An active particle accelerator

International Nuclear Information System (INIS)

Goldman, T.

1991-01-01

Although a static charge is difficult to maintain on macroscopic particles, it is straightforward to construct a small object with a regularly oscillating electric dipole moment. For objects of a given size, one may then construct an accelerator by appropriately matching the frequency and separations of an external array of electrodes to this size. Physically feasible size ranges, an accelerator design, and possible applications of such systems are discussed. 8 refs., 9 figs

Klystron life results in particle accelerator applications

International Nuclear Information System (INIS)

Bohlen, Heinz

2002-01-01

Based on reports contributed by various particle accelerator sites, among them DESY, CERN, and LANL, Weibull life time characteristics have been calculated for the klystrons used at these institutions. Supported by evaluations of the technologies and the operational conditions involved, the results, sometimes surprising and unexpected, present material that can be valuable for logistic considerations, the planning of future accelerators, and naturally for the design of future klystrons

Superconductivity in high energy particle accelerators

International Nuclear Information System (INIS)

Schmueser, P.

2002-08-01

The basics of superconductivity are outlined with special emphasis on the features which are relevant for the application in magnets and radio frequency cavities for high energy particle accelerators. The special properties of superconducting accelerator magnets are described in detail: design principles, magnetic field calculations, magnetic forces, quench performance, persistent magnetization currents and eddy currents. The design principles and basic properties of superconducting cavities are explained as well as the observed performance limitations and the countermeasures. The ongoing research efforts towards maximum accelerating fields are addressed and the coupling of radio frequency power to the particle beam is treated. (orig.)

Industrial accelerators and their applications

CERN Document Server

Hamm, Marianne E

2012-01-01

This unique new book is a comprehensive review of the many current industrial applications of particle accelerators, written by experts in each of these fields. Readers will gain a broad understanding of the principles of these applications, the extent to which they are employed, and the accelerator technology utilized. The book also serves as a thorough introduction to these fields for non-experts and laymen. Due to the increased interest in industrial applications, there is a growing interest among accelerator physicists and many other scientists worldwide in understanding how accelerators are used in various applications. The government agencies that fund scientific research with accelerators are also seeking more information on the many commercial applications that have been or can be developed with the technology developments they are funding. Many industries are also doing more research on how they can improve their products or processes using particle beams.

Nonlinear dynamics aspects of particle accelerators

International Nuclear Information System (INIS)

Jowett, J.M.; Turner, S.; Month, M.

1986-01-01

These proceedings contain the lectures presented at the named winter school. They deal with the application of dynamical systems to accelerator theory. Especially considered are the statistical description of charged-beam plasmas, integrable and nonintegrable Hamiltonian systems, single particle dynamics and nonlinear resonances in circular accelerators, nonlinear dynamics aspects of modern storage rings, nonlinear beam-beam resonances, synchro-betatron resonances, observations of the beam-beam interactions, the dynamics of the beam-beam interactions, beam-beam simulations, the perturbation method in nonlinear dynamics, theories of statistical equilibrium in electron-positron storage rings, nonlinear dissipative phenomena in electron storage rings, the dynamical aperture, the transition to chaos for area-preserving maps, special processors for particle tracking, algorithms for tracking of charged particles in circular accelerators, the breakdown of stability, and a personal perspective of nonlinear dynamics. (HSI)

Safety guidance and inspection program for particle accelerator

Energy Technology Data Exchange (ETDEWEB)

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

2001-03-15

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

Recent progress in particle accelerators

International Nuclear Information System (INIS)

Cole, F.T.; Mills, F.E.

1988-01-01

Many accelerators have also been built for medical radiography and therapy. Electron accelerators for this application are available commercially, using the electrons directly or bremsstrahlung photons. Neutrons produced by accelerator beams have also been used for therapy with considerable success, and several proton accelerators built for physics research have been adapted for direct therapy with protons. The first proton accelerator specifically for therapy is now being built. Separate from what might be called conventional accelerator technology, an entirely new field utilizing very highly pulsed power has been developed, and beams of short pulses of thousands or millions of amperes peak current in the MeV energy range are now available. These beams have important applications in high-energy particle acceleration, controlled fusion, industrial treatment of materials, and possibly in food preservation. All of these accelerators make use of external fields of acceleration. There is also vigorous research into new methods of acceleration, in many schemes making use of the intense accelerating fields, generated by laser beams or by plasma states of matter. This research has not as yet made traditional kinds of accelerators outmoded, but many workers hope that early in the next century there will be practical new acceleration methods making use of these very high fields. These developments are discussed in detail

Accelerators of atomic particles

International Nuclear Information System (INIS)

Sarancev, V.

1975-01-01

A brief survey is presented of accelerators and methods of accelerating elementary particles. The principle of collective accelerating of elementary particles is clarified and the problems are discussed of its realization. (B.S.)

Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory and Astrophysical Applications

International Nuclear Information System (INIS)

Matthaeus, W.; Brown, M.

2006-01-01

This is the final technical report for a funded program to provide theoretical support to the Swarthmore Spheromak Experiment. We examined mhd relaxation, reconnecton between two spheromaks, particle acceleration by these processes, and collisonless effects, e.g., Hall effect near the reconnection zone,. Throughout the project, applications to space plasma physics and astrophysics were included. Towards the end of the project we were examining a more fully turbulent relaxation associated with unconstrained dynamics in SSX. We employed experimental, spacecraft observations, analytical and numerical methods.

Accelerator Technology: Geodesy and Alignment for Particle Accelerators

CERN Document Server

Missiaen, D

2013-01-01

This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '8.9 Geodesy and Alignment for Particle Accelerators' of the Chapter '8 Accelerator Technology' with the content: 8.9 Geodesy and Alignment for Particle Accelerators 8.9.1 Introduction 8.9.2 Reference and Co-ordinate Systems 8.9.3 Definition of the Beam Line on the Accelerator Site 8.9.4 Geodetic Network 8.9.5 Tunnel Preliminary Works 8.9.6 The Alignment References 8.9.7 Alignment of Accelerator Components 8.9.8 Permanent Monitoring and Remote Alignment of Low Beta Quadrupoles 8.9.9 Alignment of Detector Components

Charged particle accelerators for inertial fusion energy

International Nuclear Information System (INIS)

Humphries, S. Jr.

1991-01-01

The long history of successful commercial applications of charged-particle accelerators is largely a result of initiative by private industry. The Department of Energy views accelerators mainly as support equipment for particle physicists rather than components of an energy generation program. In FY 91, the DOE spent over 850 M$ on building and supporting accelerators for physics research versus 5 M$ on induction accelerators for fusion energy. The author believes this emphasis is skewed. One must address problems of long-term energy sources to preserve the possibility of basic research by future generations. In this paper, the author reviews the rationale for accelerators as inertial fusion drivers, emphasizing that these devices provide a viable path of fusion energy from viewpoints of both physics and engineering. In this paper, he covered the full range of accelerator fusion applications. Because of space limitations, this paper concentrates on induction linacs for ICF, an approach singled out in recent reports by the National Academy of Sciences and the Fusion Policy Advisory Committee as a promising path to long-term fusion power production. Review papers by Cook, Leung, Franzke, Hofmann and Reiser in these proceedings give details on light ion fusion and RF accelerator studies

Nonlinear dynamics aspects of particle accelerators. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Jowett, J M; Turner, S; Month, M

1986-01-01

These proceedings contain the lectures presented at the named winter school. They deal with the application of dynamical systems to accelerator theory. Especially considered are the statistical description of charged-beam plasmas, integrable and nonintegrable Hamiltonian systems, single particle dynamics and nonlinear resonances in circular accelerators, nonlinear dynamics aspects of modern storage rings, nonlinear beam-beam resonances, synchro-betatron resonances, observations of the beam-beam interactions, the dynamics of the beam-beam interactions, beam-beam simulations, the perturbation method in nonlinear dynamics, theories of statistical equilibrium in electron-positron storage rings, nonlinear dissipative phenomena in electron storage rings, the dynamical aperture, the transition to chaos for area-preserving maps, special processors for particle tracking, algorithms for tracking of charged particles in circular accelerators, the breakdown of stability, and a personal perspective of nonlinear dynamics. (HSI).

