were invited to provide talks emphasizing the unique and vital role of the ORELA facility for addressing nuclear data needs. ORELA is operated on a full cost-recovery basis with no single sponsor providing complete base funding for the facility. Consequently, different programmatic sponsors benefit by receiving accurate cross-section data measurements at a reduced cost to their respective programs; however, leveraging support for a complex facility such as ORELA has a distinct disadvantage in that the programmatic funds are only used to support program

  8. Separation of Accelerated Electrons and Positrons in the Relativistic Reconnection

    Czech Academy of Sciences Publication Activity Database

    Karlický, Marian

    2008-01-01

    Roč. 674, č. 2 (2008), s. 1211-1216 ISSN 0004-637X R&D Projects: GA MŠk(CZ) LC06014; GA AV ČR IAA300030701 Institutional research plan: CEZ:AV0Z10030501 Keywords : acceleration of particles * plasmas * relativity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 6.331, year: 2008

  9. Transient phenomena during electron beam injection in the Saclay 45 MeV accelerator

    International Nuclear Information System (INIS)

    Marcou, J.; Papiernik, A.; Wartski, L.; Bolore, M.; Filippi, G.; Roland, S.

    1969-01-01

    The principal features of transient phenomena, when electron beams are injected in a constant field linear accelerator, are analysed and interpreted by the use of a simple theory. Influence of these transient phenomena on the energy of accelerated particles is observed using a relatively precise method. For very large beam currents, non linear phenomena due to beam deformation can be exhibited, when the electron velocity is not exactly equal to the light velocity. (author) [fr

  10. Research on cw electron accelerators using room-temperature rf structures: Annual report

    International Nuclear Information System (INIS)

    1986-01-01

    This joint NBS-Los Alamos project of ''Research on CW Electron Accelerators Using Room-Temperature RF Structures'' began seven years ago with the goal of developing a technology base for cw electron accelerators. In this report we describe our progress during FY 1986 and present our plans for completion of the project. First, however, it is appropriate to review the past contributions of the project, describe its status, and indicate its future benefits

  11. ULF wave penetration in the inner magnetosphere related to radiation belt electron acceleration and losses: Observations and model simulations

    Science.gov (United States)

    Georgiou, Marina; Daglis, Ioannis; Zesta, Eftyhia; Sibeck, David; Fok, Mei-ching; Balasis, Georgios; Mann, Ian; Tsinganos, Kanaris

    2017-04-01

    Periodic oscillations in the Earth's magnetic field with frequencies in the range of a few mHz (ULF waves) can influence radiation belt dynamics due to their potential for strong interactions with charged particles and in particular, relativistic electrons. We have explored possible relationships between the spatial and temporal profile of ULF wave power with relativistic electron fluxes as well as different solar wind parameters. We used data from multiple ground magnetometer arrays contributing to the worldwide SuperMAG collaboration to calculate the ULF wave power in the Pc5 frequency band (2 - 7 mHz) from for a total of 40 moderate and intense magnetic storms over the last solar cycle 23. During the main phase of both sets of storms, there is a marked penetration of Pc5 wave power to L-shells as low as 2-3. The penetration of ULF waves is deeper into the inner magnetosphere during intense magnetic storms characterised by enhanced post-storm electron fluxes. Furthermore, later in the recovery phase, enhanced Pc5 wave activity was found to persist longer for storms marked by electron-enhanced storms flux enhancement than for those that do not produce such electron flux enhancements. Growth and decay characteristics of Pc5 waves were explored in association with the plasmapause location, determined from IMAGE EUV observations. Pc5 wave power enhancements and relativistic electron acceleration were not only intimately linked, but also restricted beyond the plasmapause. These observations provided the basis for a superposed epoch analysis, the results of which are compared to predictions from the Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model. These simulations are critical for understanding the extent to which ULF wave electric fields are responsible for the observed electron acceleration and for examining the nature of mechanisms responsible for driving such large-amplitude ULF waves in the magnetosphere. This work has been supported by the NOA

  12. Low Secondary Electron Yield Carbon Coatings for Electron-cloud Mitigation in Modern Particle Accelerators

    CERN Document Server

    Yin Vallgren, Christina; Calatroni, Sergio; Chiggiato, Paolo; Costa Pinto, Pedro; Marques, Hugo; Neupert, Holger; Taborelli, Mauro; Vollenberg, Wilhelmus; Wevers, Ivo; Yaqub, Kashif

    2010-01-01

    Electron-cloud is one of the main limitations for particle accelerators with positively charged beams of high intensity and short bunch spacing, as the SPS at CERN. The Secondary Electron Yield (SEY) of the inner surface of the vacuum chamber is the main parameter governing the phenomenon. The effect could be eliminated by coating the vacuum chambers with a material of low SEY, which does not require bake-out and is robust against air exposure. For such a purpose amorphous carbon (a-C) coatings were produced by magnetron sputtering of graphite targets. They exhibit maximum SEY between 0.95 and 1.05 after air transfer to the measuring instrument. After 1 month of air exposure the SEY rises by 10 - 20 % of the initial values. Storage in desiccator or by packaging in Al foil makes this increase negligible. The coatings have a similar X-ray photoelectron spectroscopy (XPS) C1s spectrum for a large set of deposition parameters and exhibit an enlarged linewidth compared to HOPG graphite. The static outgassing witho...

  13. 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

  14. Towards a 12 GeV electron accelerator for nuclear physics with a 100% duty cycle

    International Nuclear Information System (INIS)

    Aune, B.; Belmont, J.L.; Didelez, J.P.; Leleux, G.; Loiseaux, J.M.; Gouttefangeas, M.; Prome, M.; Tkatchenko, A.

    1991-01-01

    For the future researches in nuclear physics it is widely believed that the electromagnetic probe is a very useful tool. Therefore in 1989 a preliminary study of a 4 GeV, 100% duty cycle accelerator was carried out. The accelerator consists essentially of a recirculating linac using the superconducting cavities being developed at Saclay. Two nuclear physics experimental rooms would be fed simultaneously at the 1.5 GHz RF frequency. Provisions could be made for a later upgrading of the accelerator up to 12 GeV, as recommended by the French Academy of Sciences, although other approaches towards a 12 GeV electron accelerator are also under study

  15. Application of PIN photodiodes on the detection of X-rays generated in an electron accelerator

    International Nuclear Information System (INIS)

    Mondragon-Contreras, L.; Ramirez-Jimenez, F.J.; Garcia-Hernandez, J.M.; Torres-Bribiesca, M.A.; Lopez-Callejas, R.; Aguilera-Reyes, E.F.; Pena-Eguiluz, R.; Lopez-Valdivia, H.; Carrasco-Abrego, H.

    2009-01-01

    PIN photodiodes are used in a novel application for the determination, within the energy range from 90 to 485 keV, of the intensity of X-rays generated by an experimental electron accelerator. An easily assembled X-ray monitor has been built with a low-cost PIN photodiode and operational amplifiers. The output voltage signal obtained from this device can be related to the electron beam current and the accelerating voltage of the accelerator in order to estimate the dose rate delivered by bremsstrahlung.

  16. Modeling of electron cyclotron resonance acceleration in a stationary inhomogeneous magnetic field

    Directory of Open Access Journals (Sweden)

    Valeri D. Dougar-Jabon

    2008-04-01

    Full Text Available In this paper, the cyclotron autoresonance acceleration of electrons in a stationary inhomogeneous magnetic field is studied. The trajectory and energy of electrons are found through a numerical solution of the relativistic Newton-Lorentz equation by a finite difference method. The electrons move along a TE_{112} cylinder cavity in a steady-state magnetic field whose axis coincides with the cavity axis. The magnetic field profile is such that it keeps the phase difference between the electric microwave field and the electron velocity vector within the acceleration phase band. The microwaves amplitude of 6  kV/cm is used for numerical calculations. It is shown that an electron with an initial longitudinal energy of 8 keV can be accelerated up to 260 keV by 2.45 GHz microwaves at a distance of 17 cm.

  17. Thermionic gun control system for the CEBAF [Continuous Electron Beam Accelerator Facility] injector

    International Nuclear Information System (INIS)

    Pico, R.; Diamond, B.; Fugitt, J.; Bork, R.

    1989-01-01

    The injector for the CEBAF accelerator must produce a high-quality electron beam to meet the overall accelerator specifications. A Hermosa electron gun with a 2 mm-diameter cathode and a control aperture has been chosen as the electron source. This must be controlled over a wide range of operating conditions to meet the beam specifications and to provide flexibility for accelerator commissioning. The gun is controlled using Computer Automated Measurement and Control (CAMAC IEEE-583) technology. The system employs the CAMAC-based control architecture developed at CEBAF. The control system has been tested, and early operating data on the electron gun and the injector beam transport system has been obtained. This system also allows gun parameters to be stored at the operator location, without paralyzing operation. This paper describes the use of this computer system in the control of the CEBAF electron gun. 2 refs., 6 figs., 1 tab

  18. High-gradient two-beam electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L. [Omega-P, Inc., New Haven, CT (United States)

    2014-11-04

    The main goal for this project was to design, build, and evaluate a detuned-cavity, collinear, two-beam accelerator structure. Testing was to be at the Yale University Beam Physics Laboratory, under terms of a sub-grant from Omega-P to Yale. Facilities available at Yale for this project include a 6-MeV S-band RF gun and associated beam line for forming and transporting a ~1 A drive beam , a 300 kV beam source for use as a test beam, and a full panoply of laboratory infrastructure and test equipment. During the first year of this project, availability and functionality of the 6-MeV drive beam and 300 kV test beam were confirmed, and the beam line was restored to a layout to be used with the two-beam accelerator project. Major efforts during the first year were also focused on computational design and simulation of the accelerator structure itself, on beam dynamics, and on beam transport. Effort during the second year was focussed on building and preparing to test the structure, including extensive cold testing. Detailed results from work under this project have been published in twelve archival journal articles, listed in Section IV of the technical report.

  19. Physical design of 9 MeV travelling wave electron linac accelerating tube

    International Nuclear Information System (INIS)

    Chen Huaibi; Ding Xiaodong; Lin Yuzheng

    2000-01-01

    An accelerating tube is described. It is a part of an accelerator used for inspection of vehicle cargoes in rail cars, trucks, shipping containers, or airplanes in customs. A klystron with power of 4 MW and frequency of 2856 MHz will be applied to supply microwave power. The electrons can be accelerated by a travelling wave in the accelerating tube about 220 cm long, with a buncher whose capture efficiency is more than 80%. Energy of electrons after travelling through the tube can reach 9 MeV (pulse current intensity 170 mA) or 6 MeV (pulse current intensity 300 mA). Physical design of the accelerating tube, including the calculations of longitudinal particle dynamics, structure parameter and working character is carried out

  20. Beam dynamics analysis of femtosecond microbunches produced by the staged electron laser acceleration experiment

    Directory of Open Access Journals (Sweden)

    F. Zhou

    2003-05-01

    Full Text Available Preservation of the femtosecond (fs microbunches, created during laser acceleration, is a crucial step to enable staging of the laser acceleration process. This paper focuses on the optimization of the beam dynamics of fs microbunches transported through the staged electron laser acceleration (STELLA-II experiment being carried out at the Brookhaven National Laboratory Accelerator Test Facility. STELLA-II consists of an inverse free electron laser (IFEL untapered undulator, which acts as an electron beam energy modulator; a magnetic chicane, which acts as a buncher; a second IFEL tapered undulator, which acts as an accelerator; and a dipole, which serves as an energy spectrometer. When the energy-modulated macrobunch traverses through the chicane and a short drift space, microbunches of order fs in duration (i.e., ∼3  fs FWHM are formed. The 3-fs microbunches are accelerated by interacting with a high-power CO_{2} laser beam in the following tapered undulator. These extremely short microbunches may experience significant space charge and coherent synchrotron radiation effects when traversing the STELLA-II transport line. These effects are analyzed and the safe operating conditions are determined. With less than 0.5-pC microbunch charge, both microbunch debunching and emittance growth are negligible, and the energy-spread increase is less than 5%. These results are also useful for the laser electron acceleration project at SLAC and in possible future programs where the fs microbunches are employed for other purposes.

  1. Analysis of the power system from an electron beam accelerator and the correlation with the theoretical dosimetry for radiation processing

    International Nuclear Information System (INIS)

    Somessari, Samir Luiz; Somessari, Elizabeth S. Ribeiro; Silveira, Carlos Gaia da; Calvo, Wilson Aparecido Parejo

    2013-01-01

    Dynamitron DC1500/25/04 type electron beam accelerator (EBA), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN/CNEN-SP in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: for sterilization of medical, pharmaceutical and biological products; treatment of industrial and domestic effluents and sludge; preservation and disinfestation of foods and agricultural products; lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; treatment of effluent from petroleum production units; crosslinking of foams, wires and electric cables; composite and nanocomposite materials and carbon fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; natural polymers and multilayer packages irradiation, and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the point of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04 accelerator, such as, voltage and root-mean-square (RMS) current in the oscillator system, high voltage generator and waveform, using software developed in the

  2. Analysis of the power system from an electron beam accelerator and the correlation with the theoretical dosimetry for radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir Luiz; Somessari, Elizabeth S. Ribeiro; Silveira, Carlos Gaia da; Calvo, Wilson Aparecido Parejo, E-mail: somessar@ipen.br, E-mail: esomessa@ipen.br, E-mail: cgsilvei@ipen.br, E-mail: wapcalvo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Dynamitron DC1500/25/04 type electron beam accelerator (EBA), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN/CNEN-SP in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: for sterilization of medical, pharmaceutical and biological products; treatment of industrial and domestic effluents and sludge; preservation and disinfestation of foods and agricultural products; lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; treatment of effluent from petroleum production units; crosslinking of foams, wires and electric cables; composite and nanocomposite materials and carbon fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; natural polymers and multilayer packages irradiation, and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the point of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04 accelerator, such as, voltage and root-mean-square (RMS) current in the oscillator system, high voltage generator and waveform, using software developed in the

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

    Science.gov (United States)

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

    2016-03-01

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

  4. 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)

  5. Development of an automated system for the operation of an electron beam accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir L.; Moura, João A.; Calvo, Wilson Ap. Parejo, E-mail: somessar@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    Electron beam accelerators are used in many applications, such as basic physical research, chemistry, medicine, molecular biology, microelectronics, agriculture and industry, among others. The majority of the accelerators have electrons from a hot tungsten filament and their energy is increased as it passes through an electric field in the vacuum chamber. For industrial purposes, the most common model is Dynamitrons®. At IPEN-CNEN/SP, there is an electron beam accelerator Dynamitron® Type (Manufactured by RDI- Radiation Dynamics Inc., 1978) model DC1500/25/4. The technology applied was available in the 60's and 70's, but, nowadays is obsolete. Moreover, there are not original spare parts for this equipment any longer. The aim of this work is to develop a nationalized automated operation system for the accelerator, to replace the old equipment. (author)

  6. Ion response to relativistic electron bunches in the blowout regime of laser-plasma accelerators.

    Science.gov (United States)

    Popov, K I; Rozmus, W; Bychenkov, V Yu; Naseri, N; Capjack, C E; Brantov, A V

    2010-11-05

    The ion response to relativistic electron bunches in the so called bubble or blowout regime of a laser-plasma accelerator is discussed. In response to the strong fields of the accelerated electrons the ions form a central filament along the laser axis that can be compressed to densities 2 orders of magnitude higher than the initial particle density. A theory of the filament formation and a model of ion self-compression are proposed. It is also shown that in the case of a sharp rear plasma-vacuum interface the ions can be accelerated by a combination of three basic mechanisms. The long time ion evolution that results from the strong electrostatic fields of an electron bunch provides a unique diagnostic of laser-plasma accelerators.

  7. Development of an automated system for the operation of an electron beam accelerator

    International Nuclear Information System (INIS)

    Somessari, Samir L.; Moura, João A.; Calvo, Wilson Ap. Parejo

    2017-01-01

    Electron beam accelerators are used in many applications, such as basic physical research, chemistry, medicine, molecular biology, microelectronics, agriculture and industry, among others. The majority of the accelerators have electrons from a hot tungsten filament and their energy is increased as it passes through an electric field in the vacuum chamber. For industrial purposes, the most common model is Dynamitrons®. At IPEN-CNEN/SP, there is an electron beam accelerator Dynamitron® Type (Manufactured by RDI- Radiation Dynamics Inc., 1978) model DC1500/25/4. The technology applied was available in the 60's and 70's, but, nowadays is obsolete. Moreover, there are not original spare parts for this equipment any longer. The aim of this work is to develop a nationalized automated operation system for the accelerator, to replace the old equipment. (author)

  8. Quasi-monoenergetic laser-plasma acceleration of electrons to 2 GeV

    Science.gov (United States)

    Wang, Xiaoming; Zgadzaj, Rafal; Fazel, Neil; Li, Zhengyan; Yi, S. A.; Zhang, Xi; Henderson, Watson; Chang, Y.-Y.; Korzekwa, R.; Tsai, H.-E.; Pai, C.-H.; Quevedo, H.; Dyer, G.; Gaul, E.; Martinez, M.; Bernstein, A. C.; Borger, T.; Spinks, M.; Donovan, M.; Khudik, V.; Shvets, G.; Ditmire, T.; Downer, M. C.

    2013-06-01

    Laser-plasma accelerators of only a centimetre’s length have produced nearly monoenergetic electron bunches with energy as high as 1 GeV. Scaling these compact accelerators to multi-gigaelectronvolt energy would open the prospect of building X-ray free-electron lasers and linear colliders hundreds of times smaller than conventional facilities, but the 1 GeV barrier has so far proven insurmountable. Here, by applying new petawatt laser technology, we produce electron bunches with a spectrum prominently peaked at 2 GeV with only a few per cent energy spread and unprecedented sub-milliradian divergence. Petawatt pulses inject ambient plasma electrons into the laser-driven accelerator at much lower density than was previously possible, thereby overcoming the principal physical barriers to multi-gigaelectronvolt acceleration: dephasing between laser-driven wake and accelerating electrons and laser pulse erosion. Simulations indicate that with improvements in the laser-pulse focus quality, acceleration to nearly 10 GeV should be possible with the available pulse energy.

  9. Electron-Transfer Acceleration Investigated by Time Resolved Infrared Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Vlček, Antonín; Kvapilová, Hana; Towrie, M.; Záliš, Stanislav

    2015-01-01

    Roč. 48, č. 3 (2015), s. 868-876 ISSN 0001-4842 Institutional support: RVO:61388955 Keywords : electron transfer * infrared spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 22.003, year: 2015

  10. Accelerated Aging Platform for Prognostics of Power Electronics

    Data.gov (United States)

    National Aeronautics and Space Administration — To advance the field of electronics prognostics, the study of transistor fault modes and their precursors is essential. This paper reports on a platform for the...

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

    Science.gov (United States)

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

    2015-03-06

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

  12. Optimizing chirped laser pulse parameters for electron acceleration in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Akhyani, Mina; Jahangiri, Fazel; Niknam, Ali Reza; Massudi, Reza, E-mail: r-massudi@sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran 1983969411 (Iran, Islamic Republic of)

    2015-11-14

    Electron dynamics in the field of a chirped linearly polarized laser pulse is investigated. Variations of electron energy gain versus chirp parameter, time duration, and initial phase of laser pulse are studied. Based on maximizing laser pulse asymmetry, a numerical optimization procedure is presented, which leads to the elimination of rapid fluctuations of gain versus the chirp parameter. Instead, a smooth variation is observed that considerably reduces the accuracy required for experimentally adjusting the chirp parameter.

  13. Design of electron beam accelerator for microwave application

    Science.gov (United States)

    Prestwich, K. R.

    Relativistic electron beams are used for generating high power microwaves. These microwave sources require electron beam generators spanning significant ranges in voltage and impedance. The pulsed power technology used to generate these electron beams is presented. Electron beam generators that produce beams with pulse durations in the 10 ns to 100 ns regime consist of an energy storage section, pulse shaping section, and an electron beam diode. The energy storage section is either a Marx generator or capacitor bank-pulsed transformer. The pulse shaping is done with high-voltage transmission lines. The electron beam diode is usually a cold-cathode, space-charge-limited flow device. For longer pulses (approx 1 microsec) the energy storage and pulse shaping can be combined. Lumped-element pulsed-forming networks (PFN) can be designed to produce the desired pulse shape. The Marx generator becomes one of the elements of the PFN. Alternatively, a low voltage PFN followed by a highly coupled transformer can be used. Basic design principles for all of the above subsystems are discussed. Both PFLs and PFNs can also be operated as inductive storage systems with opening switches.

  14. Spatial Control of Laser Wakefield Accelerated Electron Beams

    Science.gov (United States)

    Maksimchuk, A.; Behm, K.; Zhao, T.; Joglekar, A. S.; Hussein, A.; Nees, J.; Thomas, A. G. R.; Krushelnick, K.; Elle, J.; Lucero, A.; Samarin, G. M.; Sarry, G.; Warwick, J.

    2017-10-01

    The laser wakefield experiments to study and control spatial properties of electron beams were performed using HERCULES laser at the University of Michigan at power of 100 TW. In the first experiment multi-electron beam generation was demonstrated using co-propagating, parallel laser beams with a π-phase shift mirror and showing that interaction between the wakefields can cause injection to occur for plasma and laser parameters in which a single wakefield displays no significant injection. In the second experiment a magnetic triplet quadrupole system was used to refocus and stabilize electron beams at the distance of 60 cm from the interaction region. This produced a 10-fold increase in remote gamma-ray activation of 63Cu using a lead converter. In the third experiment measurements of un-trapped electrons with high transverse momentum produce a 500 mrad (FWHM) ring. This ring is formed by electrons that receive a forward momentum boost by traversing behind the bubble and its size is inversely proportional to the plasma density. The characterization of divergence and charge of this electron ring may reveal information about the wakefield structure and trapping potential. Supported by U.S. Department of Energy and the National Nuclear Security Administration and Air Force Office of Scientific Research.

  15. Shock-drift accelerated electrons and n-distribution

    Czech Academy of Sciences Publication Activity Database

    Vandas, Marek; Karlický, Marian

    2016-01-01

    Roč. 591, July (2016), A127/1-A127/6 ISSN 0004-6361 R&D Projects: GA ČR(CZ) GA14-19376S; GA ČR GA15-17490S; GA ČR GAP209/12/0103 Grant - others:EC(XE) 295272; EC(XE) 606862 Program:FP7; FP7 Institutional support: RVO:67985815 Keywords : shock waves * acceleration of particles * Sun flares Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

  16. Electron beam accelerator at BARC-BRIT complex - electron beam processing of materials and industrial utilization

    International Nuclear Information System (INIS)

    Khader, S.A.; Patkari, R.K.; Sharma, K.S.S.

    2013-01-01

    During the last decade, the 2MeV/20kW electron beam (EB) accelerator located at BARC-BRIT complex, Vashi has been successfully utilised for non-thermal applications to develop speciality products useful for the industry. Polymer materials are exposed to high energy electrons to induce crosslinking and degradation reactions in a number of industrial products without the use of external chemicals and additives. Various EB crosslinked products viz. PE O-rings, automotive components, automobile tyres, electrical insulations, etc have been found to be much superior in quality compared to those produced conventionally. A process has been developed to enhance colours in the polished diamonds and gem stones using EB irradiation at the facility which has attracted much attention in the Indian diamond industry as a value-addition process. Recycling of polymer waste processed under EB to produce microfine PTFE powder, to reuse in automobile industry etc. has shown good potential for the industrial use. The process feasibility both in terms of economics and technology have been amply demonstrated on a technological scale by installing special conveyors at our facility for irradiating various industrial products. Around 100 km cable insulations, 1.5 million PE O-rings and more than 40000 carats of polished diamonds have been processed in our facility over a period of time on commercial scale. Encouraged with the results, Indian private entrepreneurs have set up dedicated EB machines in some of the most significant industries producing wire and cables, electrical gadgets based on polymer composites, automobile tyres and diamonds. The products are unique in properties and are in some cases, became import substitutes. The industry is now fully geared up to adapt the technology by realising the advantages viz ease in adaptability, convenient, safe and environmental-friendly nature. Encouraged by the process demonstrations, while five EB accelerators were setup and are in operation

  17. 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)

  18. Ionospheric electron acceleration by electromagnetic waves near regions of plasma resonances

    International Nuclear Information System (INIS)

    Villalon, E.

    1989-01-01

    Electron acceleration by electromagnetic fields propagating in the inhomogeneous ionospheric plasma is investigated. It is found that high-amplitude short wavelength electrostatic waves are generated by the incident electromagnetic fields that penetrate the radio window. These waves can very efficiently transfer their energy to the electrons if the incident frequency is near the second harmonic of the cyclotron frequency

  19. Electron acceleration in supernova remnants and diffuse gamma rays above 1 GeV

    DEFF Research Database (Denmark)

    Pohl, M.; Esposito, J.A.

    1998-01-01

    The recently observed X-ray synchrotron emission from four supernova remnants (SNRs) has strengthened the evidence that cosmic-ray electrons are accelerated in SNRs. We show that if this is indeed the case, the local electron spectrum will be strongly time-dependent, at least above roughly 30 Ge...