Accelerator structure for a charged particle linear accelerator working in standing wave mode

International Nuclear Information System (INIS)

Tran, D.T.; Tronc, Dominique.

1977-01-01

Charged particle accelerators generally include a pre-grouping or pre-accelerating structure associated with the accelerator structure itself. But pre-grouping or pre-accelerating structures of known type (Patent application No. 70 39261 for example) present electric and dimensional characteristics that rule them out for accelerators working at high frequencies (C or X bands for example), since the distance separating the interaction spaces becomes very small in this case. The accelerator structure mentioned in this invention can be used to advantage for such accelerators [fr

Modeling of Particle Acceleration at Multiple Shocks Via Diffusive Shock Acceleration: Preliminary Results

Science.gov (United States)

Parker, L. N.; Zank, G. P.

2013-12-01

Successful forecasting of energetic particle events in space weather models require algorithms for correctly predicting the spectrum of ions accelerated from a background population of charged particles. We present preliminary results from a model that diffusively accelerates particles at multiple shocks. Our basic approach is related to box models (Protheroe and Stanev, 1998; Moraal and Axford, 1983; Ball and Kirk, 1992; Drury et al., 1999) in which a distribution of particles is diffusively accelerated inside the box while simultaneously experiencing decompression through adiabatic expansion and losses from the convection and diffusion of particles outside the box (Melrose and Pope, 1993; Zank et al., 2000). We adiabatically decompress the accelerated particle distribution between each shock by either the method explored in Melrose and Pope (1993) and Pope and Melrose (1994) or by the approach set forth in Zank et al. (2000) where we solve the transport equation by a method analogous to operator splitting. The second method incorporates the additional loss terms of convection and diffusion and allows for the use of a variable time between shocks. We use a maximum injection energy (Emax) appropriate for quasi-parallel and quasi-perpendicular shocks (Zank et al., 2000, 2006; Dosch and Shalchi, 2010) and provide a preliminary application of the diffusive acceleration of particles by multiple shocks with frequencies appropriate for solar maximum (i.e., a non-Markovian process).

Plasma based charged-particle accelerators

International Nuclear Information System (INIS)

Bingham, R; Mendonca, J T; Shukla, P K

2004-01-01

Studies of charged-particle acceleration processes remain one of the most important areas of research in laboratory, space and astrophysical plasmas. In this paper, we present the underlying physics and the present status of high gradient and high energy plasma accelerators. We will focus on the acceleration of charged particles to relativistic energies by plasma waves that are created by intense laser and particle beams. The generation of relativistic plasma waves by intense lasers or electron beams in plasmas is important in the quest for producing ultra-high acceleration gradients for accelerators. With the development of compact short pulse high brightness lasers and electron positron beams, new areas of studies for laser/particle beam-matter interactions is opening up. A number of methods are being pursued vigorously to achieve ultra-high acceleration gradients. These include the plasma beat wave accelerator mechanism, which uses conventional long pulse (∼100 ps) modest intensity lasers (I ∼ 10 14 -10 16 W cm -2 ), the laser wakefield accelerator (LWFA), which uses the new breed of compact high brightness lasers ( 10 18 W cm -2 , the self-modulated LWFA concept, which combines elements of stimulated Raman forward scattering, and electron acceleration by nonlinear plasma waves excited by relativistic electron and positron bunches. In the ultra-high intensity regime, laser/particle beam-plasma interactions are highly nonlinear and relativistic, leading to new phenomena such as the plasma wakefield excitation for particle acceleration, relativistic self-focusing and guiding of laser beams, high-harmonic generation, acceleration of electrons, positrons, protons and photons. Fields greater than 1 GV cm -1 have been generated with particles being accelerated to 200 MeV over a distance of millimetre. Plasma wakefields driven by positron beams at the Stanford Linear Accelerator Center facility have accelerated the tail of the positron beam. In the near future

Non-isochronous spiral orbit particle accelerator and fixed frequency closed orbit particle accelerator

International Nuclear Information System (INIS)

Fujisawa, Takashi; Hattori, Toshiyuki

2006-01-01

One of the present inventions provides a spiral orbit charged particle accelerator in which the magnetic field increases as the radius increases more rapidly than an isochronous magnetic field distribution, and the distribution of fixed-frequency accelerating RF voltage is formed so that a harmonic number changes in integer for every particle revolution. The other invention realizes to make the closed orbit charged particle accelerator having a fixed frequency amplitude modulator that is able to modulate amplitude of the RF voltage so that a harmonic number decreases in integer in an every particle revolution. (author)

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.

Acceleration of polarized particles

International Nuclear Information System (INIS)

Buon, J.

1992-05-01

The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

Cryogenics for Particle Accelerators and Detectors

CERN Document Server

Lebrun, P; Vandoni, Giovanna; Wagner, U

2002-01-01

Cryogenics has become a key ancillary technology of particle accelerators and detectors, contributing to their sustained development over the last fifty years. Conversely, this development has produced new challenges and markets for cryogenics, resulting in a fruitful symbiotic relation which materialized in significant technology transfer and technical progress. This began with the use of liquid hydrogen and deuterium in the targets and bubble chambers of the 1950s, 1960s and 1970s. It developed more recently with increasing amounts of liquefied noble gases - mainly argon, but also krypton and even today xenon - in calorimeters. In parallel with these applications, the availability of practical type II superconductors from the early 1960s triggered the use of superconductivity in large spectrometer magnets - mostly driven by considerations of energy savings - and the corresponding development of helium cryogenics. It is however the generalized application of superconductivity in particle accelerators - RF ac...

Accelerators for research and applications

International Nuclear Information System (INIS)

Alonso, J.R.

1990-06-01

The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs

Particle Accelerators: Activities and Developments in the CIEMAT

International Nuclear Information System (INIS)

Garcia Tabares, L.; Toral Fernandez, F.

2010-01-01

Although they have been in use for many years, particle accelerators are machines in constant evolution with a growing number of applications. They are not only used in basic science to understand the structure of matter, but they also have multiple technological, medical and analytical applications, etc. This fact led the CIEMAT to create the Accelerator Unit in late 2008, as part of the Technology department. Although the group had been carrying out accelerator-related activities for some time, the aim of creating the Unit was to develop not only accelerator components but also complete systems. This article contains a brief introduction to accelerators and also describes the current activities in our Unit. (Author) 8 refs.

Application of carbon fiber composite materials for the collision sections of particle accelerators

International Nuclear Information System (INIS)

Betzold, H.; Lippmann, G.

1991-01-01

Components made of carbon fiber composite material (CFCM) with Epoxy or BMI matrix were designed for various applications such as vacuum tubes, vertex chambers or support structures. The outstanding properties of CFCM which in many aspects are superior to metal structures especially qualify CFCM components for use in the collision sections of particle accelerators. A total of some 50 m of CFCM beam-tubes and of around 20 different CFCM structures and support elements of various configurations were produced following the specific needs and requirements of high energy particle physics at CERN, DESY and several other research institutes

Particle acceleration in modified shocks

Energy Technology Data Exchange (ETDEWEB)

Drury, L.O' C. (Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany, F.R.)); Axford, W.I. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.)); Summers, D. (Memorial Univ. of Newfoundland, St. John' s (Canada))

1982-03-01

Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed.