  20. Correlated observations of intensified whistler waves and electron acceleration around the geostationary orbit

    International Nuclear Information System (INIS)

    Xiao Fuliang; He Zhaoguo; Tang Lijun; Zong Qiugang; Wang Chengrui; Su Zhenpeng

    2012-01-01

    We report correlated observations of enhanced whistler waves and energetic electron acceleration collected by multiple satellites specifically near the geostationary orbit during the 7–10 November 2004 superstorms, together with multi-site observations of ULF wave power measured on the ground. Energetic (>0.6 MeV) electron fluxes are found to increase significantly during the recovery phase, reaching a peak value by ∼100 higher than the prestorm level. In particular, such high electron flux corresponds to intensified whistler wave activities but to the weak ULF wave power. This result suggests that wave–particle interaction appears to be more important than inward radial diffusion in acceleration of outer radiation belt energetic electrons in this event, assisting to better understand the acceleration mechanism. (paper)

  1. Radiosensitivity of chlorella after medium energy accelerated electron irradiation

    International Nuclear Information System (INIS)

    Roux, J.C.

    1966-06-01

    The survival curves (capability of multiplication) of chlorella pyrenoidosa after irradiations can be used for soft electrons (0.65 and 1 MeV), hence penetrating into only 2 to 4 millimeters of water: the algae are laying on porous membranes and the doses are calculated from the power of the electron beam measured by the electric current on a metallic target or by Fricke's dosimetry. With these techniques, it is showed and discussed the part of anoxia in the radioprotection (magnitude or reduction of the dose calculated from the slope of survival curves: 2.5 ) that is more important than the restoration studied by the fractionation of the dose. The 0.65 and 1 MeV electrons have a biologic effect lesser than 180 keV X-rays (RBE - relative biological efficiency - calculated on the slope of survival curves is 0.92 in aerated irradiation, 0.56 in the deoxygenated irradiation). (author) [fr

  2. Magnetic Field Generation and Electron Acceleration in Relativistic Laser Channel

    International Nuclear Information System (INIS)

    Kostyukov, I.Yu.; Shvets, G.; Fisch, N.J.; Rax, J.M.

    2001-01-01

    The interaction between energetic electrons and a circularly polarized laser pulse inside an ion channel is studied. Laser radiation can be resonantly absorbed by electrons executing betatron oscillations in the ion channel and absorbing angular momentum from the laser. The absorbed angular momentum manifests itself as a strong axial magnetic field (inverse Faraday effect). The magnitude of this magnetic field is calculated and related to the amount of the absorbed energy. Absorbed energy and generated magnetic field are estimated for the small and large energy gain regimes. Qualitative comparisons with recent experiments are also made

  3. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Science.gov (United States)

    He, Z.-H.; Thomas, A. G. R.; Beaurepaire, B.; Nees, J. A.; Hou, B.; Malka, V.; Krushelnick, K.; Faure, J.

    2013-02-01

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  4. 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.

  5. Parity violation workshop: CEBAF [Continuous Electron Beam Accelerator Facility

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1986-01-01

    This paper discusses the use of electron scattering experiments for exploring parity violation in the nuclear domain. It is shown how such experiments can test the structure of strong interactions, the local gauge theory quantum chromodynamics based on color, and the unified gauge theory of electroweak interactions. 14 refs., 13 figs., 1 tab

  6. Hadron physics at the new CW electron accelerators

    International Nuclear Information System (INIS)

    Burkert, V.D.

    1990-01-01

    Major trends of the physics program related to the study of hadron structure and hadron spectroscopy at the new high current, high duty cycle electron machines are discussed. It is concluded that planned experiments at these machines may have important impact on our understanding of the strong interaction by studying the internal structure and spectroscopy of the nucleon and lower mass hyperon states

  7. An Economic Analysis of Electron Accelerators and Cobalt-60 for Irradiating Food

    OpenAIRE

    Morrison, Rosanna Mentzer

    1989-01-01

    Average costs per pound of irradiating food are similar for the electron accelerator and cobalt-60 irradiators analyzed in this study, but initial investment costs can vary by $1 million. Irradiation costs range from 0.5 to 7 cents per pound and decrease as annual volumes treated increase. Cobalt-60 is less expensive than electron beams for annual volumes below 50 million pounds. For radiation source requirements above the equivalent of 1 million curies of cobalt-60, electron beams are more e...

  8. Comparing Solar-Flare Acceleration of >-20 MeV Protons and Electrons Above Various Energies

    Science.gov (United States)

    Shih, Albert Y.

    2010-01-01

    A large fraction (up to tens of percent) of the energy released in solar flares goes into accelerated ions and electrons, and studies indicate that these two populations have comparable energy content. RHESSI observations have shown a striking close linear correlation between the 2.223 MeV neutron-capture gamma-ray line and electron bremsstrahlung emission >300 keV, indicating that the flare acceleration of >^20 MeV protons and >300 keV electrons is roughly proportional over >3 orders of magnitude in fluence. We show that the correlations of neutron-capture line fluence with GOES class or with bremsstrahlung emission at lower energies show deviations from proportionality, primarily for flares with lower fluences. From analyzing thirteen flares, we demonstrate that there appear to be two classes of flares with high-energy acceleration: flares that exhibit only proportional acceleration of ions and electrons down to 50 keV and flares that have an additional soft, low-energy bremsstrahlung component, suggesting two separate populations of accelerated electrons. We use RHESSI spectroscopy and imaging to investigate a number of these flares in detail.

  9. Non-channel magnetron gun as the electron source for resonance linear accelerator

    International Nuclear Information System (INIS)

    Ivanov, G.M.; Makhnenko, L.A.; Cherenshchikov, S.A.

    1999-01-01

    Studies on the magnetron gun with a cold cathode being part of linear accelerator on the travelling wave are described. Two modes of the gun operation differing by presence of UHF field of the pre-buncher near the gun are observed. In the mode without UHF field the short (about 2 ns) pulses of accelerated electrons with amplitude up to 0.5 A at the gun current up to 20 A were obtained. The presence of UHF field near the gun makes it possible to obtain the beam of higher duration (up to 1.0 μs), but with current up to 20 mA at the accelerator outlet and up to 1 A at the gun outlet. The mechanism of the gun operation is concerned with the secondary-electron current increase and setting self-sustaining secondary emission. Gun characteristics under study are acceptable for the purposes of injection into accelerator [ru

  10. 50 MeV Run of the IOTA / FAST Electron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Edstrom Jr., D.; et al.

    2017-02-02

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

  11. Radiation vulcanization of natural rubber latex (NRL) using low energy electron beam accelerator

    International Nuclear Information System (INIS)

    Feroza Akhtar; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The electron beam induced vulcanization of natural rubber latex has been studied using low energy Electron Beam (EB) accelerators of 300, 250 and 175 keV ne latex was irradiated in a special type stainless steel reaction reactor with a stirrer at the bottom of the reactor. From the results it was found that 300 and 250 keV accelerators could effectively vulcanize NRL. But accelerator of 175 keV is too low energy to vulcanize the latex. At the same time a drum type irradiator where thin layer of NRL was irradiated by accelerator, was used for vulcanization of NRL. This type of irradiator also showed good physical properties of vulcanized latex. The effects of beam current and stirrer speed on vulcanization were studied

  12. The CEBAF [Continuous Electron Beam Accelerator Facility] superconducting accelerator: An overview

    International Nuclear Information System (INIS)

    Leemann, C.W.

    1986-01-01

    The CEBAF accelerator is a CW linac based on rf superconductivity and making use of multiple recirculation. Its major components are a 50 MeV injector, two linac segments of 0.5 GeV energy gain each, and recirculator arcs connecting the two linac segments. Each linac segment consists of 25 cryomodules, separated by warm sections with quadrupoles, steering magnets, and beam diagnostics. Each cryomodule contains 8, 1500 MHz, 5-cell, Cornell type cavities with waveguide couplers for fundamental power and HOM damping, each cavity being powered by its own klystron. Recirculator arcs are vertically stacked, large radius, strong focusing beam lines that minimize synchrotron radiation effects. A high quality (ΔE/E ∼ 10 -4 , ε ∼ 10 -9 m) beam of 200μA, 100% duty factor, with 0.5 GeV ≤ E ≤ 4.0 GeV will be generated

  13. Shock drift electron acceleration and generation of waves

    Czech Academy of Sciences Publication Activity Database

    Karlický, Marian; Vandas, Marek

    2007-01-01

    Roč. 55, č. 15 (2007), s. 2336-2339 ISSN 0032-0633 R&D Projects: GA AV ČR 1QS300120506; GA AV ČR IAA300030701; GA ČR GA205/04/0358; GA ČR GA205/06/0875 Institutional research plan: CEZ:AV0Z10030501 Keywords : electrons beam * electromagnetic waves * solar radio bursts Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.842, year: 2007

  14. 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

  15. Calculation of a concrete shielding for an ILU-8 D electron accelerator

    International Nuclear Information System (INIS)

    Helal, A.; Imam, A.

    1996-01-01

    A concrete shielding for an electron accelerator of 1 MeV is suggested to replace its structural steel shielding. The thickness of such a shield is calculated. The calculational model used is based on standard and transmission curves given in the literature. The calculated concrete shielding is generally adequate to attenuate the accelerator produced radiation to a level 1 μ Gy/h or less at any point outside of the vault enclosure. 5 figs

  16. Uses of low-energy electrons accelerators in paints and varnishes: general aspects

    International Nuclear Information System (INIS)

    Yamasaki, M.C.R.

    1992-01-01

    The author presents a brief overview of the applications of low-energy beam accelerators in surface coating curing of paints and varnishes. The process, based on radiation-induced polymerization is described with particular reference to the more salient problems involved: the use of ultraviolet or electron beam as source of radiation; types of industrial accelerators; irradiation dose; dose rates and the best materials to be cured. Several practical radiation curing uses are also reported. (B.C.A.)

  17. The drive system of 100 MeV electron linear accelerator

    International Nuclear Information System (INIS)

    Sun Yuzhen; Su Guoping; Wang Xiulong; Yang Tianlu

    1990-01-01

    The principle, structure, measured result and technical performance of microwave drive system for 100 MeV electron linear accelerator are presented. In this system the peak power of 15 kW is produced by the middle power klystron. The power is divided into 6 parts, as it passes through the microwave output device 6 high power klystron are drived. The results show this system has simple structure and good characteristic. This system completely satisfies accelerator requiement

  18. Characteristics, Perceived Side Effects and Benefits of Electronic Cigarette Use: A Worldwide Survey of More than 19,000 Consumers

    Directory of Open Access Journals (Sweden)

    Konstantinos E. Farsalinos

    2014-04-01

    Full Text Available Background: Electronic cigarette (EC use has grown exponentially over the past few years. The purpose of this survey was to assess the characteristics and experiences of a large sample of EC users and examine the differences between those who partially and completely substituted smoking with EC use. Methods: A questionnaire was prepared, translated into 10 different languages and uploaded in an online survey tool. EC users were asked to participate irrespective of their current smoking status. Participants were divided according to their smoking status at the time of participation in two subgroups: former smokers and current smokers. Results: In total, 19,414 participants were included in the analysis, with 88 of them (0.5% reported not being smokers at the time of EC use initiation. Complete substitution of smoking was reported by 81.0% of participants (former smokers while current smokers had reduced smoking consumption from 20 to 4 cigarettes per day. They were using ECs for a median of 10 months. They initiated EC use with a median of 18 mg/mL nicotine-concentration liquids; 21.5% used higher than 20 mg/mL. Only 3.5% of participants were using 0-nicotine liquids at the time of the survey. Former smokers were highly dependent (Fagerström Test for Cigarette Dependence = 7 and were heavier smokers (21 cigarettes per day when smoking compared to current smokers. The most important reasons for initiating EC use for both subgroups was to reduce the harm associated with smoking and to reduce exposure of family members to second-hand smoking. Most considered ECs as less harmful than tobacco cigarettes, while 11.0% considered them absolutely harmless. Side effects were reported by more than half of the participants (59.8%, with the most common being sore/dry mouth and throat; side effects were mild and in most cases were subsequently resolved (partially or completely. Participants experienced significant benefits in physical status and improvements

  19. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe.

    Science.gov (United States)

    Chen, Y H; Yang, X Y; Lin, C; Wang, L; Xu, M; Wang, X G; Xiao, C J

    2014-11-01

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  20. Radiolytic decomposition of environmental contaminants using an electron accelerator

    International Nuclear Information System (INIS)

    Matthews, S.M.; Boegel, A.J.; Caufield, R.A.; Jovanovich, M.C.; Loftis, J.A.

    1993-04-01

    Halogenated and nonhalogenated hydrocarbons are components of contamination currently found in natural waterways, ground water, and soils as a result of spills and careless disposal practices. The development of proper treatment methodologies for the waste streams producing this environmental damage is now a subject of growing concern. A significant number of these waste stream compounds are chemically stable and are thus resistant to environmental degradation. Numerous researchers have investigated the use of ionizing radiation to decompose chlorinated hydrocarbons in diverse matrices and have proposed various free-radical-induced reaction mechanisms. In this paper, we present results of experimentally measured radiolytically induced decomposition using accelerator-generated bremsstrahlung sources and gamma radiation from cobalt-60. Data are presented on the radiolytically induced reduction in concentration of volatile organic compounds (VOCs) dissolved in water and in air, polychlorinated biphenyl (PCB) dissolved in oil, high explosives dissolved in ground water, and chemical weapon surrogates. The results of these studies suggest the potential use of ionizing radiation as a method of hazardous waste treatment

  1. Evaluation of the photon monitor backscatter in medical electron accelerators

    International Nuclear Information System (INIS)

    Zrenner, M.; Krieger, H.

    1999-01-01

    Background: Modern linear accelerators permit the use of irregular fields due to their flexible collimator systems with separately movable jaws or multileaf collimators. When using such irregular fields in the clinical practice output factors have to be corrected for enhanced backscatter to the dose monitor as compared with the conventional block shieldings. Methods: A method is presented to detect the monitor backscatter contributions to the output factor for irregular field settings. Results: The monitor backscatter factors have been measured using a telescopic device for 2 different treatment head geometries (Varian Clinac 2100C/D, General Electric Saturne 15) and for 3 photon radiation qualities (nominal energies X6, X18, X12). A method is introduced to calculate the monitor backscatter for arbitrary irregular treatment fields from the experimental data for square or rectangular fields. Conclusions: Besides the corrections for changes in phantom scatter and changes in the aperture, corrections for monitor backscatter have to be taken into account in many clinical cases. They can contribute up to more than 10% compared with the monitor values for free regular fields. (orig.) [de

  2. Post acceleration of a pseudospark-produced electron beam by an induction linac

    International Nuclear Information System (INIS)

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

    1992-01-01

    Recently, a high-brightness electron beam produced by a simple pseudospark device has been reported. Typically, the electron beam has a peak current of up to 1 kA, FWHM pulse duration of 30 ns, and an effective emittance of 4[ 2 > r2 > - 2] 1/2 = 100 mm-mrad. The normalized brightness of the beam is estimated to be on the order of 10 11 A/(m 2 -rad 2 ). This high-brightness beam may be immediately useful for high current accelerators and free-electron lasers if the beam energy can be boosted up. In this paper, the authors present preliminary results of the post acceleration of the electron beam by using an induction linac. The pseudospark device is modified by adding a trigger electrode in the hollow cavity of the cathode so that the generation of the electron beam is synchronized with the induction linac. A simple induction linac system of 25 kV, 1 kA, 50 ns pulse is being constructed. The electron beam, which is born in a low pressure gas, will be accelerated in the same background gas. This gas provides a sufficient ion channel for necessary focusing of this high-current density beam. Preliminary results on the beam current, energy spectrum, and emittance measurements of the post-accelerated beam will be presented

  3. Combined influence of azimuthal and axial magnetic fields on resonant electron acceleration in plasma

    Science.gov (United States)

    Singh, Arvinder; Rajput, Jyoti; Kant, Niti

    2017-11-01

    Resonant enhancement in electron acceleration due to a circularly polarized laser pulse in plasma, under the combined influence of external azimuthal and axial magnetic fields, is studied. We have investigated direct electron acceleration in plasma by employing a relativistic single particle simulation. The plasma is magnetized with an azimuthal magnetic field applied in the perpendicular plane and an axial magnetic field applied along the direction of laser beam propagation. Resonance takes place between electron and electric field of the laser pulse for the optimum value of the combined magnetic field, which supports electron acceleration to higher energies, up to the betatron resonance point. The optimum value of these magnetic fields is highly sensitive to laser initial intensity and laser initial spot size. The effects of laser intensity, initial spot size, and laser pulse duration are taken into consideration in optimizing the magnetic field for efficient electron acceleration. Higher electron energy gain, of the order of GeV, is observed by employing terawatt circularly polarized laser pulses in plasma under the influence of combined magnetic field of about 10 MG.

  4. Radiation decontamination of municipal wastewaters in pilot plant, using electron beam accelerator

    International Nuclear Information System (INIS)

    Ramirez, Trajano; Cueva, Ana Rosa; Munoz, Ricardo

    2001-01-01

    Full text: The design of a pilot plant for the treatment of municipal wastewaters with an electron accelerator is very important to study the effects of electron beam radiation on contaminated water in continuous flow. The pilot plant facility uses the Soviet linear electron accelerator ELU 6U, which operates on 8 MeV energy and a 5 kW power. The study consists of the optimization of decontamination and disinfection process of municipal wastewater with accelerated electrons, in continuous process, through the study of different variable effects of the irradiation process in the pilot plant on the physical-chemical and microbiological parameters of the wastewater flow rate, thickness and velocity of wastewater under the electron beam, inclination of the irradiation channel, aeration of the wastewater before and during the treatment process with the electron accelerator, ozone addition and double irradiation. The absorbed dose radiation by the wastewater was determined using a water calorimeter . The physical-chemical parameters of the wastewater studied were: pH, true color, apparent color, conductivity, solids content, chemical oxygen demand (COD) and biochemical oxygen demand (BODs), surfactants, phenols, oils and greases, nitrates, nitrites, nitrogen ammonia, cyanides, sulfides, sulfates, alkalinity, chromium, lead, cobalt, nicke and zinc. The microbiological parameters studied were: total microbial content, fecal coliforms, fungi and yeasts. Furthermore, all surviving microorganisms in the irradiated water were identified. (author)

  5. The electron edge of the low latitude boundary layer during accelerated flow events

    International Nuclear Information System (INIS)

    Gosling, J.T.; Thomsen, M.F.; Bame, S.J.; Onsager, T.G.; Russel, C.T.

    1990-01-01

    Magnetosheath plasma entering the Earth's magnetosphere to populate the low latitude boundary layer, LLBL, is often accelerated to speeds considerably greater than are observed in the adjacent magnetosheath. Measurements made during such accelerated flow events reveal separate electron and ion edges to the LLBL, with the electron edge being found earthward of the ion edge. Plasma electron velocity distributions observed at the earthward edge of the LLBL are often highly structured, exhibiting large asymmetries parallel and antiparallel, as well as perpendicular, to the local magnetic field. These features can consistently be interpreted as time-of-flight effects on recently reconnected field lines, and thus are strong evidence in support of the reconnection interpretation of accelerated plasma flow events

  6. Polarized Electron Beams for Nuclear Physics at the MIT Bates Accelerator Center

    CERN Document Server

    Farkhondeh, Manouchehr; Franklin, Wilbur; Ihloff, Ernie; McAllister, Brian; Milner, Richard; North, William; Tschalär, C; Tsentalovich, Evgeni; Wang, Defa; Wang, Dong; Wang, Fuhua; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

    2005-01-01

    The MIT Bates Accelerator Center is delivering highly polarized electron beams to its South Hall Ring for use in Nuclear Physics Experiments. Circulating electron currents in excess of 200 mA with polarization of 70% are scattered from a highly polarized, but very thin atomic beam source deuterium target. At the electron source a compact diode laser creates photoemission of quasi-CW mA pulses of polarized electrons at low duty factors from a strained GaAs photocathode. Refurbished RF transmitters provide power to the 2856 MHz linac, accelerating the beam to 850 MeV in two passes before injection into the South Hall Ring. In the ring a Siberian snake serves to maintain a high degree of longitudinal polarization at the BLAST scattering target. A Compton laser back-scattering polarimeter measures the electron beam polarization with a statistical acuracy of 6% every 15 minutes.

  7. 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)

  8. Electron emission from laser irradiating target normal sheath acceleration (TNSA)

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Cutroneo, Mariapompea

    2016-01-01

    Roč. 171, 9-10 (2016), s. 754-765 ISSN 1042-0150. [12th Workshop on European Collaboration for Higher Education and Research in Nuclear Engineering and Radiological Protection. Bologna, Catania, Milan, 30.05.2016-01.06.2016] R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : electron emission from plasma * TNSA * TOF * SiC * plastic scintillator * Thomson parabola spectrometer Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.443, year: 2016

  9. Enhancement of electron energy during vacuum laser acceleration in an inhomogeneous magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Saberi, H.; Maraghechi, B., E-mail: behrouz@aut.ac.ir [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

    2015-03-15

    In this paper, the effect of a stationary inhomogeneous magnetic field on the electron acceleration by a high intensity Gaussian laser pulse is investigated. A focused TEM (0,0) laser mode with linear polarization in the transverse x-direction that propagates along the z-axis is considered. The magnetic field is assumed to be stationary in time, but varies longitudinally in space. A linear spatial profile for the magnetic field is adopted. In other words, the axial magnetic field increases linearly in the z-direction up to an optimum point z{sub m} and then becomes constant with magnitude equal to that at z{sub m}. Three-dimensional single-particle simulations are performed to find the energy and trajectory of the electron. The electron rotates around and stays near the z-axis. It is shown that with a proper choice of the magnetic field parameters, the electron will be trapped at the focus of the laser pulse. Because of the cyclotron resonance, the electron receives enough energy from the laser fields to be accelerated to relativistic energies. Using numerical simulations, the criteria for optimum regime of the acceleration mechanism is found. With the optimized parameters, an electron initially at rest located at the origin achieves final energy of γ=802. The dynamics of a distribution of off-axis electrons are also investigated in which shows that high energy electrons with small energy and spatial spread can be obtained.

  10. Developments of electron accelerators for national economy in the AN SSSR SO IYaF

    International Nuclear Information System (INIS)

    Auslender, V.L.; Salimov, R.A.

    1979-01-01

    Described is the work aimed at developing ELV-type electrostatic electron accelerators with electron energies ranging from 0.4 to 1.5 MeV and an average beam current of up to 100 mA, and the ILU-6 electron linear accelerator with the energy from 0.5 to 2 MeV and an average beam current of up to 40 mA. To provide an output of a linearly scanned beam a special titanium window with dimension of 75 x 980 mm which provides transit of a current of up to 80 mA has been developed. To irradiate articles having a cylindrical shape two types of devices with a circular beam scanning have been developed. A device has been worked out for the output of concentrated beams into the atmosphere, in which the electron beam leaves the vacuum through a system of four ports having different diameters. Principles of operation and results of tests of these devices are briefly outlined. Examples of their application are given. More than ten tons of tubes have been irradiated on the ILU-6 accelerator to obtain thermal shrinkage, and this accelerator also served as the basis for developing a radiation sewage treatment plant. An annual economical effect is estimated at 2 million roubles per an accelerator

  11. Worldwide construction

    International Nuclear Information System (INIS)

    Williamson, M.

    1994-01-01

    The paper lists major construction projects in worldwide processing and pipelining, showing capacities, contractors, estimated costs, and time of construction. The lists are divided into refineries, petrochemical plants, sulfur recovery units, gas processing plants, pipelines, and related fuel facilities. This last classification includes cogeneration plants, coal liquefaction and gasification plants, biomass power plants, geothermal power plants, integrated coal gasification combined-cycle power plants, and a coal briquetting plant

  12. 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)

  13. 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.

  14. 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)

  15. Adaptation of an ion accelerator to a high voltage electron microscope

    International Nuclear Information System (INIS)

    Jesser, W.A.; Horton, J.A.; Scribner, L.L.

    1976-01-01

    The adaptation of a gas-source 200 kV ion accelerator to a 500 kV electron microscope was discussed as a means of simulating the CTR environment. The simultaneous accelerator microscope irradiation (SAMI) capability was demonstrated. Ion current densities of up to one milliamp/cm 2 and electron current densities near several amp/cm 2 are possible with the above system. In situ observations of blister and precipitate formation in 304 stainless steel at about 650 0 C were reported for 60 kV helium ion bombardment to a fluence of 3 x 10 19 ions cm -2 . (author)

  16. High-flux electron beams from laser wakefield accelerators driven by petawatt lasers

    Science.gov (United States)

    Zeng, Ming; Tesileanu, Ovidiu

    2017-07-01

    Laser wakefield accelerators (LWFAs) are considered to be one of the most competitive next-generation accelerator candidates. In this paper, we will study the potential high-flux electron beam production of an LWFA driven by petawatt-level laser pulses. In our three-dimensional particle-in-cell simulations, an optimal set of parameters gives ˜ 40 {nC} of charge with 2 {PW} laser power, thus ˜ 400 {kA} of instantaneous current if we assume the electron beam duration is 100 fs. This high flux and its secondary radiation are widely applicable in nuclear and QED physics, industrial imaging, medical and biological studies.

  17. A study on virtual source position for electron beams from a Mevatron MD linear accelerator

    International Nuclear Information System (INIS)

    Ravindran, B.P.

    1999-01-01

    The virtual source position (VSP) for electron beams of energies 5, 7, 9 10, 12 and 14 MeV and for the applicators (cones) available in the department have been measured for a Mevatron MD class linear accelerator. Different methods of obtaining the virtual source position for electron beams have been investigated in the present study. The results obtained have been compared with those of other workers. It is observed that the VSP is very much machine dependent and needs to be measured for each linear accelerator. The effect of shielding on virtual source position for the type of applicators available in the department has also been investigated. (author)

  18. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  19. Maintenance of the APS of an electron beam accelerator

    International Nuclear Information System (INIS)

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

    2008-12-01

    APS is a part of power supply system which provides the high voltage, high current to the anode of electron beam in the irradiation facility in KAERI. This APS had been used in turn-key base for 10 years, and frequently the Russian scientists had visited to repair this machine. In Summer the humid air had been supplied to dissipate the heat of APS. There is a big and high frequency noise around the transformer in the mutation room. So we stopped the irradiation works and analyzed and repaired the APS. The main course of the problem is the deterioration of IGBT and thyristors which are components of phase controller. We replaced this by new one and APS is now operating well

  20. MRI Linear accelerators : impact of the electron return effect

    International Nuclear Information System (INIS)

    Oborn, B.M.; Butson, M.J.; Metcalfe, P.E.; Rosenfeld, A.B.

    2010-01-01

    Full text: Recently there has been much interest in the development of an MRI-Linac for providing live-time, superior quality, imag guided radiotherapy. In current prototypes the magnetic field is transverse to the beam direction [1,2]. This leads to some undesirable dosimetry changes. One important change is the electron return effect (ERE) acting on the skin: electrons which leave a patient surface are forced to return and deposit dose locally [3, 4, 5]. The objective of this study is to characterize the ERE using Monte Carlo methods so that it can be accounted for in patient dose planning. High-resolution Geant4 Monte Carlo simulations have been performed to study the skin dose changes caused by the ERE. A Yarian 6 MY beam is modeled in transverse B-fields between 0-3 T. The effect of surface orientation is also studied, as well as the use of exit bolus for potentially lowering the effect of the ERE. The ERE causes significant skin dose increases on both the beam entry and exit surfaces. Surface orientation is also significant, leading to many arrangements with excessive skin dose due to the directional nature of the ERE. On the other hand this directional nature of the ERE can be combined with the surface orientation to minimize the skin dose changes. Conclusions The ERE gives rise to considerable skin dose increases in transverse-field MRI-linac designs. The results of this study how ever also show how these effects can be minimized if careful planning is performed as well as the use of exit bolus in some cases.

  1. Radiosensitivity of chlorella after medium energy accelerated electron irradiation; Radiosensibilite des chlorelles aux electrons acceleres de moyenne energie

    Energy Technology Data Exchange (ETDEWEB)

    Roux, J.C. [commissariat a L' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1966-06-01

    The survival curves (capability of multiplication) of chlorella pyrenoidosa after irradiations can be used for soft electrons (0.65 and 1 MeV), hence penetrating into only 2 to 4 millimeters of water: the algae are laying on porous membranes and the doses are calculated from the power of the electron beam measured by the electric current on a metallic target or by Fricke's dosimetry. With these techniques, it is showed and discussed the part of anoxia in the radioprotection (magnitude or reduction of the dose calculated from the slope of survival curves: 2.5 ) that is more important than the restoration studied by the fractionation of the dose. The 0.65 and 1 MeV electrons have a biologic effect lesser than 180 keV X-rays (RBE - relative biological efficiency - calculated on the slope of survival curves is 0.92 in aerated irradiation, 0.56 in the deoxygenated irradiation). (author) [French] Les courbes de survie clonale (capacite de multiplication) de chlorella pyrenoidosa apres irradiation sont realisables meme avec des electrons peu energetiques (0.65 et 1 MeV), donc peu penetrants, par l'irradiation d'algues deposees sur membrane filtrante et grace au calcul de la dose a partir de l'energie du faisceau mesure par le courant que celui-ci cree dans une cible metallique ou par dosimetrie de Fricke. Par ces techniques, on a montre et discute le role de l'anoxie dans la radioprotection des chlorelles (facteur de reduction de la dose calcule sur la pente des courbes de survie de 2.5) qui est plus important que le pouvoir de restauration etudie par le fractionnement de la dose. Les electrons utilises ont un effet biologique moins grand que les rayons X de 180 keV (l'efficacite biologique relative - EBR - calculee sur la pente des courbes de survie est de 0.9 en presence d'air, 0.6 en presence d'azote)

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

    Directory of Open Access Journals (Sweden)

    T. C. Marshall

    2001-12-01

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

  3. Theoretical progresses on electron and ion acceleration and relativistic short-pulse generation at SIOM

    International Nuclear Information System (INIS)

    Baifei Shen

    2010-01-01

    Complete text of publication follows. The triggering of wave-breaking in a three-dimensional laser plasma wake (bubble) with a nanowire is investigated. The Coulomb potential from the wire is used to disturb the wake field to initialize the wave-breaking. Controlled electron acceleration in the bubble regime is controlled by optimizing the plasma density. The origin of beam disparity in emittance and betatron oscillation orbits, in and out of the polarization plane of the drive laser of laser-plasma accelerators, is explained in terms of betatron oscillation driven by the laser field with simulation and a simple model. Proton trapping and acceleration by an electron bubble-channel structure in high-intensity laser interaction with high density plasma is investigated by using three-dimensional particle-in-cell simulations. It is shown that protons can be trapped, bunched, and efficiently accelerated for appropriate laser intensity and plasma density, and the proton acceleration is enhanced if the plasma consists mainly of heavier ions such as tritium. Theory and simulation of ion acceleration with electrostatic shock is given in detail. Electrostatic shock driven by linearly and circularly polarized laser pulse are compared. Multi stage shock acceleration for ultra thin foils is used to increase the efficiency of laser acceleration. The effect of plasma temperature of laser intensity is discussed. A sandwich target design with a thin compound ion layer between two light-ion layers and a micro-structured target design are proposed for obtaining efficiently monoenergetic heavy-ion beams. The foil thickness for light pressure acceleration is studied. Quasi-single cycle relativistic laser pulse is generated by laser-foil interaction.

  4. Controlled Electron Injection into Plasma Accelerators and SpaceCharge Estimates

    Energy Technology Data Exchange (ETDEWEB)

    Fubiani, Gwenael G.J. [Univ. of California, Berkeley, CA (United States)

    2005-09-01

    Plasma based accelerators are capable of producing electron sources which are ultra-compact (a few microns) and high energies (up to hundreds of MeVs) in much shorter distances than conventional accelerators. This is due to the large longitudinal electric field that can be excited without the limitation of breakdown as in RF structures.The characteristic scale length of the accelerating field is the plasma wavelength and for typical densities ranging from 1018 - 1019 cm-3, the accelerating fields and scale length can hence be on the order of 10-100GV/m and 10-40 μm, respectively. The production of quasimonoenergetic beams was recently obtained in a regime relying on self-trapping of background plasma electrons, using a single laser pulse for wakefield generation. In this dissertation, we study the controlled injection via the beating of two lasers (the pump laser pulse creating the plasma wave and a second beam being propagated in opposite direction) which induce a localized injection of background plasma electrons. The aim of this dissertation is to describe in detail the physics of optical injection using two lasers, the characteristics of the electron beams produced (the micrometer scale plasma wavelength can result in femtosecond and even attosecond bunches) as well as a concise estimate of the effects of space charge on the dynamics of an ultra-dense electron bunch with a large energy spread.

  5. Proceedings of the FNCA 2004 workshop on application of electron accelerator. EB treatment of flue gases

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Kume, Tamikazu

    2005-06-01

    '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). The 2004 workshop was jointly organized by China Atomic Energy Authority (CAEA), Institute of Modern Physics/Chinese Academy of Sciences(IMP-CAS) and Japan Atomic Energy Research Institute (JAERI). It was held at Prime Hotel, Beijing, China from 6 to 10 September 2004. The Workshop was attended by 28 experts on application of electron accelerator from each of the participating countries, i.e., China, Indonesia, Korea, Malaysia, The Philippines, Thailand and Vietnam, and 10 participants from Japan. On the first day, a National Executive Management Seminar on Application of Electron Accelerator was held and attended by 67 participants. Total of 20 papers including Seminar lectures, invited papers on flue gas treatment by electron beam, and country reports on EB irradiation system were presented. The major areas of interest of FNCA member states for cooperation were identified for application of low energy electron accelerator as liquid (natural polymer, wastewater), solid (hydrogel, thin film) and gases (flue gas). Based on the proposal from the participating countries, discussions were carried out to re-formulate the work plan of the project for three years until FY 2005. It was agreed the FNCA 2005 workshop on EB treatment of wastewater will be held in Korea. All manuscripts submitted by every speaker were included in the proceedings. The 20 of the presented papers are indexed individually. (J.P.N.)

  6. Characteristics of electron ponderomotive acceleration by a laser pulse in vacuum

    International Nuclear Information System (INIS)

    Lin, D; Kong, Q; Chen, Z; Wang, P X; Ho, Y K

    2008-01-01

    The ponderomotive acceleration scenario (PAS) for slow-electron acceleration by an intense laser pulse has been studied in detail using three-dimensional test-particle simulations. The relativistic Newton-Lorentz equation has been solved numerically for a linearly polarized laser. The results show that the PAS can accelerate slow electrons to an energy close to 1 MeV for a laser intensity a 0 = 3 (around 10 19 W cm -2 for a Ti : sapphire laser) and 24 MeV for a 0 = 20. These data are consistent with the experimental observation. The net gain comes from an asymmetry in the fields experienced by the electron during its acceleration and deceleration stages. It is found that electrons are scattered isotropically in the transverse direction for moderate laser intensity. The output bunches exhibit relatively wide angular and energy dispersions. We have also discussed an interesting bifurcation phenomenon in the energy-angle correlation spectra. According to our simulations, the maximal electron-energy gain in the PAS regime is approximately proportional to the laser intensity and the laser beam width and inversely proportional to the laser pulse duration. Physical interpretations based on the ponderomotive potential model as well as Lorentz-Newton force analyses are presented

  7. Proceedings of the FNCA 2003 workshop on application of electron accelerator. Radiation system for thin film

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Kume, Tamikazu

    2004-06-01

    '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 co-hosted by Malaysian Institute for Nuclear Technology Research (MINT) and Japan Atomic Energy Research Institute (JAERI). It was held at the Legend Hotel, Kuala Lumpur, Malaysia from 18 to 22 August 2003. The Workshop was attended by 28 experts on application of electron accelerator from each of the participating countries, i.e., China, Indonesia, Korea, Malaysia, The Philippines, Thailand and Vietnam, and 5 participants from Japan. On the first day, a National Executive Management Seminar on Application of Electron Accelerator was held and attended by 87 participants. Total of 19 papers including Seminar lectures, invited papers on film treatment by electron beam, and country reports on EB irradiation system were presented. The major areas of interest of FNCA member states for cooperation were identified for application of low energy electron accelerator as liquid, thin film and granules. The flue gas and wastewater treatments were added to the above major areas. Based on the proposal from the participating countries, discussions were carried out to re-formulate the work plan of the project for three years until FY 2004. All manuscripts submitted by every speaker were included in the proceedings. The 19 of the presented papers are indexed individually. (J.P.N.)

  8. Research on heightening quality of free electron laser using superconducting linear accelerator

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    1996-01-01

    In this paper, the superconducting high frequency linear accelerator technology using low temperature superconductor is introduced, and its application to the heightening of quality of free electron laser is discussed. The high frequency application of superconductivity is a relatively new technology, and the first superconducting high frequency linear accelerator was made at the middle of 1960s. The invention of free electron laser and the development so far are described. In free electron laser, the variation of wavelength, high efficiency and high power output are possible as compared with conventional type lasers. The price and the size are two demerits of free electron laser that remain to the last. In Japan Atomic Energy Research Institute, the adjustment experiment is carried out for the prototype free electron laser. About this prototype, injection system, superconducting accelerator, helium refrigerator, whole solid element high frequency power source, control system, electron beam transport system, undulator system and optical resonator are described. The application of high mean power output free electron laser and its future are discussed. (K.I.)

  9. Calibration of a silicon semiconductor detecter using a 2 MeV electron accelerator beam

    International Nuclear Information System (INIS)

    Fleurot, N.; Gouard, P.; Mazataud, E.; Nail, M.; Savy, C.; Bayer, C.; Cauchois, Y.; Kherouf, R.; Mathieu, D.

    1981-01-01

    This paper describes the current mode calibration, carried out on a 2 MeV electron accelerator, of PIN detectors involved in electron spectrum measurements for laser-matter interaction experiments. A theoretical analysis simulating the interaction between the incident electrons and the irradiated medium has been carried out using the FOTELEC code. It accounts well for the experimental results giving a reasonable value for the mean electron-hole pair formation energy when back-scattering corrections are included. This work provides the transfer function data required for a plasma diagnostic spectrometer. (orig.)

  10. Peculiarities of laser phase behavior associated with the accelerated electron in a chirped laser pulse

    International Nuclear Information System (INIS)

    Song, Q.; Wu, X. Y.; Wang, J. X.; Kawata, S.; Wang, P. X.

    2014-01-01

    In this paper, we qualitatively analyzed peculiarities of laser phase behavior associated with the accelerated electron in a chirped laser pulse. We unveiled the relationship between the changes in the orientation of the electron trajectory and the cusps in magnitude of the phase velocity of the optical field along the electron trajectory in a chirped laser pulse. We also explained how the chirp effect induced the singular point of the phase velocity. Finally, we discussed the phase velocity and phase witnessed by the electron in the particle's moving instantaneous frame

  11. Enabling More than Moore: Accelerated Reliability Testing and Risk Analysis for Advanced Electronics Packaging

    Science.gov (United States)

    Ghaffarian, Reza; Evans, John W.

    2014-01-01

    For five decades, the semiconductor industry has distinguished itself by the rapid pace of improvement in miniaturization of electronics products-Moore's Law. Now, scaling hits a brick wall, a paradigm shift. The industry roadmaps recognized the scaling limitation and project that packaging technologies will meet further miniaturization needs or ak.a "More than Moore". This paper presents packaging technology trends and accelerated reliability testing methods currently being practiced. Then, it presents industry status on key advanced electronic packages, factors affecting accelerated solder joint reliability of area array packages, and IPC/JEDEC/Mil specifications for characterizations of assemblies under accelerated thermal and mechanical loading. Finally, it presents an examples demonstrating how Accelerated Testing and Analysis have been effectively employed in the development of complex spacecraft thereby reducing risk. Quantitative assessments necessarily involve the mathematics of probability and statistics. In addition, accelerated tests need to be designed which consider the desired risk posture and schedule for particular project. Such assessments relieve risks without imposing additional costs. and constraints that are not value added for a particular mission. Furthermore, in the course of development of complex systems, variances and defects will inevitably present themselves and require a decision concerning their disposition, necessitating quantitative assessments. In summary, this paper presents a comprehensive view point, from technology to systems, including the benefits and impact of accelerated testing in offsetting risk.

  12. Electromagnetic computer simulations of collective ion acceleration by a relativistic electron beam

    International Nuclear Information System (INIS)

    Galvez, M.; Gisler, G.R.

    1988-01-01

    A 2.5 electromagnetic particle-in-cell computer code is used to study the collective ion acceleration when a relativistic electron beam is injected into a drift tube partially filled with cold neutral plasma. The simulations of this system reveals that the ions are subject to electrostatic acceleration by an electrostatic potential that forms behind the head of the beam. This electrostatic potential develops soon after the beam is injected into the drift tube, drifts with the beam, and eventually settles to a fixed position. At later times, this electrostatic potential becomes a virtual cathode. When the permanent position of the electrostatic potential is at the edge of the plasma or further up, then ions are accelerated forward and a unidirectional ion flow is obtained otherwise a bidirectional ion flow occurs. The ions that achieve higher energy are those which drift with the negative potential. When the plasma density is varied, the simulations show that optimum acceleration occurs when the density ratio between the beam (n b ) and the plasma (n o ) is unity. Simulations were carried out by changing the ion mass. The results of these simulations corroborate the hypothesis that the ion acceleration mechanism is purely electrostatic, so that the ion acceleration depends inversely on the charge particle mass. The simulations also show that the ion maximum energy increased logarithmically with the electron beam energy and proportional with the beam current

  13. Electron Lens Construction for the Integrable Optics Test Accelerator at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    McGee, Mike [Fermilab; Carlson, Kermit [Fermilab; Nobrega, Lucy [Fermilab; Stancari, Giulio [Fermilab; Valishev, Alexander [Fermilab

    2016-06-01

    The Integrable Optics Test Accelerator (IOTA) is proposed for operation at Fermilab. The goal of IOTA is to create practical nonlinear accelerator focusing systems with a large frequency spread and stable particle motion. The IOTA is a 40 m circumference, 150 MeV (e-), 2.5 MeV (p⁺) diagnostic test ring. Construction of an electron lens for IOTA is necessary for both electron and proton operation. Components required for the Electron Lens design include; a 0.8 T conventional water-cooled main solenoid, and magnetic bending and focusing elements. The foundation of the design relies on repurposing the Fermilab Tevatron Electron Lens II (TELII) gun and collector under ultra-high vacuum (UHV) conditions.

  14. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO 2 laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread (~1%) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO2 laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  15. Optimum point of acceleration of an electron inside the collisional plasma-filled elliptical waveguide

    Science.gov (United States)

    Hadad, M.; Torkiha-Esfhani, M.

    2015-04-01

    In this paper, the effect of the electron collision frequency with background ions on TMmr mode field components, the trajectory and the electron energy gain is studied. The field components of the TMmr mode in the elliptical waveguides are calculated. The ohmic heating for three different value of collision frequency calculated and the power losses is obtained. The deflection angle and acceleration gradient of an electron in the fields associated with a transverse magnetic (TM) wave propagating inside a elliptical waveguide for TMmr mode is studied. The relativistic momentum and energy equations for an electron are solved, which was injected initially along the propagation direction of the microwave. The results for TMmr mode are graphically represented. Finally, the optimum point of acceleration for the even mode TM 11 is obtained and it is shown that in a cross section of elliptical waveguide optimum point is center of ellipse.

  16. Cyclotron Acceleration of Relativistic Electrons through Landau Resonance with Obliquely Propagating Whistler Mode Chorus Emissions

    Science.gov (United States)

    Omura, Y.; Hsieh, Y. K.; Foster, J. C.; Erickson, P. J.; Kletzing, C.; Baker, D. N.

    2017-12-01

    A recent test particle simulation of obliquely propagating whistler mode wave-particle interaction [Hsieh and Omura, 2017] shows that the perpendicular wave electric field can play a significant role in trapping and accelerating relativistic electrons through Landau resonance. A further theoretical and numerical investigation verifies that there occurs nonlinear wave trapping of relativistic electrons by the nonlinear Lorentz force of the perpendicular wave magnetic field. An electron moving with a parallel velocity equal to the parallel phase velocity of an obliquely propagating wave basically see a stationary wave phase. Since the electron position is displaced from its gyrocenter by a distance ρ*sin(φ), where ρ is the gyroradius and φ is the gyrophase, the wave phase is modulated with the gyromotion, and the stationary wave fields as seen by the electron are expanded as series of Bessel functions Jn with phase variations n*φ. The J1 components of the wave electric and magnetic fields rotate in the right-hand direction with the gyrofrequency, and they can be in resonance with the electron undergoing the gyromotion, resulting in effective electron acceleration and pitch angle scattering. We have performed a subpacket analysis of chorus waveforms observed by the Van Allen Probes [Foster et al., 2017], and calculated the energy gain by the cyclotron acceleration through Landau resonance. We compare the efficiencies of accelerations by cyclotron and Landau resonances in typical events of rapid electron acceleration observed by the Van Allen Probes.References:[1] Hsieh, Y.-K., and Y. Omura (2017), Nonlinear dynamics of electrons interacting with oblique whistler mode chorus in the magnetosphere, J. Geophys. Res. Space Physics, 122, 675-694, doi:10.1002/2016JA023255.[2] Foster, J. C., P. J. Erickson, Y. Omura, D. N. Baker, C. A. Kletzing, and S. G. Claudepierre (2017), Van Allen Probes observations of prompt MeV radiation belt electron acceleration in nonlinear

  17. 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

  18. Quantitative Assessment of MeV Electron Acceleration in Non-Linear Interactions with VLF Chorus

    Science.gov (United States)

    Foster, J. C.; Erickson, P. J.; Omura, Y.; Baker, D. N.

    2016-12-01

    For occurrences of apparent rapid acceleration of radiation belt electrons to MeV energies at L 4, we examine the energy gained by seed electrons in non-linear (NL) interactions with VLF chorus rising tones. For the 17-18 March 2013 storm, observations of outer zone radiation belt electron populations were made with the magEIS and REPT instruments on Van Allen Probes A & B. These reveal that MeV electron fluxes at L=4.2 increased 10-fold in 30 min at the times of 30 - 100 keV electron injections during "substorm" dipolarizations. Simultaneous enhancements of VLF chorus were observed with the EMFISIS wave instruments. Three-axis burst mode observations of wave electric and magnetic fields have been used to investigate electron interactions with individual chorus rising tones on a sub millisecond time scale. Wave amplitudes at 2500 Hz were 1 nT (|B|) and 30 mV/m (|E|). Frequency - time characteristics of the observed chorus elements closely match those predicted by NL electron-chorus interaction modeling [Omura et al., 2015, J. Geophys. Res. Space Phys., 120, doi:10.1002/2015JA021563]. For seed electrons with initial energies 50 keV to 8 MeV, subpacket wave analysis was used to quantify resonant electron energy gain both by relativistic turning acceleration and by ultrarelativistic acceleration through nonlinear trapping by the chorus waves. Electrons with 1-2 MeV initial energy can experience a 300 keV total energy gain in NL interactions with a single 200 msec rising tone. Maximum energy gain from interaction with a single 10 msec subpacket was 100 keV for a 2 MeV seed electron. Examining a number of chorus elements at different locations during the rapid local acceleration of the radiation belt during this event, we conclude that seed electrons (100s keV - 5 MeV) can be accelerated by 50 keV - 500 keV in resonant NL interactions with a single VLF rising tone on a time scale of 10-100 msec.

  19. Dosimetry measurements during the commissioning of the GJ-2 electron accelerator

    DEFF Research Database (Denmark)

    Chosdu, R.; Hilmy, N.; Tobing, R.

    1995-01-01

    The GJ-2 electron accelerator (made in China, Sanghai) was put into operation at the Centre for Application of Isotopes and Radiation in Jakarta, Indonesia. In the course of the commissioning of the machine its main technical parameters were measured under different operating conditions. The elec......, ethanol-chlorobenzene dosimeter solution and FWT-60 film dosimeters. The applicability of polystyrene calorimeters designed for low electron energies at Ris phi National Laboratory was also tested for nominal dose determination....

  20. High power millimeter-wave free electron laser based on recirculating electrostatic accelerator

    International Nuclear Information System (INIS)

    Lee, Byung-Cheol; Kim, Sun-Kook; Jeong, Young-Uk; Cho, Sung-Oh; Lee, Jongmin

    1995-01-01

    Progress in the development of a high power, millimeter-wave free electron laser driven by a recirculating electrostatic accelerator is reported. The energy and the current of electron beam are 430 keV and 2 A, respectively. The expected average output power is above 10 kW at the wavelength of 3-10 mm. Minimizing of the beam loss is a key issue for CW operation of the FEL with high efficiency. (author)

  1. Coincidence set-up with a high duty-cycle, high energy electron accelerator

    International Nuclear Information System (INIS)

    Leconte, P.

    1981-01-01

    Important studies are now undertaken to develop continuous wave electron accelerators with energy ranging from 1 to 4 Gev. So very important effort must be now put on the development of the experimental set-up matching the performances expected from the electron beam. Major steps in the understanding of the nuclear systems will come from more and more exclusive experiments where well defined mechanisms will be selected

  2. Construction of an electron accelerator of 20 KeV: application in the polymeric study

    International Nuclear Information System (INIS)

    Sandonato, G.M.