Particle acceleration in modified shocks

International Nuclear Information System (INIS)

Drury, L.O'C.; Axford, W.I.; Summers, D.

1982-01-01

Efficient particle acceleration in shocks must modify the shock structure with consequent changes in the particle acceleration. This effect is studied and analytic solutions are found describing the diffusive acceleration of particles with momentum independent diffusion coefficients in hyperbolic tangent type velocity transitions. If the input particle spectrum is a delta function, the shock smoothing replaces the truncated power-law downstream particle spectrum by a more complicated form, but one which has a power-law tail at high momenta. For a cold plasma this solution can be made completely self-consistent. Some problems associated with momentum dependent diffusion coefficients are discussed. (author)

Review of Compact Commercial Accelerator Products and Applications.

Science.gov (United States)

Jongen, Y.

1997-05-01

Historically, particle accelerators were developed initially for nuclear, then for particle physics research. From this research resulted applications of accelerators in the field of medicine and industry. These application-oriented accelerators are generally built commercially, and they often emphasize other qualities than the accelerators for research. The research applications frequently require energies or beam qualities at the limit of the existing technologies. They offer the largest flexibility in term of particles and beam properties, but are more complex, more expensive and often require large and highly qualified staff to operate and maintain them. In contrast, most applications are done with low to moderate energy protons or electrons, but often with large average beam power. The accelerators are generally specialized for a specific application, and are therefore very simple and inexpensive to operate. The author will review some applications in the field of medicine, such as the production of radio-isotopes for medical diagnostic or the production of electrons, protons or fast neutron beams for cancer therapy. In the industrial field, high power electron beam are used for sterilization and for the modification of materials. Log No. 1001

Licensing criteria for particle accelerators categorization

International Nuclear Information System (INIS)

Costa, Evaldo L.C. da

2013-01-01

From the international experience of research centers in various parts of the world, where there are particle accelerators of various sizes and energies, it was found that operating energy of particle accelerators is one of the parameters used by categorization models in the licensing of these radiation facilities, and the facility size is an important aspect to be considered in this model. A categorization based on these two key parameters is presented, also taking into account the kinds of accelerated particles and radiation produced, the operating related technology and the possible applications concerned. The categorization models of national nuclear authorities of five countries are reviewed, emphasizing the contribution of Brazil, and the new model proposed is also based on the experience of these countries, modified by those two parameter discussed above: facility size and operating energy of particle accelerators. Later, some changes are suggested, considering risk factors and safety features related to these facilities, emphasizing some analytical tools commonly used in nuclear facilities and chemical plants, such as: risk-informing decision making, layer of protection analysis (LOPRA) and safety integrity levels (SIL), the two latter ones having its origin in the broader concept of system safety. We also discuss the problem of scarcity of reliability data (common in the analyses involving risk factors and safety), due to security concerns and other factors, being the possible alternative solutions the use of generic databases and the adoption of reference facilities that provide partial data publicly. (author).

Licensing criteria for particle accelerators categorization

Energy Technology Data Exchange (ETDEWEB)

Costa, Evaldo L.C. da, E-mail: evaldo@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN-RJ), Rio de Janeiro, RJ (Brazil). Dir. de Radioprotecao e Seguranca; Melo, Paulo F.F. Frutuoso e, E-mail: frutuoso@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

2013-07-01

From the international experience of research centers in various parts of the world, where there are particle accelerators of various sizes and energies, it was found that operating energy of particle accelerators is one of the parameters used by categorization models in the licensing of these radiation facilities, and the facility size is an important aspect to be considered in this model. A categorization based on these two key parameters is presented, also taking into account the kinds of accelerated particles and radiation produced, the operating related technology and the possible applications concerned. The categorization models of national nuclear authorities of five countries are reviewed, emphasizing the contribution of Brazil, and the new model proposed is also based on the experience of these countries, modified by those two parameter discussed above: facility size and operating energy of particle accelerators. Later, some changes are suggested, considering risk factors and safety features related to these facilities, emphasizing some analytical tools commonly used in nuclear facilities and chemical plants, such as: risk-informing decision making, layer of protection analysis (LOPRA) and safety integrity levels (SIL), the two latter ones having its origin in the broader concept of system safety. We also discuss the problem of scarcity of reliability data (common in the analyses involving risk factors and safety), due to security concerns and other factors, being the possible alternative solutions the use of generic databases and the adoption of reference facilities that provide partial data publicly. (author).

Advanced Accelerator Applications in Medicine

International Nuclear Information System (INIS)

Rimjiaem, Sakhorn

2015-01-01

besides the original purpose on development of particle acceleratora as research tools in nuclear and high-energy physics, there are large variety of accelerators used in various fileds from fundamental research to industrial usesand applications chemistry, biology and medicine. Pratical accelators used in various field of medical applications since serveral decades. Even through, a large fraction of applications is emphasized on cancer therappy, the number of accelerators used in midicine for other diagnostics and treatments has increased steady over the years. Several types of accelerated particles are used including electron, proton, neutron and ions. Presently, relativistic electron beams and radiation from linear accelerators (linas) are widely used. A combination of positron emission tomography (PRT) and radiotherapy is an example of excellent invention early detection and treat of cancer tumors. The most developments for proton and heavy ion therapy as well as a modern boron neutron capture therapy (BNCT) are also great incoming effective systems. This talk will focus on developments of the accelrator systems as well as overview on biophysical properties and medical aspects of the diacnostics and treatments.

Low energy accelerators for research and applications

International Nuclear Information System (INIS)

Bhandari, R.K.

2013-01-01

Charged particle accelerators are instruments for producing a variety of radiations under controlled conditions for basic and applied research as well as applications. They have helped enormously to study the matter, atoms, nuclei, sub-nuclear particles and their constituents, forces involved in the related phenomena etc. No other man-made instrument has been so effective in such studies as the accelerator. The large accelerator constructed so far is the Large Hadron Collider (LHC) housed in a tunnel of 27 km circumference, while a small accelerator can fit inside a room. Small accelerators accelerate charged particles such as electrons, protons, deuterons, alphas and, in general ions to low energy, generally, below several MeV. These particle beams are used for studies in nuclear astrophysics, atomic physics, material science, surface physics, bio sciences etc. They are used for ion beam analysis such as RBS, PIXE, NRA, AMS, CPAA etc. More importantly, the ion beams have important industrial applications like ion implantation, surface modification, isotope production etc. while electron beams are used for material processing, material modification, sterilization, food preservation, non destructive testing etc. In this talk, role of low energy accelerators in research and industry as well as medicine will be discussed. (author)

Slow waves in microchannel metal waveguides and application to particle acceleration

Directory of Open Access Journals (Sweden)

L. C. Steinhauer

2003-06-01

Full Text Available Conventional metal-wall waveguides support waveguide modes with phase velocities exceeding the speed of light. However, for infrared frequencies and guide dimensions of a fraction of a millimeter, one of the waveguide modes can have a phase velocity equal to or less than the speed of light. Such a metal microchannel then acts as a slow-wave structure. Furthermore, if it is a transverse magnetic mode, the electric field has a component along the direction of propagation. Therefore, a strong exchange of energy can occur between a beam of charged particles and this slow-waveguide mode. Moreover, the energy exchange can be sustained over a distance limited only by the natural damping of the wave. This makes the microchannel metal waveguide an attractive possibility for high-gradient electron laser acceleration because the wave can be directly energized by a long-wavelength laser. Indeed the frequency of CO_{2} lasers lies at a fortuitous wavelength that produces a strong laser-particle interaction in a channel of reasonable macroscopic size (e.g., ∼0.6  mm. The dispersion properties including phase velocity and damping for the slow wave are developed. The performance and other issues related to laser accelerator applications are discussed.