    1983-01-01

    A low energy electron accelerator (maximum energy 20 KeV) is constructed. A black and white kinescope electron gun, with a single thermionic emitter was used as electron source. The energy of electron beam can be changed continuously from 0 to 20 KeV. The intensity of the current can be changed from a minimum of 10 -12 A to a maximum of 3 μA, and can be mantained contant in time after its value has been fixed. The irradiated area can be changed from a diameter of 1 milimeter to a maximum of 6 centimeter, by focalizing or defocalizing the image of electron beam. The final pressure reached in vacuum chambers was 10 -7 Torr. During operation the surface of cathode of electron gun is damaged by ion bombardeament. The degree of damage can be checked if the cathode image is focalized and examined on a luminescent screen. The accelerator was used to study electron irradiation effects in Teflon, employing the method of the split Faraday cup. Transient charging and discharging currents were measured. The average range of electrons of the electrons and the induced conductivity were determined. (Author) [pt

  3. High-current pulse electron accelerators based on stepped forming lines

    CERN Document Server

    Gordeev, V S; Filipov, V O; Petrov, A N; Gridasov, A P

    2001-01-01

    There presented is a brief review of I-3000, STRAUS, STRAUS-2 and LIA-10M accelerators produced in VNIEF over the period from 1981 to 1994. All the installations function in the mode of single pulses. Their distinction consists in using the systems of forming high-voltage pulses on the basis of stepped forming lines. Such installations formed of line sections of a similar electrical length with a stepped character of impedance variance provide a high efficiency and as a result of wave processes increase for a several time the output voltage as compared to the charge voltage of lines. The limiting energy of accelerated electrons for the created accelerators lies within the range from 2.3 to 25 MeV, beam current amplitude - from 20 to 50 kA, current pulse width at half-height - from 16 to 40 ns. The basic characteristics of each accelerator are presented.

  4. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    Science.gov (United States)

    Rodríguez-Fernández, Luis

    2010-09-01

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  5. Rf System For The Industrial Linear Electron Accelerator At Kaeri (daejeon, Korea)

    CERN Document Server

    Arbuzov, V S; Evtushenko, Yu A; Gorniker, E I; Kenjebulatov, E K; Kondakov, A A; Krutikhin, S A; Kurkin, G Ya; Motygin, S V; Osipov, V N; Petrov, V M; Pilan, Andrey M; Popov, A R; Shteinke, A M; Tribendis, A G

    2004-01-01

    Budker Institute of Nuclear Physics has developed and produced RF generators, feeder lines and a control system for an industrial linear electron accelerator at Korean Atomic Energy Research Institute (KAERI, Daejeon, Korea). The accelerator is based on two superconducting RF cavities produced by CERN. Design energy of the accelerator is 10 MeV and design beam current is 10 mA. A 2 MeV injector for the accelerator was made by BINP earlier. Two-channel RF system of the accelerator operates at the frequency of 352 MHz in CW mode. Each channel has two-stage tetrode amplifier with output power of 50 kW, 100 W transistor preamplifier and the control system. Both tetrode stages have identical design. TH571B tetrode tubes produced by THALES (France) are used. Output power of 45 kW per channel was reached in an equivalent resistive load. Now BINP continues development of the accelerator. The energy of 11 MeV and the beam current of 1.9 mA were achieved. The amplitude of accelerating voltage was 4.5 MV in each cavity,...

  6. Field-reversed bubble in deep plasma channels for high quality electron acceleration

    CERN Document Server

    Pukhov, A; Tueckmantel, T; Thomas, J; Yu, I; Kostyukov, Yu

    2014-01-01

    We study hollow plasma channels with smooth boundaries for laser-driven electron acceleration in the bubble regime. Contrary to the uniform plasma case, the laser forms no optical shock and no etching at the front. This increases the effective bubble phase velocity and energy gain. The longitudinal field has a plateau that allows for mono-energetic acceleration. We observe as low as 10−3 r.m.s. relative witness beam energy uncertainty in each cross-section and 0.3% total energy spread. By varying plasma density profile inside a deep channel, the bubble fields can be adjusted to balance the laser depletion and dephasing lengths. Bubble scaling laws for the deep channel are derived. Ultra-short pancake-like laser pulses lead to the highest energies of accelerated electrons per Joule of laser pulse energy.

  7. 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.)

  8. Operation Manual of the high voltage generator of the Pelletron electron accelerator

    International Nuclear Information System (INIS)

    Hernandez M, V.; Lopez V, H.; Alba P, U.

    1988-04-01

    The first version of a manual to operate the generator of high voltage generator of the Pelletron electron accelerator built in the ININ is presented. Since this generator has several components and/or elements, the one manual present has the purpose that the armed one or maintenance of anyone on its parts, is carried out in an orderly and efficient way. (Author)

  9. Quality control of virtual wedge in a linear electron accelerator with a computerized radiography system (CR)

    International Nuclear Information System (INIS)

    Ordiales, J. M.; Alvarez, F. J.; Falero, B.

    2011-01-01

    For quality control of the virtual wedge there are several systems on the market as arrays of detectors or ionization chambers, linear or 2D configuration, radiochromic films or digital imaging systems incorporated in electron linear accelerators (ALE ). The present work aims at implementing a system of Computed Radiography (CR) for a routine check of the virtual wedge.

  10. Experimental destruction of Ascarid ova in sewage sludge by accelerated electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Horak, Petr (Charles Univ., Prague (Czech Republic). Dept. of Parasitology)

    1994-04-01

    Aerobically-treated sewage sludge containing eggs of the nematode Ascaris suum was processed using accelerated electrons. After 8 weeks of incubation the morphological and developmental status of eggs was determined. Inhibition of development and the destruction of nematode embryos within eggs were observed at doses over 1.1 kGy. (author).

  11. Polyurethanes irradiation by accelerated electrons: molecular and supramolecular evolution, incidence on the extractable and biomedical implications

    International Nuclear Information System (INIS)

    Guignot, C.

    2002-11-01

    Face to the development of radiosterilization and polymers medical devices it was wished to study the behavior of polyurethanes under accelerated electrons in oxidizing atmosphere. This study has been made to reveal the physico chemical and organisational modifications of polyurethanes for a medical use. (N.C.)

  12. Study of cerenkov radiation. Production of γ rays by electron accelerators

    International Nuclear Information System (INIS)

    Bernard, J.

    1961-01-01

    This study is a critical comparison of the theories of Bremsstrahlung. Experimental results obtained by the production of γ radiation with electron accelerators are compared to the theoretical results in order to estimate the extent to which the various theories are valid. (author) [fr

  13. Electron Acceleration in a Turbulent Current Sheet - Comparison of GCA and HARHA Methods

    Czech Academy of Sciences Publication Activity Database

    Kramoliš, D.; Varady, Michal; Bárta, Miroslav

    2016-01-01

    Roč. 40, č. 1 (2016), s. 69-77 ISSN 1845-8319. [Hvar Astrophysical Colloquium /14./. Hvar, 26.09.2016-30.09.2016] R&D Projects: GA ČR(CZ) GA16-18495S Institutional support: RVO:67985815 Keywords : magnetic reconnection * current sheet * electron acceleration Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  14. Reducing NOx and SOx pollutants in an industrial units using electron accelerator

    Directory of Open Access Journals (Sweden)

    H Nouri

    2017-08-01

    Full Text Available Electron beam accelerators technology has made significant progress in environmental applications in recent years. Including some environmental applications of industrial accelerators, is clearing the air from oxides of nitrogen and sulfur(NOx , SOx produced by industrial facilities. Combustion  of coal, oil, natural gas and other gases that are produced in power plant, refineries and industrial factories, produce high extent of these oxides wshich exceed the limit in most cases. Clearing by irradiation involves adding amounts of ammonia to output gases and irradiation by Electron beam accelerators. Irradiation produces radicals that interact again with  NOx , SOx  and produced the related gases. Due to the ammonia, these acids transform into ammonium sulfate ((NH42SO4 and ammonium nitrate (NH4NO3 are precipitated by electrostatic precipitators, and are used as chemical fertilizer. Cosidering purification process of pollutant  gases by electron beam and the importance of electron accelerator in industrial plants that are polluting the environment in Iran, can be a suitable sollution for this environmental problem

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

    CERN Document Server

    Hansson, Martin; Ekerfelt, Henrik; Persson, Anna; Lundh, Olle

    2016-01-01

    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 p...

  16. Supersonic micro-jets and their application to few-cycle laser-driven electron acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Karl

    2009-07-23

    This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. The laser system employed in this work is a new development based on optical parametric chirped pulse amplification and is the only multi-TW few-cycle laser in the world. In the experiment, the laser beam is focused onto a supersonic helium gas jet which leads to the formation of a plasma channel. The laser pulse, having an intensity of 10{sup 19} W/cm{sup 2} propagates through the plasma with an electron density of 2 x 10{sup 19} cm{sup -3} and forms via a highly nonlinear interaction a strongly anharmonic plasma wave. The amplitude of the wave is so large that the wave breaks, thereby injecting electrons from the background plasma into the accelerating phase. The energy transfer from the laser pulse to the plasma is so strong that the maximum propagation distance is limited to the 100 m range. Therefore, gas jets specifically tuned to these requirements have to be employed. The properties of microscopic supersonic gas jets are thoroughly analyzed in this work. Based on numeric flow simulation, this study encompasses several extensive parameter studies that illuminate all relevant features of supersonic flows in microscopic gas nozzles. This allowed the optimized design of de Laval nozzles with exit diameters ranging from 150 {mu}m to 3 mm. The employment of these nozzles in the experiment greatly improved the electron beam quality. After these optimizations, the laser-driven electron accelerator now yields monoenergetic electron pulses with energies up to 50 MeV and charges between one and ten pC. The electron beam has a typical divergence of 5 mrad and comprises an energy spectrum that is virtually free from low energetic background. The electron pulse duration could not yet be determined experimentally but simulations point towards values in the range of 1 fs. The acceleration gradient is estimated from simulation and experiment to be approximately 0.5 TV/m. The

  17. Electron acceleration at Jupiter: input from cyclotron-resonant interaction with whistler-mode chorus waves

    Directory of Open Access Journals (Sweden)

    E. E. Woodfield

    2013-10-01

    Full Text Available Jupiter has the most intense radiation belts of all the outer planets. It is not yet known how electrons can be accelerated to energies of 10 MeV or more. It has been suggested that cyclotron-resonant wave-particle interactions by chorus waves could accelerate electrons to a few MeV near the orbit of Io. Here we use the chorus wave intensities observed by the Galileo spacecraft to calculate the changes in electron flux as a result of pitch angle and energy diffusion. We show that, when the bandwidth of the waves and its variation with L are taken into account, pitch angle and energy diffusion due to chorus waves is a factor of 8 larger at L-shells greater than 10 than previously shown. We have used the latitudinal wave intensity profile from Galileo data to model the time evolution of the electron flux using the British Antarctic Survey Radiation Belt (BAS model. This profile confines intense chorus waves near the magnetic equator with a peak intensity at ∼5° latitude. Electron fluxes in the BAS model increase by an order of magnitude for energies around 3 MeV. Extending our results to L = 14 shows that cyclotron-resonant interactions with chorus waves are equally important for electron acceleration beyond L = 10. These results suggest that there is significant electron acceleration by cyclotron-resonant interactions at Jupiter contributing to the creation of Jupiter's radiation belts and also increasing the range of L-shells over which this mechanism should be considered.

  18. Developing field emission electron sources based on ultrananocrystalline diamond for accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Baryshev, Sergey V.; Jing, Chunguang; Qiu, Jiaqi; Antipov, Sergey; Jabotinski, Vadim; Shao, Jiahang; Gai, Wei; Sumant, Anirudha V.

    2016-08-25

    Radiofrequency (RF) electron guns work by establishing an RF electromagnetic field inside a cavity having conducting walls. Electrons from a cathode are generated in the injector and immediately become accelerated by the RF electric field, and exit the gun as a series of electron bunches. Finding simple solutions for electron injection is a long standing problem. While energies of 30-50 MeV are achievable in linear accelerators (linacs), finding an electron source able to survive under MW electric loads and provide an average current of 1-10 mA is important. Meeting these requirements would open various linac applications for industry. The natural way to simplify and integrate RF injector architectures with the electron source would be to place the source directly into the RF cavity with no need for additional heaters/lasers. Euclid TechLabs in collaboration with Argonne National Lab are prototyping a family of highly effective field emission electron sources based on a nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) platform. Determined metrics suggest that our emitters are emissive enough to meet requirements for magnetized cooling at electron-ion colliders, linac-based radioisotope production and X-ray sterilization, and others.

  19. Electron Pre-acceleration at Nonrelativistic High-Mach-number Perpendicular Shocks

    Science.gov (United States)

    Bohdan, Artem; Niemiec, Jacek; Kobzar, Oleh; Pohl, Martin

    2017-09-01

    We perform particle-in-cell simulations of perpendicular nonrelativistic collisionless shocks to study electron heating and pre-acceleration for parameters that permit the extrapolation to the conditions at young supernova remnants. Our high-resolution large-scale numerical experiments sample a representative portion of the shock surface and demonstrate that the efficiency of electron injection is strongly modulated with the phase of the shock reformation. For plasmas with low and moderate temperature (plasma beta {β }{{p}}=5\\cdot {10}-4 and {β }{{p}}=0.5), we explore the nonlinear shock structure and electron pre-acceleration for various orientations of the large-scale magnetic field with respect to the simulation plane, while keeping it at 90° to the shock normal. Ion reflection off of the shock leads to the formation of magnetic filaments in the shock ramp, resulting from Weibel-type instabilities, and electrostatic Buneman modes in the shock foot. In all of the cases under study, the latter provides first-stage electron energization through the shock-surfing acceleration mechanism. The subsequent energization strongly depends on the field orientation and proceeds through adiabatic or second-order Fermi acceleration processes for configurations with the out-of-plane and in-plane field components, respectively. For strictly out-of-plane field, the fraction of suprathermal electrons is much higher than for other configurations, because only in this case are the Buneman modes fully captured by the 2D simulation grid. Shocks in plasma with moderate {β }{{p}} provide more efficient pre-acceleration. The relevance of our results to the physics of fully 3D systems is discussed.

  20. Transdusers for measuring currents and coordinates of subnanosecond accelerated electron beams

    International Nuclear Information System (INIS)

    Mocheshnikov, N.I.; Reprintsev, L.V.; Syumak, V.N.; Fedotov, I.F.

    1979-01-01

    Two types of monitors using eddy currents induced in the walls of an electronic channel by electron clusters have been developed. Monitors of the first type use, instead of the resistor belt, the input resistance of a wide-band transformer whose low-resistance input is connected to the break in the electron channel and the high-resistance output - to the output cable. The monitor is used in an electron storage ring. To increase the fast response of second-type monitors the brake in the electron channel is loaded with a low-resistance strip line. The signal from this line is taken near the place of its connection to the brake. The monitors are supposed to be used for resolution of the fine structure of a high-current electron linear accelerator beam. The achieved rise time constituted 0.15 - 0.2 ns

  1. Thermal electron acceleration by localized bursts of electric field in the radiation belts

    Science.gov (United States)

    Artemyev, A. V.; Agapitov, O. V.; Mozer, F.; Krasnoselskikh, V.

    2014-08-01

    In this paper we investigate the resonant interaction of thermal ˜10-100 eV electrons with a burst of electrostatic field that results in electron acceleration to kilovolt energies. This single burst contains a large parallel electric field of one sign and a much smaller, longer-lasting parallel field of the opposite sign. The Van Allen Probe spacecraft often observes clusters of spatially localized bursts in the Earth's outer radiation belts. These structures propagate mostly away from the geomagnetic equator and share properties of soliton-like nonlinear electron acoustic waves: a velocity of propagation is about the thermal velocity of cold electrons (˜3000-10,000 km/s), and a spatial scale of electric field localization along the field lines is about the Debye radius of hot electrons (˜5-30 km). We model the nonlinear resonant interaction of these electric field structures and cold background electrons.

  2. Relativistic electron acceleration by whistler-mode chorus emissions associated with substorms

    Science.gov (United States)

    Omura, Yoshiharu

    Whistler-mode chorus emissions are generated at the geomagnetic equator by injection of energetic electrons into the inner magnetosphere during geomagnetically disturbed periods of substorms[1]. We perform test particle simulations assuming whistler-mode chorus wave packets that are generated at the geomagnetic equator propagate away from the equator in both poleward directions. While electrons in the energy range 10 - 100 keV are primarily responsible for the generation of chorus waves through pitch angle diffusion into the loss cone, it has been found that a fraction of the higher-energy electrons from a few hundred keV to a few MeV are effectively accelerated by chorus due to special nonlinear trapping processes called relativistic turning acceleration (RTA)[2] and ultra-relativistic acceleration (URA)[3]. In the present study we confirm that the RTA and URA processes take place for a wave packet with variable frequency such as that occurring in a rising tone of chorus emissions. We study the efficiency of the RTA and URA processes for different particle energies. A Green's function method is used to describe the evolution of the particle energy distribution function. The RTA and URA processes due to chorus emissions create a high-energy tail in the electron energy distribution function[4]. The shape of the high-energy tail is determined by the distribution function of the seed electrons in the lower-energy range. The RTA and URA can accelerate electrons in a much shorter timescale than that estimated by quasi-linear diffusion theory, e.g., it typically takes tens of minutes to hours for a few keV seed electrons to be accelerated to energies of a few MeV by RTA and URA. References 1. Y. Omura, Y. Katoh, and D. Summers, Theory and simulation of the generation of whistlermode chorus, J. Geophys. Res., in press. 2. Y. Omura, N. Furuya, D. Summers, J Geophys. Res., Vol. 112, A06236, doi:10.1029/2006JA012243, 2007. 3. D. Summers and Y. Omura, Geophys. Res. Lett., 34

  3. Non-thermal particle acceleration in collisionless relativistic electron-proton reconnection

    Science.gov (United States)

    Werner, G. R.; Uzdensky, D. A.; Begelman, M. C.; Cerutti, B.; Nalewajko, K.

    2018-02-01

    Magnetic reconnection in relativistic collisionless plasmas can accelerate particles and power high-energy emission in various astrophysical systems. Whereas most previous studies focused on relativistic reconnection in pair plasmas, less attention has been paid to electron-ion plasma reconnection, expected in black hole accretion flows and relativistic jets. We report a comprehensive particle-in-cell numerical investigation of reconnection in an electron-ion plasma, spanning a wide range of ambient ion magnetizations σi, from the semirelativistic regime (ultrarelativistic electrons but non-relativistic ions, 10-3 ≪ σi ≪ 1) to the fully relativistic regime (both species are ultrarelativistic, σi ≫ 1). We investigate how the reconnection rate, electron and ion plasma flows, electric and magnetic field structures, electron/ion energy partitioning, and non-thermal particle acceleration depend on σi. Our key findings are: (1) the reconnection rate is about 0.1 of the Alfvénic rate across all regimes; (2) electrons can form concentrated moderately relativistic outflows even in the semirelativistic, small-σi regime; (3) while the released magnetic energy is partitioned equally between electrons and ions in the ultrarelativistic limit, the electron energy fraction declines gradually with decreased σi and asymptotes to about 0.25 in the semirelativistic regime; and (4) reconnection leads to efficient non-thermal electron acceleration with a σi-dependent power-law index, p(σ _i)˜eq const+0.7σ _i^{-1/2}. These findings are important for understanding black hole systems and lend support to semirelativistic reconnection models for powering non-thermal emission in blazar jets, offering a natural explanation for the spectral indices observed in these systems.

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

    CERN Document Server

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

    2016-01-01

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

  5. Electron Acceleration by Beating of Two Intense Cross-Focused Hollow Gaussian Laser Beams in Plasma

    Science.gov (United States)

    Mahmoud, Saleh T.; Gauniyal, Rakhi; Ahmad, Nafis; Rawat, Priyanka; Purohit, Gunjan

    2018-01-01

    This paper presents propagation of two cross-focused intense hollow Gaussian laser beams (HGBs) in collisionless plasma and its effect on the generation of electron plasma wave (EPW) and electron acceleration process, when relativistic and ponderomotive nonlinearities are simultaneously operative. Nonlinear differential equations have been set up for beamwidth of laser beams, power of generated EPW, and energy gain by electrons using WKB and paraxial approximations. Numerical simulations have been carried out to investigate the effect of typical laser-plasma parameters on the focusing of laser beams in plasmas and further its effect on power of excited EPW and acceleration of electrons. It is observed that focusing of two laser beams in plasma increases for higher order of hollow Gaussian beams, which significantly enhanced the power of generated EPW and energy gain. The amplitude of EPW and energy gain by electrons is found to enhance with an increase in the intensity of laser beams and plasma density. This study will be useful to plasma beat wave accelerator and in other applications requiring multiple laser beams. Supported by United Arab Emirates University for Financial under Grant No. UPAR (2014)-31S164

  6. CEBAF/SURA [Continuous Electron Beam Accelerator Facility]/[Southeastern Universities Research Association] 1988 summer workshop

    International Nuclear Information System (INIS)

    Gross, F.; Lightbody, J.

    1989-01-01

    This report contains papers from a summer workshop of the continuous electron beam accelerator facility. Some topics of these papers are: spectrometers; electron scattering from deuterons; relativistic correlations in nuclear matter; pion production on 3 He and 3 H; quantum electrodynamic processes in crystals; 12 C(e,e'p) x reaction; deuteron polarization tensor and relativistic spin rotation; electromagnetic excitation of nuclei; electron distortion and structure functions in (e,e'p) reactions; and reaction mechanism of 4 He(e,e'p) 3 H

  7. Two-Screen Method for Determining Electron Beam Energy and Deflection from Laser Wakefield Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, B B; Ross, J S; Tynan, G R; Divol, L; Glenzer, S H; Leurent, V; Palastro, J P; Ralph, J E; Froula, D H; Clayton, C E; Marsh, K A; Pak, A E; Wang, T L; Joshi, C

    2009-04-24

    Laser Wakefield Acceleration (LWFA) experiments have been performed at the Jupiter Laser Facility, Lawrence Livermore National Laboratory. In order to unambiguously determine the output electron beam energy and deflection angle at the plasma exit, we have implemented a two-screen electron spectrometer. This system is comprised of a dipole magnet followed by two image plates. By measuring the electron beam deviation from the laser axis on each plate, both the energy and deflection angle at the plasma exit are determined through the relativistic equation of motion.

  8. Implementation to spanish protocol of quality control of accelerators to daily control of electron beams

    International Nuclear Information System (INIS)

    Adaimi Hernandez, P.; Ramirez Ros, J. C.; Casa de Julian, M. A. de la; Clemente Gutierrez, F.; Cabello Murillo, E.; Diaz Fuente, R.; Ferrando Sanchez, A.

    2011-01-01

    A revised procedure for daily control of the electron beams to make measurements more meaningful physically, having a better reproducibility and more in line with the recommendations of the Spanish Protocol for Quality Control in Electron Linear Accelerators Clinical Use. The daily quality control beams of high energy electrons that had been done so far was the finding that the record of a series of measures (symmetry, uniformity, stability, energy, beam central dose) were within tolerance values established. The amendment is to check the beam quality by directly measuring changes in absorption depth at which the dose is reduced to half its maximum value, R50.

  9. Acceleration of electrons by high intensity laser radiation in a magnetic field

    OpenAIRE

    Melikian, Robert

    2013-01-01

    We consider the acceleration of electrons in vacuum by means of the circularly-polirized electromagnetic wave, propagating along a magnetic field. We show that the electron energy growth, when using ultra-short and ultra-intense laser pulses (10 ps, 10^{18} Bm/cm^2, CO_{2} laser) in the presence of a magnetic field, may reach up to the value 2,1 Gev. The growth of the electron energy is shown to increase proportionally with the increase of the laser intensity and the initial energy of the ele...

  10. On a possibility of using electron rings for heavy ion acceleration

    International Nuclear Information System (INIS)

    Aleksakhin, Yu.I.; Sarantsev, V.P.

    1985-01-01

    A variant of heavy ion collective accelerator, where every electron ring is multiply used, is described. The possibility to produce uranum ion beam intensity of 3x10 13 ions per second is shown. Electron ring, formed in the adhezator, is loaded with ions and kept in the ''waiting room'' for some time, necessary to attain the required charge degree. Later, the ring is transported to the region of dropping magnetic field and is accelerated. Then, the ring is transported to the region of rapidly rising magnetic field, where the condition of ion confinement is violated. The ions are ''shaken out'' of the ring. Slowing-down line serves for the ring return to the ''waiting room''. The time for attaining uranium ion charge degree Z=19 does not exceed 1 ms, so that at the operating frequency of electron ring generator 50 Hz each ring can be reused 20 times

  11. Characteristics of electron emission from PZT ferroelectric cathode under strong accelerating field

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Yasushi [Department of Energy Sciences, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama (Japan)]. E-mail: hayashi@es.titech.ac.jp; Hotta, Eiki [Department of Energy Sciences, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama (Japan); Flechtner, Donald [High Voltage Laboratory, Cornell University, Ithaca, NY (United States)

    2002-02-07

    We have studied emission characteristics of a PZT ferroelectric cathode under the influence of a strong accelerating field by varying the triggering conditions. The beam current pulse reveals a rising and a steady phase. In the rising phase, the time variation of the beam current is found to be linearly dependent on both the trigger voltage and the diode voltage at the time when the current starts. In the steady phase, field emission characteristics are observed. The results show that the diode voltage is not only accelerating the emitted electrons but also assisting the electron emission from the ferroelectric cathode. An empirical model is proposed and is found to yield a reasonable beam current pulse when the electric field on the surface of the cathode is uniformly distributed. It also provides us with a new possibility to diagnose the emission process of a ferroelectric electron gun. (author)

  12. First accelerator test of vacuum components with laser-engineered surfaces for electron-cloud mitigation

    Science.gov (United States)

    Calatroni, Sergio; Garcia-Tabares Valdivieso, Elisa; Neupert, Holger; Nistor, Valentin; Perez Fontenla, Ana Teresa; Taborelli, Mauro; Chiggiato, Paolo; Malyshev, Oleg; Valizadeh, Reza; Wackerow, Stefan; Zolotovskaya, Svetlana A.; Gillespie, W. Allan; Abdolvand, Amin

    2017-11-01

    Electron cloud mitigation is an essential requirement for high-intensity proton circular accelerators. Among other solutions, laser engineered surface structures (LESS) present the advantages of having potentially a very low secondary electron yield (SEY) and allowing simple scalability for mass production. Two copper liners with LESS have been manufactured and successfully tested by monitoring the electron cloud current in a dipole magnet in the SPS accelerator at CERN during the 2016 run. In this paper we report on these results as well as the detailed experiments carried out on samples—such as the SEY and topography studies—which led to an optimized treatment in view of the SPS test and future possible use in the HL-LHC.

  13. Results of adjustment of electron source for the LIU-30 accelerator

    International Nuclear Information System (INIS)

    Androsov, A.V.; Kladnitskij, V.S.; Platonov, S.L.; Shvets, V.A.

    1988-01-01

    A new design of an electron source (electron gun) for the LIU-30 accelerator is described. Unlike the earlier used ones it has been made as a separate unit connected via a special adapter with increasing pulsed 300 kW transformer constructed on the base of an accelerating section. Ferromagnetic screen of a special shape and antisolenoid placed behind the cathode in a hollow of an oil-filled insulator and switched on antiparallely to the main focusing solenoid permit to diminish the gun emittance by 10-15%due to zero magnetic field in the cathode region. Various electron-optical systems were tested and that one based on the Pierse gun in which the anode orifice was covered with a wire gauze with 2.5 mm cell was chosen. 3 refs.; 1 fig

  14. 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

  15. Energetic Electron Acceleration Observed by MMS in the Vicinity of an X-Line Crossing

    Science.gov (United States)

    Jaynes, A. N.; Turner, D. L.; Wilder, F. D.; Osmane, A.; Baker, D. N.; Blake, J. B.; Fennell, J. F.; Cohen, I. J.; Mauk, B. H.; Reeves, G. D.; hide

    2016-01-01

    During the first months of observations, the Magnetospheric Multiscale Fly's Eye Energetic Particle Spectrometer instrument has observed several instances of electron acceleration up to greater than 100 keV while in the vicinity of the dayside reconnection region. While particle acceleration associated with magnetic reconnection has been seen to occur up to these energies in the tail region, it had not yet been reported at the magnetopause. This study reports on observations of electron acceleration up to hundreds of keV that were recorded on 19 September 2015 around 1000 UT, in the midst of an X-line crossing. In the region surrounding the X-line, whistler-mode and broadband electrostatic waves were observed simultaneously with the appearance of highly energetic electrons which exhibited significant energization in the perpendicular direction. The mechanisms by which particles may be accelerated via reconnection-related processes are intrinsic to understanding particle dynamics among a wide range of spatial scales and plasma environments.

  16. Multilevel acceleration of scattering-source iterations with application to electron transport

    Directory of Open Access Journals (Sweden)

    Clif Drumm

    2017-09-01

    Full Text Available Acceleration/preconditioning strategies available in the SCEPTRE radiation transport code are described. A flexible transport synthetic acceleration (TSA algorithm that uses a low-order discrete-ordinates (SN or spherical-harmonics (PN solve to accelerate convergence of a high-order SN source-iteration (SI solve is described. Convergence of the low-order solves can be further accelerated by applying off-the-shelf incomplete-factorization or algebraic-multigrid methods. Also available is an algorithm that uses a generalized minimum residual (GMRES iterative method rather than SI for convergence, using a parallel sweep-based solver to build up a Krylov subspace. TSA has been applied as a preconditioner to accelerate the convergence of the GMRES iterations. The methods are applied to several problems involving electron transport and problems with artificial cross sections with large scattering ratios. These methods were compared and evaluated by considering material discontinuities and scattering anisotropy. Observed accelerations obtained are highly problem dependent, but speedup factors around 10 have been observed in typical applications.

  17. Whole body electron therapy using the Philips SL75/10 linear accelerator

    International Nuclear Information System (INIS)

    Mandelzweig, Y.; Yudelev, M.; Tatcher, M.

    1980-01-01

    Electrons produced by accelerators are always accompanied by Bremsstrahlung radiation generated by electron interactions with the accelerator exit window, monitor ionization chamber, collimator, etc. The ratio of the Bremsstrahlung x-rays to electrons depends on the design of the accelerator, beam energy and adjustment, and the treatment set-up. For the electron mode of the Philips SL75/10 linac, x-rays normally constitute 1-2% of the beam at a distance of 1 meter. While this is acceptable for conventional treatments when electrons are used for whole-body irradiation, the x-ray contamination can become excessive because of the degrading effects of the large treatment distances or scattering foils required to produce large fields. A whole body electron treatment method for the SL75/10 linac, with emphasis on the means employed to minimize the x-ray dose to the patient, is described. Measurements of the properties of the electro; beams and their x-ray components were made with the aid of a thin parallel plate ionization chamber, thermoluminescent dosimeters and films in various phantoms. From analysis of the results of the measurements a practical method for treating patients was developed. The method is based on multiple adjacent beams of 4 Mev electrons applied while the patient lies on the treatment couch at a distance of 150cm from the source. The method satisfies the clinical requirements with regard to the depth and uniformity of electron dose and the level of x-ray contamination. It is not necessary to modify the linac or to use any special devices when giving the treatment. (author)

  18. Energetic Electron Acceleration and Injection During Dipolarization Events in Mercury's Magnetotail

    Science.gov (United States)

    Dewey, Ryan M.; Slavin, James A.; Raines, Jim M.; Baker, Daniel N.; Lawrence, David J.

    2017-12-01

    Energetic particle bursts associated with dipolarization events within Mercury's magnetosphere were first observed by Mariner 10. The events appear analogous to particle injections accompanying dipolarization events at Earth. The Energetic Particle Spectrometer (3 s resolution) aboard MESSENGER determined the particle bursts are composed entirely of electrons with energies ≳ 300 keV. Here we use the Gamma-Ray Spectrometer high-time-resolution (10 ms) energetic electron measurements to examine the relationship between energetic electron injections and magnetic field dipolarization in Mercury's magnetotail. Between March 2013 and April 2015, we identify 2,976 electron burst events within Mercury's magnetotail, 538 of which are closely associated with dipolarization events. These dipolarizations are detected on the basis of their rapid ( 2 s) increase in the northward component of the tail magnetic field (ΔBz 30 nT), which typically persists for 10 s. Similar to those at Earth, we find that these dipolarizations appear to be low-entropy, depleted flux tubes convecting planetward following the collapse of the inner magnetotail. We find that electrons experience brief, yet intense, betatron and Fermi acceleration during these dipolarizations, reaching energies 130 keV and contributing to nightside precipitation. Thermal protons experience only modest betatron acceleration. While only 25% of energetic electron events in Mercury's magnetotail are directly associated with dipolarization, the remaining events are consistent with the Near-Mercury Neutral Line model of magnetotail injection and eastward drift about Mercury, finding that electrons may participate in Shabansky-like closed drifts about the planet. Magnetotail dipolarization may be the dominant source of energetic electron acceleration in Mercury's magnetosphere.

  19. On electron betatron motion and electron injection in laser wakefield accelerators

    Czech Academy of Sciences Publication Activity Database

    Matsuoka, T.; McGuffey, C.; Cummings, P.G.; Bulanov, S.S.; Chvykov, V.; Dollar, F.; Horovitz, Y.; Kalinchenko, Galina; Krushelnick, K.; Rousseau, P.; Thomas, A.G.R.; Yanovsky, V.; Maksimchuk, A.

    2015-01-01

    Roč. 56, č. 8 (2015), s. 1-8 ISSN 0741-3335 Institutional support: RVO:68378271 Keywords : accelerators * beams and electromagnetism * nuclear physics * plasma physics Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.404, year: 2015

  20. CAS - CERN Accelerator School: Free Electron Lasers and Energy Recovery Linacs

    CERN Document Server

    2018-01-01

    These proceedings collate lectures given at the course on Free Electron Lasers and Energy Recovery Linacs (FELsand ERLs), organised by the CERN Accelerator School (CAS). The course was held at the Hotel Scandic HamburgEmporio, Hamburg, Germany from 31 May to 10 June 2016, in collaboration with DESY. Following introductorylectures on radiation issues, the basic requirements on linear accelerators and ERLs are discussed. Undulators andthe process of seeding and lasing are then treated in some detail, followed by lectures on various beam dynamicsand controls issues.

  1. Design and construction of tetrode tube modulator for high power electron accelerator

    Directory of Open Access Journals (Sweden)

    A M Poursaleh

    2015-09-01

    Full Text Available In this paper, a high power tetrode tube (TH781-200kW, cw modulator is designed and implemented. This modulator is used for a part of RF system of the first Iranian high power electron accelerator project with similar structure to Rhodotron accelerator. Regarding to the level of sensitive and importance of TH781 tube the modulator system designed with high accuracy. So beside of power supplies design the control circuits for protection of the tube have been considered. The results of test and operation of this system that have been constructed in Iran for fist time is very satisfactory

  2. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

    Science.gov (United States)

    Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

    2013-01-01

    We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

  3. Design of a grating for studying Smith-Purcell radiation and electron acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1989-01-01

    We describe work on the design fo a diffracton grating which we intend to use for studying the production of Smith-Purcell radiation and the acceleration of electrons. We have developed computer codes based on the solution of the appropriate Maxwell's equations. A specific grating profile is given which is feasible to construct and which supports enhanced surface accelerating modes. We examine the possibility of using the Smith-Purcell effect to make a beam position monitor. copyright 1989 American Institute of Physics

  4. Design of a grating for studying Smith-Purcell radiation and electron acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1989-01-01

    We describe work on the design of a diffraction grating which we intend to use for studying the production of Smith-Purcell radiation and the acceleration of electrons. We have developed computer codes based on the solution of the appropriate Maxwell's equations. A specific grating profile is given which is feasible to construct and which supports enhanced surface accelerating modes. We examine the possibility of using the Smith-Purcell effect to make a beam position monitor. 13 refs., 10 figs., 2 tabs

  5. Observation of Electron Cloud Instabilities and Emittance Dilution at the Cornell Electron-Positron Storage Ring Test Accelerator

    International Nuclear Information System (INIS)

    Holtzapple, R.L.; Campbell, R.C.; McArdle, K.E.; Miller, M.I.; Totten, M.M.; Tucker, S.L.; Billing, M.G.; Dugan, G.F.; Ramirez, G.A.; Sonnad, K.G.; Williams, H.A.; Flanagan, J.; Palmer, M.A.

    2016-01-01

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnotics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions

  6. Observation of Electron Cloud Instabilities and Emittance Dilution at the Cornell Electron-Positron Storage Ring Test Accelerator

    Science.gov (United States)

    Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; Dugan, G. F.; Flanagan, J.; McArdle, K. E.; Miller, M. I.; Palmer, M. A.; Ramirez, G. A.; Sonnad, K. G.; Totten, M. M.; Tucker, S. L.; Williams, H. A.

    2016-04-01

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnotics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.

  7. New Statistical Multiparticle Approach to the Acceleration of Electrons by the Ion Field in Plasmas

    Directory of Open Access Journals (Sweden)

    Eugene Oks

    2010-01-01

    Full Text Available The phenomenon of the acceleration of the (perturbing electrons by the ion field (AEIF significantly reduces Stark widths and shifts in plasmas of relatively high densities and/or relatively low temperature. Our previous analytical calculations of the AEIF were based on the dynamical treatment: the starting point was the ion-microfield-caused changes of the trajectories and velocities of individual perturbing electrons. In the current paper, we employ a statistical approach: the starting point is the electron velocity distribution function modified by the ion microfield. The latter had been calculated by Romanovsky and Ebeling in the multiparticle description of the ion microfield. The result shows again the reduction of the electron Stark broadening. Thus two totally different analytical approaches (dynamical and statistical agree with each other and therefore disprove the corresponding recent fully-numerical simulations by Stambulchik et al. that claimed an increase of the electron Stark broadening.

  8. Proceedings of the workshop on photocathodes for polarized electron sources for accelerators

    International Nuclear Information System (INIS)

    Chatwell, M.; Clendenin, J.; Maruyama, T.; Schultz, D.

    1994-04-01

    Application of the GaAs polarized electron source to studies of surface magnetism; thermal stability of Cs on NES III-V-Photocathodes and its effect on quantum efficiency; AFEL accelerator; production and detection of SPIN polarized electrons; emittance measurements on a 100-keV beam from a GaAs photocathode electron gun; modern theory of photoemission and its applications to practical photocathodes; experimental studies of the charge limit phenomenon in GaAs photocathodes; new material for photoemission electron source; semiconductor alloy InGaAsP grown on GaAs substrate; NEA photocathode surface preparation; technology and physics; metalorganic chemical vapor deposition of GaAs-GaAsP spin-polarized photocathodes; development of photocathodes injectors for JLC-ATF; effect of radiation trapping on polarization of photoelectrons from semiconductors; and energy analysis of electrons emitted by a semiconductor photocathode

  9. Proceedings of the workshop on photocathodes for polarized electron sources for accelerators. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Chatwell, M.; Clendenin, J.; Maruyama, T.; Schultz, D. [eds.

    1994-04-01

    Application of the GaAs polarized electron source to studies of surface magnetism; thermal stability of Cs on NES III-V-Photocathodes and its effect on quantum efficiency; AFEL accelerator; production and detection of SPIN polarized electrons; emittance measurements on a 100-keV beam from a GaAs photocathode electron gun; modern theory of photoemission and its applications to practical photocathodes; experimental studies of the charge limit phenomenon in GaAs photocathodes; new material for photoemission electron source; semiconductor alloy InGaAsP grown on GaAs substrate; NEA photocathode surface preparation; technology and physics; metalorganic chemical vapor deposition of GaAs-GaAsP spin-polarized photocathodes; development of photocathodes injectors for JLC-ATF; effect of radiation trapping on polarization of photoelectrons from semiconductors; and energy analysis of electrons emitted by a semiconductor photocathode.

  10. Disinfection of sludge and waste-water by irradiation with electrons of low accelerating voltage

    International Nuclear Information System (INIS)

    Holl, P.; Schneider, H.

    1975-01-01

    From the point of view of hygiene, sewage sludge and water accumulating in ever increasing quantities, some of which is used in agriculture, represent a potential threat to the health of man and beast, as well as to the environment. It is known that these chains of infection can be broken up by ionizing radiation. The use of natural ionizing radiation or electron radiation with high accelerating voltage has not been accepted in practice because the radiation cannot be cut off and the investment cost for electron accelerators with an accelerating voltage of more than 1 MV is very high. These disadvantages may be overcome by using an electron accelerator with low accelerating voltage. Complex experiments have shown that it is not necessary to adapt the thickness of sewage sludge or water layer to the range of electrons. The layer to be irradiated may be much thicker if the substrate is revolved during irradiation. The advantages of this method are low accelerating voltage for the electrons and hence less costly radiation shielding, complete absorption of the radiated energy by the substrate, and low investment and operating cost. The sterilizing effect of the process can be explained by the secondary reactions that take place in the water, in addition to the primary reactions, when irradiating with high specific ionizing density. It is known from experiments carried out by Muenzner that water irradiated with electrons of high specific ionization density, when added to bacterial cultures, will destroy them. This is explained by the Weiss radical theory of water, with reaction products such as H 2 , O 2 and H 2 O 2 . The success of this process is shown by experiments with Escherichia coli, tap water to which Salmonella senftenberg were added, and by the content of Enterobacteriaceae in various sludges as a function of the irradiation period, as well as by the rate at which various invariable species of strongilide larvae, eggs of Ascaris suum, Fasciola hepatica and

  11. 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

  12. 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

  13. 3D electromagnetic simulation of spatial autoresonance acceleration of electron beams

    International Nuclear Information System (INIS)

    Dugar-Zhabon, V D; Orozco, E A; González, J D

    2016-01-01

    The results of full electromagnetic simulations of the electron beam acceleration by a TE 112 linear polarized electromagnetic field through Space Autoresonance Acceleration mechanism are presented. In the simulations, both the self-sustaned electric field and selfsustained magnetic field produced by the beam electrons are included into the elaborated 3D Particle in Cell code. In this system, the space profile of the magnetostatic field maintains the electron beams in the acceleration regime along their trajectories. The beam current density evolution is calculated applying the charge conservation method. The full magnetic field in the superparticle positions is found by employing the trilinear interpolation of the mesh node data. The relativistic Newton-Lorentz equation presented in the centered finite difference form is solved using the Boris algorithm that provides visualization of the beam electrons pathway and energy evolution. A comparison between the data obtained from the full electromagnetic simulations and the results derived from the motion equation depicted in an electrostatic approximation is carried out. It is found that the self-sustained magnetic field is a factor which improves the resonance phase conditions and reduces the beam energy spread. (paper)

  14. High voltage high brightness electron accelerators with MITL voltage adder coupled to foilless diodes

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Poukey, J.W.; Frost, C.A.; Shope, S.L.; Halbleib, J.A.; Turman, B.N.

    1993-01-01

    During the last ten years the authors have extensively studied the physics and operation of magnetically-immersed electron foilless diodes. Most of these sources were utilized as injectors to high current, high energy linear induction accelerators such as those of the RADLAC family. Recently they have experimentally and theoretically demonstrated that foilless diodes can be successfully coupled to self-magnetically insulated transmission line voltage adders to produce very small high brightness, high definition (no halo) electron beams. The RADLAC/SMILE experience opened the path to a new approach in high brightness, high energy induction accelerators. There is no beam drifting through the device. The voltage addition occurs in a center conductor, and the beam is created at the high voltage end in an applied magnetic field diode. This work was motivated by the remarkable success of the HERMES-III accelerator and the need to produce small radius, high energy, high current electron beams for air propagation studies and flash x-ray radiography. In this paper they present experimental results compared with analytical and numerical simulations in addition to design examples of devices that can produce multikiloamp electron beams of as high as 100 MV energies and radii as small as 1 mm

  15. THz cavities and injectors for compact electron acceleration using laser-driven THz sources

    Directory of Open Access Journals (Sweden)

    Moein Fakhari

    2017-04-01

    Full Text Available We present a design methodology for developing ultrasmall electron injectors and accelerators based on cascaded cavities excited by short multicycle THz pulses obtained from laser-driven THz generation schemes. Based on the developed concept for optimal coupling of the THz pulse, a THz electron injector and two accelerating stages are designed. The designed electron gun consists of a four cell cavity operating at 300 GHz and a door-knob waveguide to coaxial coupler. Moreover, special designs are proposed to mitigate the problem of thermal heat flow and induced mechanical stress to achieve a stable device. We demonstrated a gun based on cascaded cavities that is powered by only 1.1 mJ of THz energy in 300 cycles to accelerate electron bunches up to 250 keV. An additional two linac sections can be added with five and four cell cavities both operating at 300 GHz boosting the bunch energy up to 1.2 MeV using a 4-mJ THz pulse.

  16. Proceedings of the FNCA 2002 workshop on application of electron accelerator. Radiation system for liquid samples

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Kume, Tamikazu

    2003-10-01

    '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 16 to 20 December 2002. The attendants at the workshop were consisted of 13 experts on application of electron accelerator from each of the participating countries, i.e., China, Indonesia, Korea, Malaysia, the Philippines, Thailand and Vietnam, and 40 participants from Japan. A total of 18 papers including invited papers on liquid waste treatment by electron beam, reviews of the radiation systems, and designing and cost analysis of EB irradiation system were presented. The major areas of interest of FNCA countries for cooperation were identified for application of low energy electron accelerator as liquid, thin film and granules. The gas and wastewater treatments were added to the above major areas. Based on the proposal from the participating countries, discussions were carried out to re-formulate the work plan of the project for three years until FY 2004. All manuscripts submitted by every speaker were included in the proceedings. The 17 of the presented papers are indexed individually. (J.P.N.)

  17. Proceedings of the FNCA 2005 workshop on application of electron accelerator. EB treatment of wastewater

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Kume, Tamikazu

    2006-08-01

    '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), Japan. The 2005 workshop was jointly organized by the Ministry of Science and Technology (MOST), Korea, Korea Atomic Energy Research Institute and Japan Atomic Energy Agency (JAEA). It was held at the International Nuclear Technology and Education Center (INTEC/KAERI), Daejeon, Korea from 14 to 18 November 2005. The Workshop was attended by 32 experts on application of electron accelerator from each of the participating countries, i.e., China (1), Indonesia (1), Korea (18), Malaysia (2), Philippines (1), Thailand (1) and Vietnam (1), and 7 participants from Japan. On the first day, a National Executive Management Seminar on Application of Electron Accelerator was held and attended by 45 participants. Total of 20 papers including Seminar lectures, invited papers on wastewater treatment by electron beam, and country reports on EB irradiation system were presented. The major areas of interest of FNCA member states for cooperation were identified for application of low energy electron accelerator to liquids (natural polymer, wastewater), solids (hydrogel, thin film) and gases (flue gas). Based on the evaluation and proposal from the participating countries, discussions were carried out to re-formulate the work plan of the project on natural polymers and wastewater for three years until FY 2008. It was agreed the FNCA 2006 workshop on EB crosslinking of natural polymers would be held in Malaysia. All manuscripts submitted by every speaker were included in the proceedings. The 18 presented papers are indexed individually. (J.P.N.)

  18. Multichannel computerized control system of current pulses in LIU-30 electron accelerator

    CERN Document Server

    Gerasimov, A I; Kulgavchuk, V V; Pluzhnikov, A V

    2002-01-01

    In LIU-30 power linear pulsed induction electron accelerator (40 MeV, 10 kA, 25 ns) 288 radial lines with water insulation serve as energy accumulators and shapers of accelerating voltage pulses. The lines are charged simultaneously up to 500 kV using a system comprising 72 Arkadiev-Marx screened generators. To control parameter of synchronous pulses of charging current with up to 60 kA amplitude and 0.85 mu s duration in every of 72 charging circuits one applies a computer-aided system. Current pulse is recorded at output of every generator using the Rogowski coil signal from which via a cable line is transmitted to an analog-digital converter, is processed with 50 ns sampling and is recorded to a memory unit. Upon actuation of accelerator the signals are sequentially or selectively displayed and are compared with pulse typical shape

  19. Corkscrew Motion of an Electron Beam due to Coherent Variations in Accelerating Potentials

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-13

    Corkscrew motion results from the interaction of fluctuations of beam electron energy with accidental magnetic dipoles caused by misalignment of the beam transport solenoids. Corkscrew is a serious concern for high-current linear induction accelerators (LIA). A simple scaling law for corkscrew amplitude derived from a theory based on a constant-energy beam coasting through a uniform magnetic field has often been used to assess LIA vulnerability to this effect. We use a beam dynamics code to verify that this scaling also holds for an accelerated beam in a non-uniform magnetic field, as in a real accelerator. Results of simulations with this code are strikingly similar to measurements on one of the LIAs at Los Alamos National Laboratory.

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

    International Nuclear Information System (INIS)

    Alexander, K.F.; Hintze, W.

    1976-01-01

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

  1. Electron scattering and collimation system for a 12-MeV linear accelerator.

    Science.gov (United States)

    Bjarngard, B E; Piontek, R W; Svensson, G K

    1976-01-01

    The original scattering and collimation system for the Siemens Mevatron XII linear accelerator used a lead scattering foil and box-type plastic collimators. This arrangement achieves excellent field flatness by repeated electron scattering. The electrons reaching the patient are widely distributed in energy and direction. This has detrimental effects on the depth-dose curves: slower falloff and increased surface dose. We have developed an alternative system for this accelerator, designed to minimize electron scatter and improve the safety of patient setup. Primary-electron scatter occurs in the bending-magnet exit window. Field uniformity is accomplished with a flattener of thin aluminum discs of different diameters, piled concentrically. An adjustable electron collimator 25 cm from the patient limits beam size, and a final electron collimator, either a cutout from lead sheet or a custom-made collimator of Lipowitz's metal, in contact with the patient, define the area to be treated. This design results in lower surface dose, sharper dose falloff, bremsstrahlung contamination less than or equal to 1%, and a field flatness expressed by a homogeneity index greater than 0.8 for large fields. Since there is no mechanical connection between the machine and the final collimator, the safety aspects of the system are considerably improved.