Slow waves in microchannel metal waveguides and application to particle acceleration

Science.gov (United States)

Steinhauer, L. C.; Kimura, W. D.

2003-06-01

Conventional metal-wall waveguides support waveguide modes with phase velocities exceeding the speed of light. However, for infrared frequencies and guide dimensions of a fraction of a millimeter, one of the waveguide modes can have a phase velocity equal to or less than the speed of light. Such a metal microchannel then acts as a slow-wave structure. Furthermore, if it is a transverse magnetic mode, the electric field has a component along the direction of propagation. Therefore, a strong exchange of energy can occur between a beam of charged particles and this slow-waveguide mode. Moreover, the energy exchange can be sustained over a distance limited only by the natural damping of the wave. This makes the microchannel metal waveguide an attractive possibility for high-gradient electron laser acceleration because the wave can be directly energized by a long-wavelength laser. Indeed the frequency of CO2 lasers lies at a fortuitous wavelength that produces a strong laser-particle interaction in a channel of reasonable macroscopic size (e.g., ˜0.6 mm). The dispersion properties including phase velocity and damping for the slow wave are developed. The performance and other issues related to laser accelerator applications are discussed.

Particle acceleration by electromagnetic pulses

International Nuclear Information System (INIS)

Lai, H.M.

1982-01-01

Particle interaction with plane electromagnetic pulses is studied. It is shown that particle acceleration by a wavy pulse, depending on the shape of the pulse, may not be small. Further, a diffusive-type particle acceleration by multiple weak pulses is described and discussed. (author)

VEDs for charged particle accelerators: Indian scenario

International Nuclear Information System (INIS)

Bhandari, R.K.

2012-01-01

In the initial times after their invention, the charged particle accelerators have, primarily, been used for fundamental studies on nuclei and atoms. From the first modern accelerator, the cathode ray tube, used by J.J. Thomson for the discovery of electron, very recently the gigantic 27 km circumference Large Hadron Collider (LHC) is operational in the search of Higg's boson and related physics issues. Particle accelerators have emerged as powerful microscopes for investigating the finest details of cells, genes, molecules, atoms, protons, neutrons, muons, electrons, quarks and, possibly, still undiscovered even more fundamental constituents of the universe, such as dark matter and dark energy. Several noble prize winning discoveries have been made using accelerators. Accelerators are now being used in a wide area of industrial and medical applications. They are used for the production of radioisotopes for medical imaging, cancer therapy, food sterilization, treatment of waste water, sterilization of medical equipment, material modification, mass spectroscopy, cargo scanning, fabrication of semiconductors etc. Ongoing effort towards the development of accelerators with megawatt beam power is showing hope for a cleaner source of nuclear energy and treatment of nuclear waste. Several tens of thousands of accelerators are presently operational in the world for basic research and applications. Development of new accelerators has several times been driven by new technologies and materials and sometimes they have driven the technological developments towards cutting edge. Some examples are ultra-high vacuum in large volumes, superfluid helium in cryogenics, cryocoolers, superconducting magnets and RF cavities, high power vacuum electronic devices, global control systems, superfast computing and communication networks, giant data storage/processing systems etc. India has been pursuing a fairly robust programme of accelerator development at various institutions. It

Technology and applications of advanced accelerator concepts

CERN Document Server

Chou, Weiren

2016-01-01

Since its invention in the 1920s, particle accelerators have made tremendous progress in accelerator science, technology and applications. However, the fundamental acceleration principle, namely, to apply an external radiofrequency (RF) electric field to accelerate charged particles, remains unchanged. As this method (either room temperature RF or superconducting RF) is approaching its intrinsic limitation in acceleration gradient (measured in MeV/m), it becomes apparent that new methods with much higher acceleration gradient (measured in GeV/m) must be found for future very high energy accelerators as well as future compact (table-top or room-size) accelerators. This volume introduces a number of advanced accelerator concepts (AAC) — their principles, technologies and potential applications. For the time being, none of them stands out as a definitive direction in which to go. But these novel ideas are in hot pursuit and look promising. Furthermore, some AAC requires a high power laser system. This has the ...

Linear particle accelerator

International Nuclear Information System (INIS)

Richards, J.A.

1977-01-01

A linear particle accelerator which provides a pulsed beam of charged particles of uniform energy is described. The accelerator is in the form of an evacuated dielectric tube, inside of which a particle source is located at one end of the tube, with a target or window located at the other end of the dielectric tube. Along the length of the tube are externally located pairs of metal plates, each insulated from each other in an insulated housing. Each of the plates of a pair are connected to an electrical source of voltage of opposed polarity, with the polarity of the voltage of the plates oriented so that the plate of a pair, nearer to the particle source, is of the opposed polarity to the charge of the particle emitted by the source. Thus, a first plate about the tube located nearest the particle source, attracts a particle which as it passes through the tube past the first plate is then repelled by the reverse polarity of the second plate of the pair to continue moving towards the target

Delivery of single accelerated particles

International Nuclear Information System (INIS)

McNulty, P.J.; Pease, V.P.; Bond, V.P.; Schimmerling, W.; Vosburgh, K.G.; Crebbin, K.; Everette, W.; Howard, J.

1978-01-01

It is desirable for certain experiments involving accelerators to have the capability of delivering just a single beam particle to the target area. The essential features of such a one-at-a-time facility are discussed. Two such facilities are described which were implemented at high-energy heavy ion accelerators without having to make major structural changes in the existing beam lines or substantially interfering with other accelerator uses. Two accelerator facilities are described which had the capability of delivering a single beam particle to the target area. This feature is necessary in certain experiments investigating visual phenomena induced by charged particles, other single particle interactions in biology, and other experiments in which the low intensities of cosmic rays need to be simulated. Both facilities were implemented without having to make structural changes in the existing beam lines or substantially interfering with other accelerator uses. (Auth.)

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.

Particle acceleration in pulsar magnetospheres

International Nuclear Information System (INIS)

Baker, K.B.

1978-10-01

The structure of pulsar magnetospheres and the acceleration mechanism for charged particles in the magnetosphere was studied, using a pulsar model which required large acceleration of the particles near the surface of the star. A theorem was developed which showed that particle acceleration cannot be expected when the angle between the magnetic field lines and the rotation axis is constant (e.g. radial field lines). If this angle is not constant, however, acceleration must occur. The more realistic model of an axisymmetric neutron star with a strong dipole magnetic field aligned with the rotation axis was investigated. In this case, acceleration occurred at large distances from the surface of the star. The magnitude of the current can be determined using the model presented. In the case of nonaxisymmetric systems, the acceleration is expected to occur nearer to the surface of the star

Electrostatic accelerators fundamentals and applications

CERN Document Server

2005-01-01

Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

Electron accelerators: History, applications, and perspectives

International Nuclear Information System (INIS)

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

2014-01-01

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

CAS CERN Accelerator School superconductivity in particle accelerators

International Nuclear Information System (INIS)

Turner, S.

1989-01-01

One of the objectives of the CERN Accelerator School is to run courses on specialised topics in the particle accelerator field. The present volume contains the proceedings of one such course, this time organized in conjunction with the Deutsches Elektronen Synchrotron (DESY) on the subject of superconductivity in particle accelerators. This course reflects the very considerable progress made over the last few years in the use of the technology for the magnet and radio-frequency systems of many large and small accelerators already in use or nearing completion, while also taking account of the development work now going on for future machines. The lectures cover the theory of superconductivity, cryogenics and accelerator magnets and cavities, while the seminars include superfluidity, superconductors, special magnets and the prospects for high-temperature superconductors. (orig.)