  2. The Effect of Background Pressure on Electron Acceleration from Ultra-Intense Laser-Matter Interactions

    Science.gov (United States)

    Le, Manh; Ngirmang, Gregory; Orban, Chris; Morrison, John; Chowdhury, Enam; Roquemore, William

    2017-10-01

    We present two-dimensional particle-in-cell (PIC) simulations that investigate the role of background pressure on the acceleration of electrons from ultra intense laser interaction at normal incidence with liquid density ethylene glycol targets. The interaction was simulated at ten different pressures varying from 7.8 mTorr to 26 Torr. We calculated conversion efficiencies from the simulation results and plotted the efficiencies with respect to the background pressure. The results revealed that the laser to > 100 keV electron conversion efficiency remained flat around 0.35% from 7.8 mTorr to 1.2 Torr and increased exponentially from 1.2 Torr onward to about 1.47% at 26 Torr. Increasing the background pressure clearly has a dramatic effect on the acceleration of electrons from the target. We explain how electrostatic effects, in particular the neutralization of the target by the background plasma, allows electrons to escape more easily and that this effect is strengthened with higher densities. This work could facilitate the design of future experiments in increasing laser to electron conversion efficiency and generating substantial bursts of electrons with relativistic energies. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

  3. Acceleration of electrons in the vicinity of a lower hybrid waveguide array

    International Nuclear Information System (INIS)

    Fuchs, V.; Goniche, M.; Demers, Y.; Jacquet, P.; Mailloux, J.

    1996-01-01

    The interaction of tokamak plasma edge electrons with the electric near field generated by a lower hybrid slow wave antenna is studied. Antenna field spectra of interest for current drive and/or plasma heating have lobes at high-n parallel values (n parallel approx-gt 30) intense enough for resonant acceleration of the relatively cold (∼25 eV) edge electrons. For waveguide electric fields, typically around 3 kV/cm, the higher-order modes overlap in the phase-space [B. V. Chirikov, Phys. Rep. 52, 263 (1979)], so that electron global stochasticity is induced. For Tokamak de Varennes (TdeV) [Dacute ecoste et al., Phys. Plasmas 1, 1497 (1994)] conditions and for 90 degree waveguide phasing, the stochastic limit in the current drive direction is about 2 keV, determined by the last overlapping mode. The progress of electrons through accessible phase space is very efficient: the TdeV 32 waveguide array can accelerate the electrons to the possible limit. An area-preserving map is derived to study the electron dynamics. Surface-of-section plots fully confirm the resonant wave-particle nature of the interaction. copyright 1996 American Institute of Physics

  4. Neutron fluence in a 18 MeV Electron Accelerator for Therapy

    International Nuclear Information System (INIS)

    Paredes G, L.C.

    2001-01-01

    An investigation was made on the theoretical fundamentals for the determination of the neutron fluence in a linear electron accelerator for radiotherapy applications and the limit values of leakage neutron radiation established by guidelines and standards in radiation protection for these type of accelerators. This investigation includes the following parts: a) Exhaustive bibliographical review on the topics mentioned above, in order to combine and to update the necessary basic information to facilitate the understanding of this subject; b) Analysis of the accelerator operation and identification of its main components, specially in the accelerator head; c) Study of different types of targets and its materials for the Bremsstrahlung production which is based on the electron initial energy, the thickness of the target, and its angular distribution and energy, which influences in the neutron generation by means of the photonuclear and electro disintegration reactions; d) Analysis of the neutron yield based on the target type and its thickness, the energy of electrons and photons; e) Analysis of the neutron energy spectra generated in the accelerator head, inside and outside the treatment room; f) Study of the dosimetry fundamentals for neutron and photon mixed fields, the dosimeter selection criteria and standards applied for these applications, specially the Panasonic U D-809 thermoluminescent dosemeter and C R-39 nuclear track dosimeter; g) Theoretical calculation of the neutron yield using a simplified geometric model for the accelerator head with spherical cell, which considers the target, primary collimator, flattener filter, movable collimators and the head shielding as the main components for radiation production. The cases with W and Pb shielding for closed movable collimators and an irradiation field of 20 x 20 cm 2 were analyzed and, h) Experimental evaluation of the leakage neutron radiation from the patient and head planes, observing that the accelerator

  5. An accelerator scenario for a hard X-ray free electron laser combined with high energy electron radiography

    Science.gov (United States)

    Wei, Tao; Li, Yiding; Yang, Guojun; Pang, Jian; Li, Yuhui; Li, Peng; Pflueger, Joachim; He, Xiaozhong; Lu, Yaxin; Wang, Ke; Long, Jidong; Zhang, Linwen; Wu, Qiang

    2016-08-01

    In order to study the dynamic response of the material and the physical mechanism of fluid dynamics, an accelerator scenario which can be applied to both hard X-ray free electron laser and high energy electron radiography is proposed. This accelerator is mainly composed of a 12 GeV linac, an undulator branch and an eRad beamline. In order to characterize a sample’s dynamic behavior in situ and real-time with XFEL and eRad simultaneously, the linac should be capable of accelerating the two kinds of beam within the same operation mode. Combining in-vacuum and tapering techniques, the undulator branch can produce more than 1011 photons per pulse in 0.1% bandwidth at 42 keV. Finally, an eRad amplifying beamline with 1:10 ratio is proposed as an important complementary tool for the wider view field and density identification ability. Supported by China Academy of Engineering Physics (2014A0402016) and Institute of Fluid Physics (SFZ20140201)

  6. Electron-beam driven dielectric wakefield accelerator experiments in the terahertz regime

    Science.gov (United States)

    Andonian, Gerard

    2012-12-01

    In recent years, there has been rapid experimental progress on using the self-fields of electron beams to drive accelerating gradients in dielectric lined cavities. The extension to sub-mm scaled cavities, producing terahertz frequencies, has allowed an accessible region to study high-gradient structures in many advanced accelerator facilities. In this paper, we present a broad review of such results as they pertain to dielectric wakefield acceleration (DWA). Issues that are discussed include the examination of breakdown in such structures and materials, as well as studies of in-line spectra generated by coherent Cherenkov radiation, which, for appropriate geometries, produce narrowband, tunable terahertz radiation. We examine measurements of higher-order mode excitations in these structures, which provide a novel characterization method as well as a tunable source of terahertz radiation. We describe DWA measurements including wakefield mapping, selective resonant mode excitation, and observation of energy modulation and acceleration made possible by electron beam manipulation schemes, such as drive-witness, pulse-train, and ramped beam generation. We present alternate materials and geometries such as 1D and 3D photonic-like structures. Finally, we conclude with preliminary results from the initial DWA experimental runs at the SLAC FACET facility.

  7. Diverse Electron and Ion Acceleration Characteristics Observed Over Jupiter's Main Aurora

    Science.gov (United States)

    Mauk, B. H.; Haggerty, D. K.; Paranicas, C.; Clark, G.; Kollmann, P.; Rymer, A. M.; Peachey, J. M.; Bolton, S. J.; Levin, S. M.; Adriani, A.; Allegrini, F.; Bagenal, F.; Bonfond, B.; Connerney, J. E. P.; Ebert, R. W.; Gladstone, G. R.; Kurth, W. S.; McComas, D. J.; Ranquist, D.; Valek, P.

    2018-02-01

    Two new Juno-observed particle features of Jupiter's main aurora demonstrate substantial diversity of processes generating Jupiter's mysterious auroral emissions. It was previously speculated that sometimes-observed potential-driven aurora (up to 400 kV) can turn into broadband stochastic acceleration (dominating at Jupiter) by means of instability. Here direct evidence for such a process is revealed with a "mono-energetic" electron inverted-V rising in energy to 200 keV, transforming into a region of broadband acceleration with downward energy fluxes tripling to 3,000 mW/m2, and then transforming back into a mono-energetic structure ramping down from 200 keV. But a second feature of interest observed nearby is unlikely to have operated in the same way. Here a downward accelerated proton inverted-V, with inferred potentials to 300-400 kV, occurred simultaneously with downward accelerated broadband electrons with downward energy fluxes as high as any observed ( 3,000 mW/m2). This latter feature has no known precedent with Earth auroral observations.

  8. Design and validation of an accelerator for an ultracold electron source

    Directory of Open Access Journals (Sweden)

    G. Taban

    2008-05-01

    Full Text Available We describe here a specially designed accelerator structure and a pulsed power supply that are essential parts of a high brightness cold atoms-based electron source. The accelerator structure allows a magneto-optical atom trap to be operated inside of it, and also transmits subnanosecond electric field pulses. The power supply produces high voltage pulses up to 30 kV, with a rise time of up to 30 ns. The resulting electric field inside the structure is characterized with an electro-optic measurement and with an ion time-of-flight experiment. Simulations predict that 100 fC electron bunches, generated from trapped atoms inside the structure, reach an emittance of 0.04 mm mrad and a bunch length of 80 ps.

  9. Particle-in-cell simulations of plasma accelerators and electron-neutral collisions

    Directory of Open Access Journals (Sweden)

    David L. Bruhwiler

    2001-10-01

    Full Text Available We present 2D simulations of both beam-driven and laser-driven plasma wakefield accelerators, using the object-oriented particle-in-cell code XOOPIC, which is time explicit, fully electromagnetic, and capable of running on massively parallel supercomputers. Simulations of laser-driven wakefields with low \\(∼10^{16} W/cm^{2}\\ and high \\(∼10^{18} W/cm^{2}\\ peak intensity laser pulses are conducted in slab geometry, showing agreement with theory and fluid simulations. Simulations of the E-157 beam wakefield experiment at the Stanford Linear Accelerator Center, in which a 30 GeV electron beam passes through 1 m of preionized lithium plasma, are conducted in cylindrical geometry, obtaining good agreement with previous work. We briefly describe some of the more significant modifications to XOOPIC required by this work, and summarize the issues relevant to modeling relativistic electron-neutral collisions in a particle-in-cell code.

  10. Ion and relativistic electron acceleration by Alfven and whistler turbulence in solar flares

    Science.gov (United States)

    Miller, James A.; Ramaty, Reuven

    1987-01-01

    A model is proposed in which turbulent Alfven and whistler waves simultaneously produce the proton and electron spectra implied by the gamma-ray observations noted during the impulsive phase of the June 3, 1982 flare. The results demonstrate that protons can be accelerated to several GeV in less than about 10 sec by Alfven turbulence whose energy density is greater than a few erg/cu cm. It is also found that electrons may be accelerated to tens of MeV on similar time scales by whistler and Alfven turbulence. A lower limit on the energy density of the Alfven turbulence is obtained which is small compared to the total magnetic energy density.

  11. Interstellar electron density fluctuations due to cosmic-ray acceleration at supernova remnant shock waves

    International Nuclear Information System (INIS)

    Max, C.E.; Zachary, A.; Arons, J.

    1988-01-01

    We have performed computer simulations to investigate whether sizeable electron density fluctuations might be produced in the process of cosmic-ray acceleration at supernova remnant shock waves. The hypothesis is the following: Cosmic-ray acceleration via a Fermi I mechanism leads to large-amplitude Alfven waves upstream of a supernova remnant shock wave. If the Alfven waves reach a large enough amplitude, they can drive sound waves in the interstellar medium. The fluctuations in the electron density due to these sound waves will then contribute to the observed interstellar scintillation. Our simulations suggest that this mechanism may be a plausible one. Issues remaining to be addressed include the resulting filling factor, and the integrated strength C 2 /sub n/ to be expected for the turbulence

  12. Van Allen Probes observations of prompt MeV radiation belt electron acceleration in nonlinear interactions with VLF chorus

    Science.gov (United States)

    Foster, J. C.; Erickson, P. J.; Omura, Y.; Baker, D. N.; Kletzing, C. A.; Claudepierre, S. G.

    2017-01-01

    Prompt recovery of MeV (millions of electron Volts) electron populations in the poststorm core of the outer terrestrial radiation belt involves local acceleration of a seed population of energetic electrons in interactions with VLF chorus waves. Electron interactions during the generation of VLF rising tones are strongly nonlinear, such that a fraction of the relativistic electrons at resonant energies are trapped by waves, leading to significant nonadiabatic energy exchange. Through detailed examination of VLF chorus and electron fluxes observed by Van Allen Probes, we investigate the efficiency of nonlinear processes for acceleration of electrons to MeV energies. We find through subpacket analysis of chorus waveforms that electrons with initial energy of hundreds of keV to 3 MeV can be accelerated by 50 keV-200 keV in resonant interactions with a single VLF rising tone on a time scale of 10-100 ms.

  13. A parametric model to describe neutron spectra around high-energy electron accelerators and its application in neutron spectrometry with Bonner Spheres

    International Nuclear Information System (INIS)

    Bedogni, Roberto; Pelliccioni, Maurizio; Esposito, Adolfo

    2010-01-01

    Due to the increased interest of the scientific community in the applications of synchrotron light, there is an increasing demand of high-energy electron facilities, testified by the construction of several new facilities worldwide. The radiation protection around such facilities requires accurate experimental methods to determine the dose due to prompt radiation fields. Neutron fields, in particular, are the most complex to measure, because they extend in energy from thermal (10 -8 MeV) up to hundreds MeV and because the responses of dosemeters and survey meters usually have large energy dependence. The Bonner Spheres Spectrometer (BSS) is in practice the only instrument able to respond over the whole energy range of interest, and for this reason it is frequently used to derive neutron spectra and dosimetric quantities in accelerator workplaces. Nevertheless, complex unfolding algorithms are needed to derive the neutron spectra from the experimental BSS data. This paper presents a parametric model specially developed for the unfolding of the experimental data measured with BSS around high-energy electron accelerators. The work consists of the following stages: (1) Generation with the FLUKA code, of a set of neutron spectra representing the radiation environment around accelerators with different electron energies; (2) formulation of a parametric model able to describe these spectra, with particular attention to the high-energy component (>10 MeV), which may be responsible for a large part of the dose in workplaces; and (3) implementation of this model in an existing unfolding code.

  14. A parametric model to describe neutron spectra around high-energy electron accelerators and its application in neutron spectrometry with Bonner Spheres

    Science.gov (United States)

    Bedogni, Roberto; Pelliccioni, Maurizio; Esposito, Adolfo

    2010-03-01

    Due to the increased interest of the scientific community in the applications of synchrotron light, there is an increasing demand of high-energy electron facilities, testified by the construction of several new facilities worldwide. The radiation protection around such facilities requires accurate experimental methods to determine the dose due to prompt radiation fields. Neutron fields, in particular, are the most complex to measure, because they extend in energy from thermal (10 -8 MeV) up to hundreds MeV and because the responses of dosemeters and survey meters usually have large energy dependence. The Bonner Spheres Spectrometer (BSS) is in practice the only instrument able to respond over the whole energy range of interest, and for this reason it is frequently used to derive neutron spectra and dosimetric quantities in accelerator workplaces. Nevertheless, complex unfolding algorithms are needed to derive the neutron spectra from the experimental BSS data. This paper presents a parametric model specially developed for the unfolding of the experimental data measured with BSS around high-energy electron accelerators. The work consists of the following stages: (1) Generation with the FLUKA code, of a set of neutron spectra representing the radiation environment around accelerators with different electron energies; (2) formulation of a parametric model able to describe these spectra, with particular attention to the high-energy component (>10 MeV), which may be responsible for a large part of the dose in workplaces; and (3) implementation of this model in an existing unfolding code.

  15. The drive system of 100 MeV electron linear accelerator

    International Nuclear Information System (INIS)

    Sun Yuzhen; Su Guoping; Wang Xiulong; Tianlu

    1988-06-01

    The principle, structure, measurement results and technical performances of microwave drive system for 100MeV electron linear accelerator are presented. In this system the peak power of 15 kW is produced by the S bank middle power klystron. The output power of the klystron is divided into six subdrive lines that drive six high power klystrons respectively. The results show the system with simple structure and good characteristics completely meets the requirements of 100 MeV Linac

  16. Observations of collective ion acceleration by a relativistic electron beam in a magnetic cusp

    International Nuclear Information System (INIS)

    Roberson, C.W.; Eckhouse, S.; Fisher, A.; Robertson, S.; Rostoker, N.

    1976-01-01

    Ion pulses of 10 13 protons were observed by passing hollow relativistic electron beams through a magnetic cusp using drift-chamber fill pressures from 75 to 600 mTorr of H 2 . Magnetic fields of 0.8 kG suppress the mechanism responsible for acceleration without magnetic field. A different mechanism appears to begin and peak as the cusp threshold is approached. More than 10 11 protons with energies greater than 2 MeV were observed

  17. Elementary and advanced Lie algebraic methods with applications to accelerator design, electron microscopes, and light optics

    International Nuclear Information System (INIS)

    Dragt, A.J.

    1987-01-01

    A review is given of elementary Lie algebraic methods for treating Hamiltonian systems. This review is followed by a brief exposition of advanced Lie algebraic methods including resonance bases and conjugacy theorems. Finally, applications are made to the design of third-order achromats for use in accelerators, to the design of subangstroem resolution electron microscopes, and to the classification and study of high order aberrations in light optics. (orig.)

  18. Computer control of the beam transport system of the Chalk River electron test accelerator

    International Nuclear Information System (INIS)

    McMichael, G.E.; Kidner, S.H.; Fraser, J.S.

    1977-05-01

    The beam transport system of the Chalk River Electron Test Accelerator comprises steering coils and solenoidal focusing magnets driven by voltage-programmed, current-regulated power supplies. This report describes the beam transport and beam diagnostics systems presently in use. The computer controls all beam transport magnets from a single, allocatable control knob. The system is currently being expanded to two knobs and two readouts. (author)

  19. 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)

  20. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    OpenAIRE

    Yi, Longqing; Pukhov, Alexander; Shen, Baifei

    2016-01-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO$_{2}$ laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energ...

  1. 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

  2. A “slingshot” laser-driven acceleration mechanism of plasma electrons

    Energy Technology Data Exchange (ETDEWEB)

    Fiore, Gaetano, E-mail: gaetano.fiore@na.infn.it [Dip. di Matematica e Applicazioni, Università “Federico II”, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy); INFN, Sezione di Napoli, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy); De Nicola, Sergio [SPIN-CNR, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy); INFN, Sezione di Napoli, Complesso Universitario M. S. Angelo, Via Cintia, 80126 Napoli (Italy)

    2016-09-01

    We briefly report on the recently proposed Fiore et al. [1] and Fiore and De Nicola [2] electron acceleration mechanism named “slingshot effect”: under suitable conditions the impact of an ultra-short and ultra-intense laser pulse against the surface of a low-density plasma is expected to cause the expulsion of a bunch of superficial electrons with high energy in the direction opposite to that of the pulse propagation; this is due to the interplay of the huge ponderomotive force, huge longitudinal field arising from charge separation, and the finite size of the laser spot.

  3. 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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  5. Probing plasma wakefields using electron bunches generated from a laser wakefield accelerator

    Science.gov (United States)

    Zhang, C. J.; Wan, Y.; Guo, B.; Hua, J. F.; Pai, C.-H.; Li, F.; Zhang, J.; Ma, Y.; Wu, Y. P.; Xu, X. L.; Mori, W. B.; Chu, H.-H.; Wang, J.; Lu, W.; Joshi, C.

    2018-04-01

    We show experimental results of probing the electric field structure of plasma wakes by using femtosecond relativistic electron bunches generated from a laser wakefield accelerator. Snapshots of laser-driven linear wakes in plasmas with different densities and density gradients are captured. The spatiotemporal evolution of the wake in a plasma density up-ramp is recorded. Two parallel wakes driven by a laser with a main spot and sidelobes are identified in the experiment and reproduced in simulations. The capability of this new method for capturing the electron- and positron-driven wakes is also shown via 3D particle-in-cell simulations.

  6. Electron beam potential measurements on an inductive-store, opening-switch accelerator

    International Nuclear Information System (INIS)

    Riordan, J.C.; Goyer, J.R.; Kortbawi, D.; Meachum, J.S.; Mendenhall, R.S.; Roth, I.S.

    1993-01-01

    Direct measurement of the accelerating potential in a relativistic electron beam accelerator is difficult, particularly when the diode is downstream from a plasma opening switch. An indirect potential measurement can be obtained from the high energy tail of the bremsstrahlung spectrum generated as the electron beam strikes the anode. The authors' time-resolved spectrometer contains 7 silicon pin diode detectors filtered with 2 to 15 mm of lead to span an electron energy range of 0.5 to 2 MeV. A Monte-Carlo transport code was used to provide calibration curves, and the resulting potential measurements have been confirmed in experiments on the PITHON accelerator. The spectrometer has recently been deployed on PM1, an inductive-store, opening-switch testbed. The diode voltage measurements from the spectrometer are in good agreement with the diode voltage measured upstream and corrected using transmission line relations. The x-ray signal and spectral voltage rise 10 ns later than the corrected electrical voltage, however, indicating plasma motion between the opening switch and the diode

  7. Simulated Prompt Acceleration of Multi-MeV Electrons by the 17 March 2015 Interplanetary Shock

    Science.gov (United States)

    Hudson, Mary; Jaynes, Allison; Kress, Brian; Li, Zhao; Patel, Maulik; Shen, Xiao-Chen; Thaller, Scott; Wiltberger, Michael; Wygant, John

    2017-10-01

    Prompt enhancement of relativistic electron flux at L = 3-5 has been reported from Van Allen Probes Relativistic Electron Proton Telescope (REPT) measurements associated with the 17 March 2015 interplanetary shock compression of the dayside magnetosphere. Acceleration by ˜1 MeV is inferred on less than a drift timescale as seen in prior shock compression events, which launch a magnetosonic azimuthal electric field impulse tailward. This impulse propagates from the dayside around the flanks accelerating electrons in drift resonance at the dusk flank. Such longitudinally localized acceleration events produce a drift echo signature which was seen at >1 MeV energy on both Van Allen Probe spacecraft, with sustained observations by Probe B outbound at L = 5 at 2100 MLT at the time of impulse arrival, measured by the Electric Fields and Waves instrument. MHD test particle simulations are presented which reproduce drift echo features observed in the REPT measurements at Probe B, including the energy and pitch angle dependence of drift echoes observed. While the flux enhancement was short lived for this event due to subsequent inward motion of the magnetopause, stronger events with larger electric field impulses, as observed in March 1991 and the Halloween 2003 storm, produce enhancements which can be quantified by the inward radial transport and energization determined by the induction electric field resulting from dayside compression.

  8. Microbiological decontamination of Spirulina Platensis and green coffee using accelerated electron beams

    International Nuclear Information System (INIS)

    Nemtanu, Monica R.; Brasoveanu, Mirela; Minea, R.; Mitru, Ecaterina; Grecu, Maria Nicoleta; Albulescu, Mihaela

    2006-01-01

    Biological raw materials can be contaminated with microorganisms and to make them suitable for commercialization, the quality relative to microbial content is necessary to be achieved. Irradiation is a decontamination method for numerous foodstuffs, being a feasible, very effective and environment friendly procedure. The aim of the paper is to evaluate the possibility to apply the electron beam treatment on Spirulina Platensis and green coffee for biological decontamination. The cyanobacterium Spirulina and green coffee have been irradiated with electron beams up to 40 kGy. To determine the microbial load, antioxidant activity, and rheological behaviour the techniques of electron paramagnetic resonance (EPR) and absorption spectroscopy have been applied. The results showed that accelerated electron beams could be efficient to decontaminate Spirulina as well as green coffee without significant changes in their properties. (authors)

  9. Luminescent tracks of high-energy photoemitted electrons accelerated by plasmonic fields

    Directory of Open Access Journals (Sweden)

    Di Vece Marcel

    2015-12-01

    Full Text Available The emission of an electron from a metal nanostructure under illumination and its subsequent acceleration in a plasmonic field forms a platform to extend these phenomena to deposited nanoparticles, which can be studied by state-of-the-art confocal microscopy combined with femtosecond optical excitation. The emitted and accelerated electrons leave defect tracks in the immersion oil, which can be revealed by thermoluminescence. These photographic tracks are read out with the confocal microscope and have a maximum length of about 80 μm, which corresponds to a kinetic energy of about 100 keV. This energy is consistent with the energy provided by the intense laser pulse combined with plasmonic local field enhancement. The results are discussed within the context of the rescattering model by which electrons acquire more energy. The visualization of electron tracks originating from plasmonic field enhancement around a gold nanoparticle opens a new way to study with confocal microscopy both the plasmonic properties of metal nano objects as well as high energy electron interaction with matter.

  10. THE EFFECT OF LARGE-SCALE MAGNETIC TURBULENCE ON THE ACCELERATION OF ELECTRONS BY PERPENDICULAR COLLISIONLESS SHOCKS

    International Nuclear Information System (INIS)

    Guo Fan; Giacalone, Joe

    2010-01-01

    We study the physics of electron acceleration at collisionless shocks that move through a plasma containing large-scale magnetic fluctuations. We numerically integrate the trajectories of a large number of electrons, which are treated as test particles moving in the time-dependent electric and magnetic fields determined from two-dimensional hybrid simulations (kinetic ions and fluid electron). The large-scale magnetic fluctuations effect the electrons in a number of ways and lead to efficient and rapid energization at the shock front. Since the electrons mainly follow along magnetic lines of force, the large-scale braiding of field lines in space allows the fast-moving electrons to cross the shock front several times, leading to efficient acceleration. Ripples in the shock front occurring at various scales will also contribute to the acceleration by mirroring the electrons. Our calculation shows that this process favors electron acceleration at perpendicular shocks. The current study is also helpful in understanding the injection problem for electron acceleration by collisionless shocks. It is also shown that the spatial distribution of energetic electrons is similar to in situ observations. The process may be important to our understanding of energetic electrons in planetary bow shocks and interplanetary shocks, and explaining herringbone structures seen in some type II solar radio bursts.