Particle-in-cell/accelerator code for space-charge dominated beam simulation

Energy Technology Data Exchange (ETDEWEB)

2012-05-08

Warp is a multidimensional discrete-particle beam simulation program designed to be applicable where the beam space-charge is non-negligible or dominant. It is being developed in a collaboration among LLNL, LBNL and the University of Maryland. It was originally designed and optimized for heave ion fusion accelerator physics studies, but has received use in a broader range of applications, including for example laser wakefield accelerators, e-cloud studies in high enery accelerators, particle traps and other areas. At present it incorporates 3-D, axisymmetric (r,z) planar (x-z) and transverse slice (x,y) descriptions, with both electrostatic and electro-magnetic fields, and a beam envelope model. The code is guilt atop the Python interpreter language.

New particle accelerations by magnetized plasma shock waves

International Nuclear Information System (INIS)

Takeuchi, Satoshi

2005-01-01

Three mechanisms concerning particle accelerations are proposed to account for the high energy of cosmic rays. A model of magnetized plasma clouds is used to simulate a shock-type wave. The attainable energies of test particles colliding with the moving magnetic clouds are investigated by analytical and numerical methods for the three mechanisms. The magnetic trapping acceleration is a new type of particle trapping and acceleration in which, in principle, the test particle is accelerated indefinitely; hence, this mechanism surpasses the Fermi-type acceleration. In the single-step acceleration, the test particle obtains a significant energy gain even though it only experiences a single collision. Lastly, there is the bouncing acceleration by which the test particle is substantially accelerated due to repeated collisions

Particle accelerators and lasers high energy sources

International Nuclear Information System (INIS)

Watteau, J.P.

1985-04-01

Particle accelerators and lasers are to-day precious devices for physicist and engineer. Their performance and scope do not stop growing. Producing thin beams of high energy particles or photons, they are able to be very high energy sources which interact strongly with matter. Numerous applications use them: research, industry, communication, medicine, agroalimentary, defence, and soon. In this note, their operation principles are described and some examples of their use as high energy sources are given [fr

Particle acceleration in the interplanetary space

International Nuclear Information System (INIS)

Tverskoj, B.A.

1983-01-01

A review on the problem of particle acceleration in the interplanetary space is given. The main lationship attention is paid to the problem of the re/ between the impact- and turbulent acceleration when an undisturbed magnetic field forms not too small angle THETA > 10 deg with the shock wave front. The following conclusions are drawn. Particle acceleration at the shock wave front is manifested in the explicit form, if the shock wave propagates along a homogeneous (in the 11 cm range) solar wind. The criterion of such an acceleration is the exponential distribution function F approximately vsup(-ν) (v is the particle velocity and ν is the accelerated particle spectrum index) in the low energy range and the conservation of this function at considerable distances behind the front. The presence of an additional turbulent acceleration behind the front is manifested in decreasing ν down to approximately 3.5 in the low energy range and in the spectrum evolution behind the front

Laser and Particle Guiding Micro-Elements for Particle Accelerators

CERN Document Server

Plettner, Tomas; Spencer, James; Wisdom, Jeffrey

2005-01-01

Laser driven particle accelerators based on the current generation of lasers will require sub-micron control of the laser field as well as precise beam guiding. Hence the fabrication techniques that allow integrating both elements into an accelerator-on-chip format become critical for the success of such particle accelerators. Micromachining technology for silicon has been shown to be one such feasible technology in PAC2003 but with a variety of complications on the laser side. Fortunately, in recent years the fabrication of transparent ceramics has become an interesting technology that could be applied for laser-particle accelerators in several ways. We discuss this area, its advantages such as the range of materials it provides and various ways to implement it followed by some different test examples that have been considered. One important goal of this approach is an integrated system that could avoid the necessity of having to inject either laser or particle pulses into these structures.

Relativistic shocks and particle acceleration

International Nuclear Information System (INIS)

Heavens, A.F.

1988-01-01

In this paper, we investigate the fluid dynamics of relativistic shock waves, and use the results to calculate the spectral index of particles accelerated by the Fermi process in such shocks. We have calculated the distributions of Fermi-accelerated particles at shocks propagating into cold proton-electron plasma and also cold electron-positron plasma. We have considered two different power spectra for the scattering waves, and find, in contrast to the non-relativistic case, that the spectral index of the accelerated particles depends on the wave power spectrum. On the assumption of thermal equilibrium both upstream and downstream, we present some useful fits for the compression ratio of shocks propagating at arbitrary speeds into gas of any temperature. (author)

Current Fragmentation and Particle Acceleration in Solar Flares

Science.gov (United States)

Cargill, P. J.; Vlahos, L.; Baumann, G.; Drake, J. F.; Nordlund, Å.

2012-11-01

Particle acceleration in solar flares remains an outstanding problem in plasma physics and space science. While the observed particle energies and timescales can perhaps be understood in terms of acceleration at a simple current sheet or turbulence site, the vast number of accelerated particles, and the fraction of flare energy in them, defies any simple explanation. The nature of energy storage and dissipation in the global coronal magnetic field is essential for understanding flare acceleration. Scenarios where the coronal field is stressed by complex photospheric motions lead to the formation of multiple current sheets, rather than the single monolithic current sheet proposed by some. The currents sheets in turn can fragment into multiple, smaller dissipation sites. MHD, kinetic and cellular automata models are used to demonstrate this feature. Particle acceleration in this environment thus involves interaction with many distributed accelerators. A series of examples demonstrate how acceleration works in such an environment. As required, acceleration is fast, and relativistic energies are readily attained. It is also shown that accelerated particles do indeed interact with multiple acceleration sites. Test particle models also demonstrate that a large number of particles can be accelerated, with a significant fraction of the flare energy associated with them. However, in the absence of feedback, and with limited numerical resolution, these results need to be viewed with caution. Particle in cell models can incorporate feedback and in one scenario suggest that acceleration can be limited by the energetic particles reaching the condition for firehose marginal stability. Contemporary issues such as footpoint particle acceleration are also discussed. It is also noted that the idea of a "standard flare model" is ill-conceived when the entire distribution of flare energies is considered.

The Advanced Composition Explorer Shock Database and Application to Particle Acceleration Theory

Science.gov (United States)

Parker, L. Neergaard; Zank, G. P.

2015-01-01

The theory of particle acceleration via diffusive shock acceleration (DSA) has been studied in depth by Gosling et al. (1981), van Nes et al. (1984), Mason (2000), Desai et al. (2003), Zank et al. (2006), among many others. Recently, Parker and Zank (2012, 2014) and Parker et al. (2014) using the Advanced Composition Explorer (ACE) shock database at 1 AU explored two questions: does the upstream distribution alone have enough particles to account for the accelerated downstream distribution and can the slope of the downstream accelerated spectrum be explained using DSA? As was shown in this research, diffusive shock acceleration can account for a large population of the shocks. However, Parker and Zank (2012, 2014) and Parker et al. (2014) used a subset of the larger ACE database. Recently, work has successfully been completed that allows for the entire ACE database to be considered in a larger statistical analysis. We explain DSA as it applies to single and multiple shocks and the shock criteria used in this statistical analysis. We calculate the expected injection energy via diffusive shock acceleration given upstream parameters defined from the ACE Solar Wind Electron, Proton, and Alpha Monitor (SWEPAM) data to construct the theoretical upstream distribution. We show the comparison of shock strength derived from diffusive shock acceleration theory to observations in the 50 keV to 5 MeV range from an instrument on ACE. Parameters such as shock velocity, shock obliquity, particle number, and time between shocks are considered. This study is further divided into single and multiple shock categories, with an additional emphasis on forward-forward multiple shock pairs. Finally with regard to forward-forward shock pairs, results comparing injection energies of the first shock, second shock, and second shock with previous energetic population will be given.

Particle acceleration at a reconnecting magnetic separator

Science.gov (United States)

Threlfall, J.; Neukirch, T.; Parnell, C. E.; Eradat Oskoui, S.

2015-02-01

Context. While the exact acceleration mechanism of energetic particles during solar flares is (as yet) unknown, magnetic reconnection plays a key role both in the release of stored magnetic energy of the solar corona and the magnetic restructuring during a flare. Recent work has shown that special field lines, called separators, are common sites of reconnection in 3D numerical experiments. To date, 3D separator reconnection sites have received little attention as particle accelerators. Aims: We investigate the effectiveness of separator reconnection as a particle acceleration mechanism for electrons and protons. Methods: We study the particle acceleration using a relativistic guiding-centre particle code in a time-dependent kinematic model of magnetic reconnection at a separator. Results: The effect upon particle behaviour of initial position, pitch angle, and initial kinetic energy are examined in detail, both for specific (single) particle examples and for large distributions of initial conditions. The separator reconnection model contains several free parameters, and we study the effect of changing these parameters upon particle acceleration, in particular in view of the final particle energy ranges that agree with observed energy spectra.

Particle-accelerator decommissioning

International Nuclear Information System (INIS)

Opelka, J.H.; Mundis, R.L.; Marmer, G.J.; Peterson, J.M.; Siskind, B.; Kikta, M.J.

1979-12-01

Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

A theoretical perspective on particle acceleration by interplanetary shocks and the Solar Energetic Particle problem

Energy Technology Data Exchange (ETDEWEB)

Verkhoglyadova, Olga P. [Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL35899 (United States); Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA91109 (United States); Zank, Gary P.; Li, Gang [Department of Space Science, UAH, Huntsville, AL35899 (United States); Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL35899 (United States)

2015-02-12

Understanding the physics of Solar Energetic Particle (SEP) events is of importance to the general question of particle energization throughout the cosmos as well as playing a role in the technologically critical impact of space weather on society. The largest, and often most damaging, events are the so-called gradual SEP events, generally associated with shock waves driven by coronal mass ejections (CMEs). We review the current state of knowledge about particle acceleration at evolving interplanetary shocks with application to SEP events that occur in the inner heliosphere. Starting with a brief outline of recent theoretical progress in the field, we focus on current observational evidence that challenges conventional models of SEP events, including complex particle energy spectra, the blurring of the distinction between gradual and impulsive events, and the difference inherent in particle acceleration at quasi-parallel and quasi-perpendicular shocks. We also review the important problem of the seed particle population and its injection into particle acceleration at a shock. We begin by discussing the properties and characteristics of non-relativistic interplanetary shocks, from their formation close to the Sun to subsequent evolution through the inner heliosphere. The association of gradual SEP events with shocks is discussed. Several approaches to the energization of particles have been proposed, including shock drift acceleration, diffusive shock acceleration (DSA), acceleration by large-scale compression regions, acceleration by random velocity fluctuations (sometimes known as the “pump mechanism”), and others. We review these various mechanisms briefly and focus on the DSA mechanism. Much of our emphasis will be on our current understanding of the parallel and perpendicular diffusion coefficients for energetic particles and models of plasma turbulence in the vicinity of the shock. Because of its importance both to the DSA mechanism itself and to the

Software tools for the particle accelerator designs

International Nuclear Information System (INIS)

Sugimoto, Masayoshi

1988-01-01

The software tools used for the designs of the particle accelerators are going to be implemented on the small computer systems, such as the personal computers or the work stations. These are called from the interactive environment like a window application program. The environment contains the small expert system to make easy to select the design parameters. (author)

Particle accelerator physics

CERN Document Server

Wiedemann, Helmut

2015-01-01

This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...

Radiation safety aspects of high energy particle accelerators

International Nuclear Information System (INIS)

Subbaiah, K.V.

2007-01-01

High-energy accelerators are widely used for various applications in industry, medicine and research. These accelerators are capable of accelerating both ions and electrons over a wide range of energy and subsequently are made to impinge on the target materials. Apart from generating intended reactions in the target, these projectiles can also generate highly penetrating radiations such as gamma rays and neutrons. Over exposure to these radiations will cause deleterious effects on the living beings. Various steps taken to protect workers and general public from these harmful radiations is called radiation safety. The primary objective in establishing permissible values for occupational workers is to keep the radiation worker well below a level at which adverse effects are likely to be observed during one's life time. Another objective is to minimize the incidence of genetic effects for the population as a whole. Today's presentation on radiation safety of accelerators will touch up on the following sub-topics: Types of particle accelerators and their applications; AERB directives on dose limits; Radiation Source term of accelerators; Shielding Design-Use of Transmission curves and Tenth Value layers; Challenges for accelerator health physicists

Detecting chaos in particle accelerators through the frequency map analysis method.

Science.gov (United States)

Papaphilippou, Yannis

2014-06-01

The motion of beams in particle accelerators is dominated by a plethora of non-linear effects, which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of different particle accelerator categories, the theory of non-linear particle motion is outlined. The recent developments on the methods employed for the analysis of chaotic beam motion are detailed. In particular, the ability of the frequency map analysis method to detect chaotic motion and guide the correction of non-linear effects is demonstrated in particle tracking simulations but also experimental data.

Laser-driven particle acceleration towards radiobiology and medicine

CERN Document Server

2016-01-01

This book deals with the new method of laser-driven acceleration for application to radiation biophysics and medicine. It provides multidisciplinary contributions from world leading scientist in order to assess the state of the art of innovative tools for radiation biology research and medical applications of ionizing radiation. The book contains insightful contributions on highly topical aspects of spatio-temporal radiation biophysics, evolving over several orders of magnitude, typically from femtosecond and sub-micrometer scales. Particular attention is devoted to the emerging technology of laser-driven particle accelerators and their applicatio to spatio-temporal radiation biology and medical physics, customization of non-conventional and selective radiotherapy and optimized radioprotection protocols.

Novel applications of particle accelerators to radiotherapy

International Nuclear Information System (INIS)

Kreiner, A.J.; Burlon, A.A.; Universidad Nacional de San Martin, Villa Ballester

2002-01-01

Charged hadrons (protons and heavier ions) have very definite advantages over photons as far as radiotherapy applications are concerned. They allow for much better spatial dose localization due to their charge, relatively high mass and nature of the energy deposition process. In the frame of an attempt to promote the introduction of hadrontherapy in Argentina an external beam facility has been installed at our tandem accelerator TANDAR. The advantages of heavy ions can only be fully exploited for tumors of well defined localization. In certain types of malignancies, however, the region infiltrated by tumor cells is diffuse, with no sharp boundaries and with microscopic ramifications. In such cases (particularly in certain brain cancers) a more sophisticated scheme has been suggested called boron neutron capture therapy (BNCT). In this work, the use of the Tandar accelerator to produce neutrons for feasibility studies for BNCT through low-energy proton beams on a thick LiF target is being briefly described. Studies on the 13 C(d,n) reaction and a comparison with other neutron-producing reactions are also mentioned. Simulation work to optimize an accelerator-based neutron production target is discussed. A project is being prepared to develop a small proton accelerator in Argentina. Technical specifications of this machine are briefly discussed. (author)

Innovative Digitally Controlled Particle Accelerator Magnet Power Supply

DEFF Research Database (Denmark)

Nielsen, Rasmus Ørndrup; Bidoggia, Benoit; Maheshwari, Ram Krishan

2013-01-01

Particle accelerator magnet power supplies needs to be extremely precise. A new and innovative power supply for particle accelerator magnets is proposed. The topologies for the input and the output converter are shown and the control architecture is described.......Particle accelerator magnet power supplies needs to be extremely precise. A new and innovative power supply for particle accelerator magnets is proposed. The topologies for the input and the output converter are shown and the control architecture is described....