  11. Ultra-High-Contrast Laser Acceleration of Relativistic Electrons in Solid Targets

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, Drew Pitney [Univ. of California, San Diego, CA (United States)

    2013-01-01

    The cone-guided fast ignition approach to Inertial Con nement Fusion requires laser-accelerated relativistic electrons to deposit kilojoules of energy within an imploded fuel core to initiate fusion burn. One obstacle to coupling electron energy into the core is the ablation of material, known as preplasma, by laser energy proceeding nanoseconds prior to the main pulse. This causes the laser-absorption surface to be pushed back hundreds of microns from the initial target surface; thus increasing the distance that electrons must travel to reach the imploded core. Previous experiments have shown an order of magnitude decrease in coupling into surrogate targets when intentionally increasing the amount of preplasma. Additionally, for electrons to deposit energy within the core, they should have kinetic energies on the order of a few MeV, as less energetic electrons will be stopped prior to the core and more energetic electrons will pass through the core without depositing much energy. Thus a quantitative understanding of the electron energy spectrum and how it responds to varied laser parameters is paramount for fast ignition. For the rst time, this dissertation quantitatively investigates the acceleration of electrons using an ultra-high-contrast laser. Ultra-high-contrast lasers reduce the laser energy that reaches the target prior to the main pulse; drastically reducing the amount of preplasma. Experiments were performed in a cone-wire geometry relevant to fast ignition. These experiments irradiated the inner-tip of a Au cone with the laser and observed electrons that passed through a Cu wire attached to the outer-tip of the cone. The total emission of K x-rays is used as a diagnostic to infer the electron energy coupled into the wire. Imaging the x-ray emission allowed an e ective path-length of electrons within the wire to be determined, which constrained the electron energy spectrum. Experiments were carried out on the ultra-high-contrast Trident laser at Los

  12. Final report to US Department of Energy: Cyclotron autoresonance accelerator for electron beam dry scrubbing of flue gases

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, J.L.

    2001-05-25

    Several designs have been built and operated of microwave cyclotron autoresonance accelerators (CARA's) with electron beam parameters suitable for remediation of pollutants in flue gas emissions from coal-burning power plants. CARA designs have also been developed with a TW-level 10.6 micron laser driver for electron acceleration from 50 to 100 MeV, and with UHF drivers for proton acceleration to over 500 MeV. Dose requirements for reducing SO2, NOx, and particulates in flue gas emissions to acceptable levels have been surveyed, and used to optimize the design of an electron beam source to deliver this dose.

  13. Electron beam agrobionanotechnologies for agriculture and food industry enabled by electron accelerators

    Science.gov (United States)

    Pavlov, Y. S.; Revina, A. A.; Souvorova, O. V.; Voropaeva, N. L.; Chekmar, D. V.; Abkhalimov, E. V.; Zavyalov, M. A.; Filippovich, V. P.

    2017-12-01

    Electron beam (EB) radiation technologies have been employed to increase efficiency of biologically active nanochips developed for agricultural plants seed pre-treatment with purpose of enhancing crop yield and productivity. Iron-containing nanoparticles (NPs), synthesized in reverse micelles following known radiation-chemical technique, have served as a multifunctional biologically active and phytosanitary substance of the chips. Porous chip carriers activation has been performed by EB ionization (doze 20kGy) of the active carbons (AC) prepared from agricultural waste and by-products: Jerusalem artichoke (Helianthus tuberosus) straw, rape (Brassica napus L. ssp. oleifera Metzg) straw, camelina (Camelina sativa (L.) Crantz) straw, wheat (Triticum aestivum) straw. Three methods, UV-VIS spectrophotometry, Electron Paramagnetic Resonance (EPR) spectroscopy, cyclic voltammetry (CV) have been used for process control and characterization of radiation-activated and NPs-modified ACs. The results show a notable effect of ACs activation by electron beam radiation, evidenced by FeNPs-adsorption capacity increase. Studies of the impact of Fe NPs-containing nanochip technology on enhancement of seeds germination rate and seedlings vigour suggest that reported electron beam radiation treatment techniques of the ACs from selected agricultural residues may be advantageous for industrial application.

  14. Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection

    Czech Academy of Sciences Publication Activity Database

    Chen, L. J.; Bessho, N.; Lefebvre, B.; Vaith, H.; Asnes, A.; Santolík, Ondřej; Fazakerley, A.; Puhl-Quinn, P.; Bhattacharjee, A.; Khotyaintsev, Y.; Daly, P.; Torbert, R.

    2009-01-01

    Roč. 16, - (2009), 056501/1-056501/12 ISSN 1070-664X Institutional research plan: CEZ:AV0Z30420517 Keywords : magnetotail reconnection * electron current sheet * multispacecraft observations Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.475, year: 2009

  15. Brilliant GeV electron beam with narrow energy spread generated by a laser plasma accelerator

    Directory of Open Access Journals (Sweden)

    Ronghao Hu

    2016-09-01

    Full Text Available The production of GeV electron beam with narrow energy spread and high brightness is investigated using particle-in-cell simulations. A controlled electron injection scheme and a method for phase-space manipulation in a laser plasma accelerator are found to be essential. The injection is triggered by the evolution of two copropagating laser pulses near a sharp vacuum-plasma transition. The collection volume is well confined and the injected bunch is isolated in phase space. By tuning the parameters of the laser pulses, the parameters of the injected electron bunch, such as the bunch length, energy spread, emittance and charge, can be adjusted. Manipulating the phase-space rotation with the rephasing technique, the injected electron bunch can be accelerated to GeV level while keeping relative energy spread below 0.5% and transverse emittance below 1.0  μm. The results present a very promising way to drive coherent x-ray sources.

  16. Neutron research and facility development at the Oak Ridge Electron Linear Accelerator 1970 to 1995

    Energy Technology Data Exchange (ETDEWEB)

    Peelle, R.W.; Harvey, J.A.; Maienschein, F.C.; Weston, L.W.; Olsen, D.K.; Larson, D.C.; Macklin, R.L.

    1982-07-01

    This report reviews the accomplishments of the first decade of operation of the Oak Ridge Electron Linear Accelerator (ORELA) and discusses the plans for the facility in the coming decade. Motivations for scientific and applied research during the next decade are included. In addition, ORELA is compared with competing facilities, and prospects for ORELA's improvement and even replacement are reported. Development efforts for the next few years are outlined that are consistent with the anticipated research goals. Recommendations for hardware development include improving the electron injection system to give much larger short-pulse currents on a reliable basis, constructing an Electron Beam Injector Laboratory to help make this improvement possible, continuing a study of possibly replacing the electron accelerator with a proton machine, and replacing or upgrading the facility's data-acquistion and immediate-analysis computer systems. Increased operating time and more involvement of nuclear theorists are recommended, and an effective staff size for optimum use of this unique facility is discussed. A bibliography of all ORELA-related publications is included.

  17. Design of an electron-accelerator-driven compact neutron source for non-destructive assay

    Science.gov (United States)

    Murata, A.; Ikeda, S.; Hayashizaki, N.

    2017-09-01

    The threat of nuclear and radiological terrorism remains one of the greatest challenges to international security, and the threat is constantly evolving. In order to prevent nuclear terrorism, it is important to avoid unlawful import of nuclear materials, such as uranium and plutonium. Development of technologies for non-destructive measurement, detection and recognition of nuclear materials is essential for control at national borders. At Tokyo Institute of Technology, a compact neutron source system driven by an electron-accelerator has been designed for non-destructive assay (NDA). This system is composed of a combination of an S-band (2.856 GHz) RF-gun, a tungsten target to produce photons by bremsstrahlung, a beryllium target, which is suitable for use in generating neutrons because of the low threshold energy of photonuclear reactions, and a moderator to thermalize the fast neutrons. The advantage of this system can accelerate a short pulse beam with a pulse width less than 1 μs which is difficult to produce by neutron generators. The amounts of photons and neutron produced by electron beams were simulated using the Monte Carlo simulation code PHITS 2.82. When the RF-gun is operated with an average electron beam current of 0.1 mA, it is expected that the neutron intensities are 1.19 × 109 n/s and 9.94 × 109 n/s for incident electron beam energies of 5 MeV and 10 MeV, respectively.

  18. Direct acceleration of electrons by a CO2 laser in a curved plasma waveguide

    Science.gov (United States)

    Yi, Longqing; Pukhov, Alexander; Shen, Baifei

    2016-06-01

    Laser plasma interaction with micro-engineered targets at relativistic intensities has been greatly promoted by recent progress in the high contrast lasers and the manufacture of advanced micro- and nano-structures. This opens new possibilities for the physics of laser-matter interaction. Here we propose a novel approach that leverages the advantages of high-pressure CO2 laser, laser-waveguide interaction, as well as micro-engineered plasma structure to accelerate electrons to peak energy greater than 1 GeV with narrow slice energy spread (~1%) and high overall efficiency. The acceleration gradient is 26 GV/m for a 1.3 TW CO2 laser system. The micro-bunching of a long electron beam leads to the generation of a chain of ultrashort electron bunches with the duration roughly equal to half-laser-cycle. These results open a way for developing a compact and economic electron source for diverse applications.

  19. Temporal characteristics of monoenergetic electron beams generated by the laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    T. Ohkubo

    2007-03-01

    Full Text Available Pulse length of quasimonoenergetic electrons accelerated by the wakefield generated by 12 TW, 40 fs laser pulses in a gas jet is determined via spectral measurements using a bolometer to detect coherent transition radiation. A quasimonoenergetic electron beam with its mean energy E=21  MeV, dispersion ΔE=4  MeV, total charge q∼30  pC, and the geometrical emittance 0.07π  mm mrad is generated with high reproducibility. The averaged duration of only the quasimonoenergetic electron bunches peaked around 20 MeV is 130±30  fs (FWHM, while it is 250±70  fs (FWHM for electron bunches with quasimonoenergetic distributions peaked around 4 MeV, at a distance of 180 mm far from the gas jet because of relatively large electron energy spread. Pulse elongation of the electron bunch with the quasimonoenergetic distribution after 180 mm path is 60–220  fs (FWHM. Therefore, the initial duration of the electron bunch at the gas-jet rear is expected to be less than 100  fs (FWHM.

  20. Acceleration and Propagation of Anomalous Cosmic Rays and Near-Relativistic Electrons in the Heliosheath

    Science.gov (United States)

    Roelof, E. C.

    2017-12-01

    Voyager 1/2 LECP observations at the termination shock (TS) crossings established that energetic ions (40keV-1MeV) appeared to be locally accelerated "termination shock particles", and since then have exhibited remarkably steady and similar intensities at both spacecraft throughout the heliosheath (HS). On the other hand, the anomalous cosmic rays (ACRs, 4-80 MeV total energy H, He, and O ions) increased more or less steadily across the shock and then gradually peaked years later. All the time in the HS, the ACRs at each spacecraft exhibited a striking "common spectrum", i.e., closely similar intensity histories when ordered by total energy. Near-relativistic electrons (30 keV-1 MeV) exhibited seemingly mutually inconsistent behavior while the two Voyagers transited the shock and HS, with the VGR2 electrons peaking at the shock, but later disappearing for a year (in 2010) and then slowly recovering, as opposed to the less variable VGR1 electrons whose remarkably smooth time history (2008-2012) was very similar to the VGR1 ACRs. Consequently, shock acceleration seems to be operating locally at the TS along with another spatially distributed acceleration/transport mechanism within the HS. The "reservoir" equation (Roelof, AIP Conf. Proc., 1500, 174-179 and 180-184, 2012) offers quantitative explanations for many of these apparently disparate observations. Meso-scale gradients and curvatures in the magnetic field produce transverse transport of energetic particles and (in direct consequence) "transverse compressive" acceleration that relates the fractional rate of momentum d(lnp)/dt=-(1/3)div(Vperp) to the divergence of the component of the plasma velocity transverse to the magnetic field. However, this acceleration rate must compete with the extinction rate of singly-charged ions due to charge exchange with the cold interstellar neutral H-atoms that permeate the HS. The agreement of the Voyager 1/2 LECP observations with the acceleration/extinction processes has

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

    Directory of Open Access Journals (Sweden)

    J. B. Rosenzweig

    2004-06-01

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

  2. Application of magnetically insulated transmission lines for high current, high voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Shope, S.L.; Mazarakis, M.G.; Frost, C.A.; Poukey, J.W.; Turman, B.N.

    1993-01-01

    Self Magnetically Insulated Transmission Lines (MITL) adders have been used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently the authors used a MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (r b < 2 cm), 11 to 15 MeV, 50 to 100-kA beams with a small transverse velocity v perpendicular/c = β perpendicular ≤ 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. The authors' success with the MITL technology led them to investigate the application to higher energy accelerator designs. They have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30-50-ns FWHM output pulse

  3. Application of Magnetically Insulated Transmission Lines for high current, high voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Shope, S.L.; Mazarakis, M.G.; Frost, C.A.; Poukey, J.W.; Turman, B.N.

    1991-01-01

    Self Magnetically Insulated Transmission Lines (MITL) adders have been used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently we used at MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (r ρ < 2 cm), 11 to 15 MeV, 50 to 100-kA beams with a small transverse velocity v perpendicular/c = β perpendicular ≤ 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. Our success with the MITL technology led us to investigate the application to higher energy accelerator designs. We have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30--50 ns FWHM output pulse. 10 refs

  4. Status of control systems for industrial electron accelerators at EBC, Kharghar

    International Nuclear Information System (INIS)

    Jain, Arvind; Kumar, Mukesh; Kaurav, P.S.; Sharma, Vijay; Chawla, A.S.; Sethi, R.C.

    2005-01-01

    The Bhabha Atomic Research Centre (BARC) is setting up two industrial electron accelerators at the Electron Beam Center (EBC) Kharghar. These are a 10 MeV, 10 KW beam power RF linac and a 30 KW, DC, Dynamitron type of machine. The present status of the control systems of these accelerators are presented. Some novel features in the design of the control system include (a) the software and hardware of the control system has been designed such that the same package can be used for the two widely different machines. Thus the control system developed can be used for any new accelerator also by reformatting the built in data base (b) an attempt is being made towards push button operation to minimize the need for machine operators. This is achieved by a sequential start-up and shut down procedure with appropriate time lags built into the software. The PC based centralized control system has been tested and now gives automated operation of the 22 sub-systems of the linac and operating experience of the system for the last one year has been achieved. Similarly, the control system of the 3 MeV DC machine having about 20 subsystems are in the final stage of commissioning and testing. (author)

  5. The effect of voltage droop on the output of an electrostatic accelerator free electron laser

    CERN Document Server

    Wright, C C; Lucas, J; Stuart, R A

    2000-01-01

    Electrostatic accelerator FEL oscillators when operated with energy recovery offer the prospect of long pulse, single-mode operation with very narrow linewidth at high-power levels. However, special care with wiggler construction, electron beam steering, and collector design is necessary to reduce the fraction of the electron beam lost before depressed collection to a sufficiently small value to stop the output hopping from one longitudinal mode of the cavity to another due to the droop of the terminal accelerating voltage. We are investigating what minimum recovery fraction is required both experimentally and theoretically. We have constructed a pulsed microwave FEM oscillator having an accelerating voltage of 65 kV supplied by a source, which is a capacitor, charged by a low-current, high-voltage supply. By changing the capacitor value, it is easily possible to achieve a range of voltage droop rates. Furthermore, because the gain bandwidth of the FEM is small, only 1 or 2 longitudinal modes are capable of b...

  6. Coherent-phase or random-phase acceleration of electron beams in solar flares

    Science.gov (United States)

    Aschwanden, Markus J.; Benz, Arnold O.; Montello, Maria L.

    1994-01-01

    Time structures of electron beam signatures at radio wavelengths are investigated to probe correlated versus random behavior in solar flares. In particular we address the issue whether acceleration and injection of electron beams is coherently modulated by a single source, or whether the injection is driven by a stochastic (possibly spatially fragmented) process. We analyze a total of approximately = 6000 type III bursts observed by Ikarus (Zurich) in the frequency range of 100-500 MHz, during 359 solar flares with simultaneous greater than or = 25 keV hard X-ray emission, in the years 1890-1983. In 155 flares we find a total of 260 continuous type III groups, with an average number of 13 +/- 9 bursts per group, a mean duration of D = 12 +/- 14 s, a mean period of P = 2.0 +/- 1.2 s, with the highest burst rate at a frequency of nu = 310 +/- 120 MHz. Pulse periods have been measured between 0.5 and 10 s, and can be described by an exponential distribution, i.e., N(P) varies as e (exp -P/1.0s). The period shows a frequency dependence of P(nu)=46(exp-0.6)(sub MHz)s for different flares, but is invariant during a particular flare. We measure the mean period P and its standard deviation sigma (sub p) in each type III group, and quantify the degree of periodicity (or phase-coherence) by the dimensionless parameter sigma (sub p)P. The representative sample of 260 type III burst groups shows a mean periodicity of sigma (sub p/P) = 0.37 +/- 0.12, while Monte Carlo simulations of an equivalent set of truly random time series show a distinctly different value of sigma (sub p)P = 0.93 +/- 0.26. This result indicates that the injection of electron beams is coherently modulated by a particle acceleration source which is either compact or has a global organization on a timescale of seconds, in contrast to an incoherent acceleration source, which is stochastic either in time or space. We discuss the constraints on the size of the acceleration region resulting from electron beam

  7. Ant colony method to control variance reduction techniques in the Monte Carlo simulation of clinical electron linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Pareja, S. [Servicio de Radiofisica Hospitalaria, Hospital Regional Universitario ' Carlos Haya' , Avda. Carlos Haya, s/n, E-29010 Malaga (Spain)], E-mail: garciapareja@gmail.com; Vilches, M. [Servicio de Fisica y Proteccion Radiologica, Hospital Regional Universitario ' Virgen de las Nieves' , Avda. de las Fuerzas Armadas, 2, E-18014 Granada (Spain); Lallena, A.M. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain)

    2007-09-21

    The ant colony method is used to control the application of variance reduction techniques to the simulation of clinical electron linear accelerators of use in cancer therapy. In particular, splitting and Russian roulette, two standard variance reduction methods, are considered. The approach can be applied to any accelerator in a straightforward way and permits, in addition, to investigate the 'hot' regions of the accelerator, an information which is basic to develop a source model for this therapy tool.

  8. Ant colony method to control variance reduction techniques in the Monte Carlo simulation of clinical electron linear accelerators

    International Nuclear Information System (INIS)

    Garcia-Pareja, S.; Vilches, M.; Lallena, A.M.

    2007-01-01

    The ant colony method is used to control the application of variance reduction techniques to the simulation of clinical electron linear accelerators of use in cancer therapy. In particular, splitting and Russian roulette, two standard variance reduction methods, are considered. The approach can be applied to any accelerator in a straightforward way and permits, in addition, to investigate the 'hot' regions of the accelerator, an information which is basic to develop a source model for this therapy tool

  9. Pulse radiolysis with (sub) nanosecond time resolution using a 3 MV electron accelerator

    International Nuclear Information System (INIS)

    Luthjens, L.H.

    1986-01-01

    In this thesis the development of equipment for pulse radiolysis is described and the application of the technique to time-resolved measurements of the fluorescence emission of excited states formed after irradiation of some alkanes is dealt with. A review is given of the development of the pulsed 3MV Van de Graaf electron accelerator for the generation of subnanosecond electron beam pulses and of the development of the equipment for optical detection as accomplished by the author. The initial stage of a further development for shorter pulses and higher time resolution is briefly discussed. A collection of papers on the development of apparatus and a collection of papers dealing with the results obtained from measurements of the fluorescence of excited states, formed by the recombination of electrons and ions in irradiated alkanes such as cyclohexane and the decalines, are included. (Auth.)

  10. An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

    Energy Technology Data Exchange (ETDEWEB)

    C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg

    2011-09-01

    We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ('afterburner'). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

  11. Terahertz radiation source using a high-power industrial electron linear accelerator

    Science.gov (United States)

    Kalkal, Yashvir; Kumar, Vinit

    2017-04-01

    High-power (˜ 100 kW) industrial electron linear accelerators (linacs) are used for irradiations, e.g., for pasteurization of food products, disinfection of medical waste, etc. We propose that high-power electron beam from such an industrial linac can first pass through an undulator to generate useful terahertz (THz) radiation, and the spent electron beam coming out of the undulator can still be used for the intended industrial applications. This will enhance the utilization of a high-power industrial linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of μW can be produced, which may be useful for many scientific applications such as multispectral imaging of biological samples, chemical samples etc.

  12. CAS CERN Accelerator School. Synchrotron radiation and free electron lasers. Proceedings

    International Nuclear Information System (INIS)

    Turner, S.

    1998-01-01

    These proceedings present the lectures given at the tenth specialised course organised by the CERN Accelerator School (CAS), the topic this time being 'Synchrotron Radiation and Free-electron Lasers'. A similar course was already given at Chester, UK in 1989 and whose proceedings were published as CERN 90-03. However, recent progress in this field has been so rapid that it became urgent to present a revised version of the course. Starting with a review of the characteristics of synchrotron radiation there follows introductory lectures on electron dynamics in storage rings, beam insertion devices, and beam current and radiation brightness limits. These themes are then developed with more detailed lectures on lattices and emittance, wigglers and undulators, current limitations, beam lifetime and quality, diagnostics and beam stability. Finally lectures are presented on linac and storage ring free-electron lasers. (orig.)

  13. Evidence for acceleration of outer zone electrons to relativistic energies by whistler mode chorus

    Directory of Open Access Journals (Sweden)

    N. P. Meredith

    2002-07-01

    Full Text Available We use plasma wave and electron data from the Combined Release and Radiation Effects Satellite (CRRES to investigate the viability of a local stochastic electron acceleration mechanism to relativistic energies driven by gyroresonant interactions with whistler mode chorus. In particular, we examine the temporal evolution of the spectral response of the electrons and the waves during the 9 October 1990 geomagnetic storm. The observed hardening of the electron energy spectra over about 3 days in the recovery phase is coincident with prolonged substorm activity, as monitored by the AE index and enhanced levels of whistler mode chorus waves. The observed spectral hardening is observed to take place over a range of energies appropriate to the resonant energies associated with Doppler-shifted cyclotron resonance, as supported by the construction of realistic resonance curves and resonant diffusion surfaces. Furthermore, we show that the observed spectral hardening is not consistent with energy-independent radial diffusion models. These results provide strong circumstantial evidence for a local stochastic acceleration mechanism, involving the energisation of a seed population of electrons with energies of the order of a few hundred keV to relativistic energies, driven by wave-particle interactions involving whistler mode chorus. The results suggest that this mechanism contributes to the reformation of the relativistic outer zone population during geomagnetic storms, and is most effective when the recovery phase is characterised by prolonged substorm activity. An additional significant result of this paper is that we demonstrate that the lower energy part of the storm-time electron distribution is in steady-state balance, in accordance with the Kennel and Petschek (1966 theory of limited stably-trapped particle fluxes.Key words. Magnetospheric physics (storms and substorms, energetic particles, trapped – Space plasma physics (wave-particle interactions

  14. Electron-beam dynamics for an advanced flash-radiography accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Carl August Jr. [Los Alamos National Laboratory

    2015-06-22

    Beam dynamics issues were assessed for a new linear induction electron accelerator. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Beam physics issues were examined through theoretical analysis and computer simulations, including particle-in cell (PIC) codes. Beam instabilities investigated included beam breakup (BBU), image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. Beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos will result if the same engineering standards and construction details are upheld.

  15. Extremely intense laser-based electron acceleration in a plasma channel

    Science.gov (United States)

    Vranic, Marija; Fonseca, Ricardo A.; Silva, Luis O.

    2018-03-01

    Laser pulses of extreme intensities (I> {10}22 {{W}} {{cm}}-2) are about to become available in the laboratory. The prepulse of such a laser can induce a plasma expansion that generates a low-density channel in near-critical gas jets. We present a study of channel formation and subsequent direct laser acceleration of electrons within the pre-formed channel. Radiation reaction affects the acceleration in several ways. It first interferes with the motion of the return current on the channel walls. In addition, it reduces the radial expelling efficiency of the transverse ponderomotive force, leading to the radiative trapping of particles near the channel axis. These particles then interact with the peak laser intensity and can attain multi-GeV energies.

  16. Parametric emittance measurements of electron beams produced by a laser plasma accelerator

    Science.gov (United States)

    Barber, S. K.; van Tilborg, J.; Schroeder, C. B.; Lehe, R.; Tsai, H.-E.; Swanson, K. K.; Steinke, S.; Nakamura, K.; Geddes, C. G. R.; Benedetti, C.; Esarey, E.; Leemans, W. P.

    2018-05-01

    Laser plasma accelerators (LPA) offer an exciting possibility to deliver high energy, high brightness electrons beams in drastically smaller distance scales than is typical for conventional accelerators. As such, LPAs draw considerable attention as potential drivers for next generation light sources and for a compact linear collider. In order to asses the viability of an LPA source for a particular application, the brightness of the source should be properly characterized. In this paper, we present charge dependent transverse emittance measurements of LPA sources using both ionization injection and shock induced density down ramp injection, with the latter delivering smaller transverse emittances by a factor of two when controlling for charge density. The single shot emittance method is described in detail with a discussion on limitations related to second order transport effects. The direct role of space charge is explored through a series of simulations and found to be consistent with experimental observations.