The acceleration of particles at propagating interplanetary shocks

Science.gov (United States)

Prinsloo, P. L.; Strauss, R. D. T.

2017-12-01

Enhancements of charged energetic particles are often observed at Earth following the eruption of coronal mass ejections (CMEs) on the Sun. These enhancements are thought to arise from the acceleration of those particles at interplanetary shocks forming ahead of CMEs, propagating into the heliosphere. In this study, we model the acceleration of these energetic particles by solving a set of stochastic differential equations formulated to describe their transport and including the effects of diffusive shock acceleration. The study focuses on how acceleration at halo-CME-driven shocks alter the energy spectra of non-thermal particles, while illustrating how this acceleration process depends on various shock and transport parameters. We finally attempt to establish the relative contributions of different seed populations of energetic particles in the inner heliosphere to observed intensities during selected acceleration events.

Particle acceleration at shocks in the inner heliosphere

Science.gov (United States)

Parker, Linda Neergaard

This dissertation describes a study of particle acceleration at shocks via the diffusive shock acceleration mechanism. Results for particle acceleration at both quasi-parallel and quasi-perpendicular shocks are presented to address the question of whether there are sufficient particles in the solar wind thermal core, modeled as either a Maxwellian or kappa- distribution, to account for the observed accelerated spectrum. Results of accelerating the theoretical upstream distribution are compared to energetic observations at 1 AU. It is shown that the particle distribution in the solar wind thermal core is sufficient to explain the accelerated particle spectrum downstream of the shock, although the shape of the downstream distribution in some cases does not follow completely the theory of diffusive shock acceleration, indicating possible additional processes at work in the shock for these cases. Results show good to excellent agreement between the theoretical and observed spectral index for one third to one half of both quasi-parallel and quasi-perpendicular shocks studied herein. Coronal mass ejections occurring during periods of high solar activity surrounding solar maximum can produce shocks in excess of 3-8 shocks per day. During solar minimum, diffusive shock acceleration at shocks can generally be understood on the basis of single independent shocks and no other shock necessarily influences the diffusive shock acceleration mechanism. In this sense, diffusive shock acceleration during solar minimum may be regarded as Markovian. By contrast, diffusive shock acceleration of particles at periods of high solar activity (e.g. solar maximum) see frequent, closely spaced shocks that include the effects of particle acceleration at preceding and following shocks. Therefore, diffusive shock acceleration of particles at solar maximum cannot be modeled on the basis of diffusive shock acceleration as a single, independent shock and the process is essentially non-Markovian. A

Characterization Study of Accelerator for Application in Biotechnology

International Nuclear Information System (INIS)

Yazid-M; Muryono, H.

2000-01-01

The characterization of accelerator for application in biotechnology was studied. Accelerator is a machine to produce ion beam particles. Accelerator can be used for biotechnology experiments. Ion beam particles irradiation on the biological material will produced variabilities of genetics and induced mutations. In general, new varieties were found by hybridization method or mutation breeding method by gamma rays irradiation. Ion beam particles can be used for biological material irradiation to find variabilities of genetics and induced mutations. The high percentage of mutation rate and LET value by ion beam particles irradiation was found higher than by gamma rays irradiation. Ion beam particle irradiation can also be controlled and foewed to target in biological material. The characterization of accelerator needed for biotechnology experiments are types of accelerator (Tandem Van de Graff, AVF Cyclotron, Synchrotron, Rilac), types of ion particles (C, He, electron, Ar, Ne, Ni, Al, Xe and Au), range of energy (5 - 2.090 MeV), range of dose irradiation (10 - 250 Gy), range of ion current (0.02 - 20 nA), range of ion beam particles diameter (10 - 100 μm), range of LET value (300 - 1.800 keV/μm ) and irradiation time (5 - 30 seconds/samples). (author)

Acceleration of particles in plasmas

CERN Multimedia

CERN. Geneva

2007-01-01

The accelerating fields in radio-frequency accelerators are limited to roughly 100 MV/m due to material breakdown which occurs on the walls of the structure. In contrast, a plasma, being already ionized, can support electric fields in excess of 100 GV/m. Such high accelerating gradients hold the promise of compact particle accelerators. Plasma acceleration has been an emerging and fast growing field of research in the past two decades. In this series of lectures, we will review the principles of plasma acceleration. We will see how relativistic plasma waves can be excited using an ultra-intense laser or using a particle beam. We will see how these plasma waves can be used to accelerate electrons to high energy in short distances. Throughout the lectures, we will also review recent experimental results. Current laser-plasma experiments throughout the world have shown that monoenergetic electron beams from 100 MeV to 1 GeV can be obtained in distances ranging from the millimetre to the centimetre. Experiments a...

Control system technology for particle accelerators

International Nuclear Information System (INIS)

Tsumura, Yoshihiko; Matsuo, Keiichi; Maruyama, Takayuki.

1995-01-01

Control systems for particle accelerators are being designed around open-architecture systems, which allows easy upgrading, high-speed networks and high-speed processors. Mitsubishi Electric is applying realtime Unix operating systems, fiber-distributed data interface (FDDI), shared memory networks and remote I/O systems to achieve these objectives. In the area of vacuum control systems, which requires large-scale sequence control, the corporation is employing general-purpose programmable logic controllers (PLCs) to achieve cost-effective design. Software for these applications is designed around a library of application program interfaces (APIs) that give users direct access to key system functions. (author)

Applications of proton and deuteron accelerators

Energy Technology Data Exchange (ETDEWEB)

Todd, A.M.M. (Grumman Corporate Research Center, Princeton, NJ (United States))

1993-06-01

Applications of positive and negative hydrogen and deuterium ion accelerators beyond basic research are increasing. Large scale proposed national laboratory/industrial projects include the Accelerator Production of Tritium (APT) which will utilize protons, and the International Fusion Material Irradiation Facility (IFMIF) which will accelerate a deuteron beam into a lithium target. At the small scale end, radio-frequency quadrupole (RFQ) accelerator based systems have been built for neutron activation analysis and for applications such as explosive detection. At an intermediate scale, the Loma Linda proton therapy accelerator is now successfully treating a full schedule of patients, and more than half a dozen such hospital based units are under active study world-wide. At this same scale, there are also several ongoing negative ion, military accelerator projects which include the Continuous Wave Deuterium Demonstrator (CWDD) and the Neutral Particle Beam Space Experiment (NPBSE). These respective deuterium and hydrogen accelerators, which have not been previously described, are the focus of this paper. (orig.)

New techniques for particle accelerators

International Nuclear Information System (INIS)

Sessler, A.M.

1990-06-01

A review is presented of the new techniques which have been proposed for use in particle accelerators. Attention is focused upon those areas where significant progress has been made in the last two years--in particular, upon two-beam accelerators, wakefield accelerators, and plasma focusers. 26 refs., 5 figs., 1 tab

Particle accelerators and scientific culture

International Nuclear Information System (INIS)

Amaldi, U.

1979-01-01

A historical review of fifty years of physics around particle accelerators, from the first nuclear reactions produced by beams of artificially accelerated particles to the large multinational projects now under discussion. The aim is to show how the description of natural phenomena has been shaped by advances in theoretical understanding, the development of new techniques, and the characters of men. Large use has been made of quotations from many of the scientists involved. (Auth.)

Particle accelerators and scientific culture

International Nuclear Information System (INIS)

Amaldi, U.