  17. Concepts and techniques: Active electronics and computers in safety-critical accelerator operation

    International Nuclear Information System (INIS)

    Frankel, R.S.

    1995-01-01

    The Relativistic Heavy Ion Collider (RHIC) under construction at Brookhaven National Laboratory, requires an extensive Access Control System to protect personnel from Radiation, Oxygen Deficiency and Electrical hazards. In addition, the complicated nature of operation of the Collider as part of a complex of other Accelerators necessitates the use of active electronic measurement circuitry to ensure compliance with established Operational Safety Limits. Solutions were devised which permit the use of modern computer and interconnections technology for Safety-Critical applications, while preserving and enhancing, tried and proven protection methods. In addition a set of Guidelines, regarding required performance for Accelerator Safety Systems and a Handbook of design criteria and rules were developed to assist future system designers and to provide a framework for internal review and regulation

  18. Concepts and techniques: Active electronics and computers in safety-critical accelerator operation

    Energy Technology Data Exchange (ETDEWEB)

    Frankel, R.S.

    1995-12-31

    The Relativistic Heavy Ion Collider (RHIC) under construction at Brookhaven National Laboratory, requires an extensive Access Control System to protect personnel from Radiation, Oxygen Deficiency and Electrical hazards. In addition, the complicated nature of operation of the Collider as part of a complex of other Accelerators necessitates the use of active electronic measurement circuitry to ensure compliance with established Operational Safety Limits. Solutions were devised which permit the use of modern computer and interconnections technology for Safety-Critical applications, while preserving and enhancing, tried and proven protection methods. In addition a set of Guidelines, regarding required performance for Accelerator Safety Systems and a Handbook of design criteria and rules were developed to assist future system designers and to provide a framework for internal review and regulation.

  19. A study of an electron gun controlled with a meshless grid for a linear accelerator

    International Nuclear Information System (INIS)

    Homma, Akira; Nakata, Katsuhide; Sawamura, Teruko; Narita, Masakuni

    1996-01-01

    An electron gun for a linear accelerator with a control grid of meshless electrode (meshless grid) is expected to overcome some disadvantages of beam quality using an ordinary mesh grid. A gun of this type was designed and its characteristics were numerically analyzed. The simulation program code Egn2 with a boundary setting routine POLYGON was used. The result indicated that the grid can control the beam launched from the cathode to the anode electrode. It also indicated the Ip-Vp and Ip-Vp characteristics which are different from an ordinary triode gun with a mesh-grid. The mutual conductance gm of 0.4[mS], the maximum average current of 1.6[A] and cut-off voltage -200[V] were obtained under a condition of 200[kV] acceleration voltage. (author)

  20. Evolution of pulse shapes during compressor scans in a CPA system and control of electron acceleration in plasmas

    International Nuclear Information System (INIS)

    Toth, Csaba; Groot, Joeri de; Tilborg, Jeroen van; Geddes, Cameron G.R.; Faure, Jerome; Catravas, Palma; Schroeder, Carl; Shadwick, B.A.; Esarey, Eric; Leemans, Wim

    2002-01-01

    The skewness of the envelope function of 20 - 100 femtosecond Ti:sapphire laser pulses has been controlled by appropriate choice of the higher order special phase coefficients, and used for optimization of a plasma wakefield electron accelerator

  1. Dose properties of x-ray beams produced by laser-wakefield-accelerated electrons

    International Nuclear Information System (INIS)

    Kainz, K K; Hogstrom, K R; Antolak, J A; Almond, P R; Bloch, C D

    2005-01-01

    Given that laser wakefield acceleration (LWFA) has been demonstrated experimentally to accelerate electron beams to energies beyond 25 MeV, it is reasonable to assess the ability of existing LWFA technology to compete with conventional radiofrequency linear accelerators in producing electron and x-ray beams for external-beam radiotherapy. We present calculations of the dose distributions (off-axis dose profiles and central-axis depth dose) and dose rates of x-ray beams that can be produced from electron beams that are generated using state-of-the-art LWFA. Subsets of an LWFA electron energy distribution were propagated through the treatment head elements (presuming an existing design for an x-ray production target and flattening filter) implemented within the EGSnrc Monte Carlo code. Three x-ray energy configurations (6 MV, 10 MV and 18 MV) were studied, and the energy width ΔE of the electron-beam subsets varied from 0.5 MeV to 12.5 MeV. As ΔE increased from 0.5 MeV to 4.5 MeV, we found that the off-axis and central-axis dose profiles for x-rays were minimally affected (to within about 3%), a result slightly different from prior calculations of electron beams broadened by scattering foils. For ΔE of the order of 12 MeV, the effect on the off-axis profile was of the order of 10%, but the central-axis depth dose was affected by less than 2% for depths in excess of about 5 cm beyond d max . Although increasing ΔE beyond 6.5 MeV increased the dose rate at d max by more than 10 times, the absolute dose rates were about 3 orders of magnitude below those observed for LWFA-based electron beams at comparable energies. For a practical LWFA-based x-ray device, the beam current must be increased by about 4-5 orders of magnitude. (note)

  2. Characterization of electron clouds in the Cornell Electron Storage Ring Test Accelerator using TE-wave transmission

    Directory of Open Access Journals (Sweden)

    S. De Santis

    2010-07-01

    Full Text Available A relatively new technique for measuring the electron cloud density in storage rings has been developed and successfully demonstrated [S. De Santis, J. M. Byrd, F. Caspers, A. Krasnykh, T. Kroyer, M. T. F. Pivi, and K. G. Sonnad, Phys. Rev. Lett. 100, 094801 (2008.PRLTAO0031-900710.1103/PhysRevLett.100.094801]. We present the experimental results of a systematic application of this technique at the Cornell Electron Storage Ring Test Accelerator. The technique is based on the phase modulation of the TE mode transmitted in a synchrotron beam pipe caused by the periodic variation of the density of electron plasma. Because of the relatively simple hardware requirements, this method has become increasingly popular and has been since successfully implemented in several machines. While the principles of this technique are straightforward, quantitative derivation of the electron cloud density from the measurement requires consideration of several effects, which we address in detail.

  3. Beam-Induced Multipactoring and Electron-Cloud Effects in Particle Accelerators

    CERN Document Server

    Caspers, Friedhelm; Scandale, Walter; Zimmermann, F

    2009-01-01

    In the beam pipe of high-energy proton or positron accelerators an “electron cloud” can be generated by a variety of processes, e.g. by residual-gas ionization, by photoemission from synchrotron radiation, and, most importantly, by secondary emission via a beam-induced multipactoring process. The electron cloud commonly leads to a degradation of the beam vacuum by several orders of magnitude, to fast beam instabilities, to beam-size increases, and to fast or slow beam losses. At the Large Hadron Collider (LHC), the cloud electrons could also give rise to an additional heat load inside cold superconducting magnets. In addition to the direct heat deposition from incoherently moving electrons, a potential “magnetron effect” has been conjectured, where electrons would radiate coherently when moving in a strong magnetic field under the simultaneous influence of a beam-induced electric “wake” field that may become resonant with the cyclotron frequency. Electron-cloud effects are already being observed w...

  4. Intermediate energy electron cooling for antiproton sources using a Pelletron accelerator

    International Nuclear Information System (INIS)

    Cline, D.B.; Adney, J.; Ferry, J.; Kells, W.; Larson, D.J.; Mills, F.E.; Sundquist, M.

    1983-01-01

    It has been shown at FNAL that the electron cooling of protons is a very efficient method for reaching high luminosity in a proton beam. The emittance of the 120 KeV electron beam used at Fermilab corresponds to a cathode temperature of 0.1 eV. In order to apply cooling techniques to GeV proton beams the electron energies required are in the MeV range. In the experiment reported in this paper the emittance of a 3-MeV Pelletron electron accelerator was measured to determine that its emittance scaled to a value appropriate for electron cooling. The machine tested was jointly owned and operated by the University of California at Santa Barbara and National Electrostatics Corporation for research into free-electron lasers which also require low emittance beams for operation. This paper describes the thermal emittance of the beam to be the area in phase space in which 90% of the beam trajectories lie and goes on to describe the emittance-measurement method both in theory and application

  5. Quasi-phase-matched acceleration of electrons in a corrugated plasma channel

    Directory of Open Access Journals (Sweden)

    S. J. Yoon

    2012-08-01

    Full Text Available A laser pulse propagating in a corrugated plasma channel is composed of spatial harmonics whose phase velocities can be subluminal. The phase velocity of a spatial harmonic can be matched to the speed of a relativistic electron resulting in direct acceleration by the guided laser field in a plasma waveguide and linear energy gain over the interaction length. Here we examine the fully self-consistent interaction of the laser pulse and electron beam using particle-in-cell (PIC simulations. For low electron beam densities, we find that the ponderomotive force of the laser pulse pushes plasma channel electrons towards the propagation axis, which deflects the beam electrons. When the beam density is high, the space charge force of the beam drives the channel electrons off axis, providing collimation of the beam. In addition, we consider a ramped density profile for lowering the threshold energy for trapping in a subluminal spatial harmonic. By using a density ramp, the trapping energy for a normalized vector potential of a_{0}=0.1 is reduced from a relativistic factor γ_{0}=170 to γ_{0}=20.

  6. Accelerated electron paramagnetic resonance imaging using partial Fourier compressed sensing reconstruction.

    Science.gov (United States)

    Chou, Chia-Chu; Chandramouli, Gadisetti V R; Shin, Taehoon; Devasahayam, Nallathamby; McMillan, Alan; Babadi, Behtash; Gullapalli, Rao; Krishna, Murali C; Zhuo, Jiachen

    2017-04-01

    Electron paramagnetic resonance (EPR) imaging has evolved as a promising tool to provide non-invasive assessment of tissue oxygenation levels. Due to the extremely short T 2 relaxation time of electrons, single point imaging (SPI) is used in EPRI, limiting achievable spatial and temporal resolution. This presents a problem when attempting to measure changes in hypoxic state. In order to capture oxygen variation in hypoxic tissues and localize cycling hypoxia regions, an accelerated EPRI imaging method with minimal loss of information is needed. We present an image acceleration technique, partial Fourier compressed sensing (PFCS), that combines compressed sensing (CS) and partial Fourier reconstruction. PFCS augments the original CS equation using conjugate symmetry information for missing measurements. To further improve image quality in order to reconstruct low-resolution EPRI images, a projection onto convex sets (POCS)-based phase map and a spherical-sampling mask are used in the reconstruction process. The PFCS technique was used in phantoms and in vivo SCC7 tumor mice to evaluate image quality and accuracy in estimating O 2 concentration. In both phantom and in vivo experiments, PFCS demonstrated the ability to reconstruct images more accurately with at least a 4-fold acceleration compared to traditional CS. Meanwhile, PFCS is able to better preserve the distinct spatial pattern in a phantom with a spatial resolution of 0.6mm. On phantoms containing Oxo63 solution with different oxygen concentrations, PFCS reconstructed linewidth maps that were discriminative of different O 2 concentrations. Moreover, PFCS reconstruction of partially sampled data provided a better discrimination of hypoxic and oxygenated regions in a leg tumor compared to traditional CS reconstructed images. EPR images with an acceleration factor of four are feasible using PFCS with reasonable assessment of tissue oxygenation. The technique can greatly enhance EPR applications and improve our

  7. Preliminary Safety Analysis Report (PSAR), The NSLS 200 MeV Linear Electron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Blumberg, L.N.; Ackerman, A.I.; Dickinson, T.; Heese, R.N.; Larson, R.A.; Neuls, C.W.; Pjerov, S.; Sheehan, J.F.

    1993-06-15

    The radiological, fire and electrical hazards posed by a 200 MeV electron Linear Accelerator, which the NSLS Department will install and commission within a newly assembled structure, are addressed in this Preliminary Safety Analysis Report. Although it is clear that this accelerator is intended to be the injector for a future experimental facility, we address only the Linac in the present PSAR since neither the final design nor the operating characteristics of the experimental facility are known at the present time. The fire detection and control system to be installed in the building is judged to be completely adequate in terms of the marginal hazard presented - no combustible materials other than the usual cabling associated with such a facility have been identified. Likewise, electrical hazards associated with power supplies for the beam transport magnets and accelerator components such as the accelerator klystrons and electron gun are classified as marginal in terms of potential personnel injury, cost of equipment lost, program downtime and public impact perceptions as defined in the BNL Environmental Safety and Health Manual and the probability of occurrence is deemed to be remote. No unusual features have been identified for the power supplies or electrical distribution system, and normal and customary electrical safety standards as practiced throughout the NSLS complex and the Laboratory are specified in this report. The radiation safety hazards are similarly judged to be marginal in terms of probability of occurrence and potential injury consequences since, for the low intensity operation proposed - a factor of 25 less than the maximum Linac capability specified by the vendor - the average beam power is only 0.4 watts. The shielding specifications given in this report will give adequate protection to both the general public and nonradiation workers in areas adjacent to the building as well as radiation workers within the controlled access building.

  8. Future electron accelerators and free electron lasers: Potentials in clinical medicine

    Science.gov (United States)

    Larsson, Börje; Stepanek, Jiri

    1997-10-01

    Studies of the biological and technical prerequisites for the clinical use of monoenergetic X-rays, and their specific absorption in heavy elements are conducted, with a view towards plans for stereotactic photon activation radiosurgery. The primary aim is the controlled eradication of target structures in the brain for the treatment of functional brain disorders or small brain tumours, with monochromatic synchrotron X-rays. The specific cell-killing action is based on DNA-breakage caused by short-range Auger and Coster-Kronig electrons produced by heavy atoms upon K-shell absorption of their characteristic X-rays. To this end, iodine or heavy metals would have to be deposited, in or close to nuclear DNA in target cells by means of suitable molecular vehicles. Practically useful concepts for clinically useful monoenergetic X-ray facilities and beam-lines are being developed. In this paper attention is focussed on the possible use of laser Compton backscattering for the production of clinically useful monochromatic X-ray beams suitable for irradiation of very small targets in the brain through the intact skull. Particularly relevant, in the present context are prospects for introducing free electron laser technology to improve the calculated parameters of X-ray beams designed for stereotactic photon activation radiosurgery with monochromatic photons in the energy interval 30-100 keV. Constructive initiatives would be welcome!

  9. Distributed grating-assisted coupler for optical all-dielectric electron accelerator

    Directory of Open Access Journals (Sweden)

    Zhiyu Zhang

    2005-07-01

    Full Text Available A Bragg waveguide consisting of multiple dielectric layers with alternating index of refraction becomes an excellent option to form electron accelerating structure powered by high power laser sources. It provides confinement of a synchronous speed-of-light mode with extremely low loss. However, laser field cannot be coupled into the structure collinearly with the electron beam. There are three requirements in designing input coupler for a Bragg electron accelerator: side coupling, selective mode excitation, and high coupling efficiency. We present a side-coupling scheme using a distributed grating-assisted coupler to inject the laser power into the waveguide. Side coupling is achieved by a grating with a period on the order of an optical wavelength. The phase matching condition results in resonance coupling thus providing selective mode excitation capability. The coupling efficiency is limited by profile matching between the outgoing beam and the incoming beam, which has normally a Gaussian profile. We demonstrate a nonuniform distributed grating structure generating an outgoing beam with a Gaussian profile, therefore, increasing the coupling efficiency.

  10. On-site installation and shielding of a mobile electron accelerator for radiation processing

    International Nuclear Information System (INIS)

    Catana, D.; Panaitescu, J.; Axinescu, S.; Manolache, D.; Matei, C.; Corcodel, C.; Ulmeanu, M..; Bestea, V.

    1995-01-01

    The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account. (orig.)

  11. Non-Maxwellian electron distributions by direct laser acceleration in near-critical plasmas

    Science.gov (United States)

    Toncian, T.; Wang, C.; Arefiev, A.; McCary, E.; Meadows, A.; Blakeney, J.; Chester, C.; Roycroft, R.; Fu, H.; Yan, X. Q.; Schreiber, J.; Pomerantz, I.; Quevedo, H.; Dyer, G.; Gaul, E.; Ditmire, T.; Hegelich, B. M.

    2015-11-01

    The irradiation of few nm thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse. The targets will decompress to near and lower than critical electron densities plasmas extending over lengths of few micrometers. The laser-matter interaction of the main pulse with such a highly localized but inhomogeneous the target leads to the generation of a channel and further self focussing of the laser beam. As measured in a experiment conducted with the GHOST laser system at UT Austin, 2D PIC simulations predict Direct Laser Acceleration of non-Maxwellian electron distribution in the laser propagation direction for such targets. The hereby high density electron bunches have potential applications as injector beams for a further wakefield acceleration stage. This work was supported by NNSA cooperative agreement DE-NA0002008, the DARPA's PULSE program (12-63-PULSE-FP014) and the AFOSR (FA9550-14-1-0045).

  12. Non-Maxwellian electron distributions resulting from direct laser acceleration in near-critical plasmas

    Directory of Open Access Journals (Sweden)

    T. Toncian

    2016-01-01

    Full Text Available The irradiation of few-nm-thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse. The targets decompress to near and lower than critical densities with plasmas extending over few micrometers, i.e. multiple wavelengths. The interaction of the main pulse with such a highly localized but inhomogeneous target leads to the generation of a short channel and further self-focusing of the laser beam. Experiments at the Glass Hybrid OPCPA Scaled Test-bed (GHOST laser system at University of Texas, Austin using such targets measured non-Maxwellian, peaked electron distribution with large bunch charge and high electron density in the laser propagation direction. These results are reproduced in 2D PIC simulations using the EPOCH code, identifying direct laser acceleration (DLA [1] as the responsible mechanism. This is the first time that DLA has been observed to produce peaked spectra as opposed to broad, Maxwellian spectra observed in earlier experiments [2]. This high-density electrons have potential applications as injector beams for a further wakefield acceleration stage as well as for pump-probe applications.

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

    Science.gov (United States)

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

    2012-07-01

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

  14. Initial Observations of Micropulse Elongation of Electron Beams in a SCRF Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Thurman-Keup, R. [Fermilab; Edstrom Jr., D. [Fermilab; Ruan, J. [Fermilab; Santucci, J. [Fermilab

    2016-10-09

    Commissioning at the SCRF accelerator at the Fermilab Accelerator Science and Technology (FAST) Facility has included the implementation of a versatile bunch-length monitor located after the 4-dipole chicane bunch compressor for electron beam energies of 20-50 MeV and integrated charges in excess of 10 nC. The team has initially used a Hamamatsu C5680 synchroscan streak camera to assess the effects of space charge on the electron beam bunch lengths. An Al-coated Si screen was used to generate optical transition radiation (OTR) resulting from the beam’s interaction with the screen. The chicane bypass beamline allowed the measurements of the bunch length without the compression stage at the downstream beamline location using OTR and the streak camera. We have observed electron beam bunch lengths from 5 to 16 ps (sigma) for micropulse charges of 60 pC to 800 pC, respectively. We also report a compressed sub-ps micropulse case.

  15. Dose properties of a laser accelerated electron beam and prospects for clinical application

    International Nuclear Information System (INIS)

    Kainz, K.K.; Hogstrom, K.R.; Antolak, J.A.; Almond, P.R.; Bloch, C.D.; Chiu, C.; Fomytskyi, M.; Raischel, F.; Downer, M.; Tajima, T.

    2004-01-01

    Laser wakefield acceleration (LWFA) technology has evolved to where it should be evaluated for its potential as a future competitor to existing technology that produces electron and x-ray beams. The purpose of the present work is to investigate the dosimetric properties of an electron beam that should be achievable using existing LWFA technology, and to document the necessary improvements to make radiotherapy application for LWFA viable. This paper first qualitatively reviews the fundamental principles of LWFA and describes a potential design for a 30 cm accelerator chamber containing a gas target. Electron beam energy spectra, upon which our dose calculations are based, were obtained from a uniform energy distribution and from two-dimensional particle-in-cell (2D PIC) simulations. The 2D PIC simulation parameters are consistent with those reported by a previous LWFA experiment. According to the 2D PIC simulations, only approximately 0.3% of the LWFA electrons are emitted with an energy greater than 1 MeV. We studied only the high-energy electrons to determine their potential for clinical electron beams of central energy from 9 to 21 MeV. Each electron beam was broadened and flattened by designing a dual scattering foil system to produce a uniform beam (103%>off-axis ratio>95%) over a 25x25 cm2 field. An energy window (ΔE) ranging from 0.5 to 6.5 MeV was selected to study central-axis depth dose, beam flatness, and dose rate. Dose was calculated in water at a 100 cm source-to-surface distance using the EGS/BEAM Monte Carlo algorithm. Calculations showed that the beam flatness was fairly insensitive to ΔE. However, since the falloff of the depth-dose curve (R 10 -R 90 ) and the dose rate both increase with ΔE, a tradeoff between minimizing (R 10 -R 90 ) and maximizing dose rate is implied. If ΔE is constrained so that R 10 -R 90 is within 0.5 cm of its value for a monoenergetic beam, the maximum practical dose rate based on 2D PIC is approximately 0.1 Gy min-1

  16. Ultra-High-Contrast Laser Acceleration of Relativistic Electrons in Solid Targets

    Science.gov (United States)

    Higginson, Drew Pitney

    The cone-guided fast ignition approach to Inertial Confinement Fusion requires laser-accelerated relativistic electrons to deposit kilojoules of energy within an imploded fuel core to initiate fusion burn. One obstacle to coupling electron energy into the core is the ablation of material, known as preplasma, by laser energy proceeding nanoseconds prior to the main pulse. This causes the laser-absorption surface to be pushed back hundreds of microns from the initial target surface; thus increasing the distance that electrons must travel to reach the imploded core. Previous experiments have shown an order of magnitude decrease in coupling into surrogate targets when intentionally increasing the amount of preplasma. Additionally, for electrons to deposit energy within the core, they should have kinetic energies on the order of a few MeV, as less energetic electrons will be stopped prior to the core and more energetic electrons will pass through the core without depositing much energy. Thus a quantitative understanding of the electron energy spectrum and how it responds to varied laser parameters is paramount for fast ignition. For the first time, this dissertation quantitatively investigates the acceleration of electrons using an ultra-high-contrast laser. Ultra-high-contrast lasers reduce the laser energy that reaches the target prior to the main pulse; drastically reducing the amount of preplasma. Experiments were performed in a cone-wire geometry relevant to fast ignition. These experiments irradiated the inner-tip of a Au cone with the laser and observed electrons that passed through a Cu wire attached to the outer-tip of the cone. The total emission of Kalpha x-rays is used as a diagnostic to infer the electron energy coupled into the wire. Imaging the x-ray emission allowed an effective path-length of electrons within the wire to be determined, which constrained the electron energy spectrum. Experiments were carried out on the ultra-high-contrast Trident laser

  17. The Study of Advanced Accelerator Physics Research at UCLA Using the ATF at BNL: Vacuum Acceleration by Laser of Free Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Cline, David B. [Univ. of California, Los Angeles, CA (United States)

    2016-09-07

    An experiment was designed and data were taken to demonstrate that a tightly focused laser on vacuum can accelerate an electron beam in free space. The experiment was proof-of-principle and showed a clear effect for the laser beam off and on. The size of the effect was about 20% and was consistent over 30 laser and beam shots.

  18. Feasibility of Optical Transition Radiation Imaging for Laser-driven Plasma Accelerator Electron-Beam Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Rule, D. W. [Unlisted, US, MD; Downer, M. C. [Texas U.

    2017-10-09

    We report the initial considerations of using linearly polarized optical transition radiation (OTR) to characterize the electron beams of laser plasma accelerators (LPAs) such as at the Univ. of Texas at Austin. The two LPAs operate at 100 MeV and 2-GeV, and they currently have estimated normalized emittances at ~ 1-mm mrad regime with beam divergences less than 1/γ and beam sizes to be determined at the micron level. Analytical modeling results indicate the feasibility of using these OTR techniques for the LPA applications.

  19. A microwiggler Free-Electron Laser at the Brookhaven Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.; Gallardo, J.; Kirk, H.; Pellegrini, C.; van Steenbergen, A.; Bhowmik, A.; Rockwell International Corp., Canoga Park, CA

    1989-01-01

    We report the design and status of an FEL experiment at the Brookhaven National Laboratory Accelerator Test Facility. A 50 MeV high brightness electron beam will be utilized for an oscillator experiment in the visible wavelength region. The microwiggler to be used is a superferric planar undulator with a 0.88 cm period, 60 cm length and K = 0.35. The optical cavity is a 368 cm long stable resonator with broadband dielectric coated mirrors. 8 refs., 2 figs., 4 tabs

  20. A low-jitter pulse generator for a Van de Graaff electron accelerator

    Science.gov (United States)

    Janata, E.

    The design of a new pulse generator used to drive the electron gun of a Van de Graaff accelerator is described. It consists of a pulse amplifier and a remote control unit. Both units are interconnected by means of two fiber optic cables by which the beam pulse parameters, i.e. pulse start, duration and amplitude, are conveyed. The duration and the amplitude are continuously variable from 2 ns to 1 μs and from 0 to 1.5 A, respectively. The overall time jitter is about 1 ns.