1979-01-01

A historical review of fifty years of physics around particle accelerators, from the first nuclear reactions produced by beams of artificially accelerated particles to the large multinational projects now under discussion. The aim is to show how our description of natural phenomena has been shaped by advances in theoretical understanding, the development of new techniques, and the characters of men. Large use has been made of quotations from many of the scientists involved. (Auth.)

Particle acceleration in near critical density plasma

International Nuclear Information System (INIS)

Gu, Y.J.; Kong, Q.; Kawata, S.; Izumiyama, T.; Nagashima, T.

2013-01-01

Charged particle acceleration schemes driven by ultra intense laser and near critical density plasma interactions are presented. They include electron acceleration in a plasma channel, ion acceleration by the Coulomb explosion and high energy electron beam driven ion acceleration. It is found that under the near critical density plasma both ions and electrons are accelerated with a high acceleration gradient. The electron beam containing a large charge quantity is accelerated well with 23 GeV/cm. The collimated ion bunch reaches 1 GeV. The investigations and discussions are based on 2.5D PIC (particle-in-cell) simulations. (author)

Dynamics and transport of laser-accelerated particle beams

International Nuclear Information System (INIS)

Becker, Stefan

2010-01-01

The subject of this thesis is the investigation and optimization of beam transport elements in the context of the steadily growing field of laser-driven particle acceleration. The first topic is the examination of the free vacuum expansion of an electron beam at high current density. It could be shown that particle tracking codes which are commonly used for the calculation of space charge effects will generate substantial artifacts in the regime considered here. The artifacts occurring hitherto predominantly involve insufficient prerequisites for the Lorentz transformation, the application of inadequate initial conditions and non negligible retardation artifacts. A part of this thesis is dedicated to the development of a calculation approach which uses a more adequate ansatz calculating space charge effects for laser-accelerated electron beams. It can also be used to validate further approaches for the calculation of space charge effects. The next elements considered are miniature magnetic quadrupole devices for the focusing of charged particle beams. General problems involved with their miniaturization concern distorting higher order field components. If these distorting components cannot be controlled, the field of applications is very limited. In this thesis a new method for the characterization and compensation of the distorting components was developed, which might become a standard method when assembling these permanent magnet multipole devices. The newly developed characterization method has been validated at the Mainz Microtron (MAMI) electron accelerator. Now that we can ensure optimum performance, the first application of permanent magnet quadrupole devices in conjunction with laser-accelerated ion beams is presented. The experiment was carried out at the Z-Petawatt laser system at Sandia National Laboratories. A promising application for laser-accelerated electron beams is the FEL in a university-scale size. The first discussion of all relevant aspects

Dynamics and transport of laser-accelerated particle beams

Energy Technology Data Exchange (ETDEWEB)

Becker, Stefan

2010-04-19

The subject of this thesis is the investigation and optimization of beam transport elements in the context of the steadily growing field of laser-driven particle acceleration. The first topic is the examination of the free vacuum expansion of an electron beam at high current density. It could be shown that particle tracking codes which are commonly used for the calculation of space charge effects will generate substantial artifacts in the regime considered here. The artifacts occurring hitherto predominantly involve insufficient prerequisites for the Lorentz transformation, the application of inadequate initial conditions and non negligible retardation artifacts. A part of this thesis is dedicated to the development of a calculation approach which uses a more adequate ansatz calculating space charge effects for laser-accelerated electron beams. It can also be used to validate further approaches for the calculation of space charge effects. The next elements considered are miniature magnetic quadrupole devices for the focusing of charged particle beams. General problems involved with their miniaturization concern distorting higher order field components. If these distorting components cannot be controlled, the field of applications is very limited. In this thesis a new method for the characterization and compensation of the distorting components was developed, which might become a standard method when assembling these permanent magnet multipole devices. The newly developed characterization method has been validated at the Mainz Microtron (MAMI) electron accelerator. Now that we can ensure optimum performance, the first application of permanent magnet quadrupole devices in conjunction with laser-accelerated ion beams is presented. The experiment was carried out at the Z-Petawatt laser system at Sandia National Laboratories. A promising application for laser-accelerated electron beams is the FEL in a university-scale size. The first discussion of all relevant aspects

Effects of Turbulent Magnetic Fields on the Transport and Acceleration of Energetic Charged Particles: Numerical Simulations with Application to Heliospheric Physics

Science.gov (United States)

Guo, Fan

2012-11-01

(kinetic ions and fluid electrons) to investigate the acceleration of low-energy particles (often termed as "injection problem") at parallel shocks. We find that the accelerated particles always gain the first amount of energy by reflection and acceleration at the shock layer. The protons can move off their original field lines in the 3-D electric and magnetic fields. The results are consistent with the acceleration mechanism found in previous 1-D and 2-D simulations. In the second part of Chapter 3, we use a stochastic integration method to study diffusive shock acceleration in the existence of large-scale magnetic variations. We show that the 1-D steady state solution of diffusive shock acceleration can be significantly modified in this situation. The results suggest that the observations of anomalous cosmic rays by Voyager spacecraft can be explained by a 2-D shock that includes the large-scale magnetic field variations. In Chapter 4 we study electron acceleration at a shock passing into a turbulent magnetic field by using a combination of hybrid simulations and test-particle electron simulations. We find that the acceleration of electrons is greatly enhanced by including the effect of large-scale magnetic turbulence. Since the electrons mainly follow along the magnetic lines of force, the large-scale braiding of field lines in space allows the fast-moving electrons interacting with the shock front multiple times. Ripples in the shock front occurring at various scales also contribute to the acceleration by mirroring the electrons. Our calculation shows that this process favors electron acceleration at perpendicular shocks. We discuss the application of this process in interplanetary shocks and flare termination shocks. We also discuss the implication of this study to solar energetic particles (SEPs) by comparing the acceleration of electrons with that of protons. The intensity correlation of electrons and ions in SEP events indicates that perpendicular or quasi

CAS CERN Accelerator School: Applied geodesy for particle accelerators

International Nuclear Information System (INIS)

Turner, S.

1987-01-01

This specialized course addresses the many topics involved in the application of geodesy to large particle accelerators, though many of the techniques described are equally applicable to large construction projects and surveillance systems where the highest possible surveying accuracies are required. The course reflects the considerable experience gained over many years, not only at CERN but in projects all over the world. The methods described range from the latest approach using satellites to recent developments in conventional techniques. They include the global positioning system (GPS), its development, deployment and precision, the use of the Terrameter and the combination or comparison of its results with those of the GPS, the automation of instruments, the management of measurements and data, and the highly evolved treatment of the observations. (orig.)

Particle-in-Cell Codes for plasma-based particle acceleration

CERN Document Server

Pukhov, Alexander

2016-01-01

Basic principles of particle-in-cell (PIC ) codes with the main application for plasma-based acceleration are discussed. The ab initio full electromagnetic relativistic PIC codes provide the most reliable description of plasmas. Their properties are considered in detail. Representing the most fundamental model, the full PIC codes are computationally expensive. The plasma-based acceler- ation is a multi-scale problem with very disparate scales. The smallest scale is the laser or plasma wavelength (from one to hundred microns) and the largest scale is the acceleration distance (from a few centimeters to meters or even kilometers). The Lorentz-boost technique allows to reduce the scale disparity at the costs of complicating the simulations and causing unphysical numerical instabilities in the code. Another possibility is to use the quasi-static approxi- mation where the disparate scales are separated analytically.

Particle acceleration by plasma waves

International Nuclear Information System (INIS)

Joshi, C.

2006-01-01

In an advanced particle accelerator particles are driven near by light velocity through ionized gas. Such plasma devices are compact, cost efficient and usable in many fields. Examples are given in detail. (GL)

Automated detection and analysis of particle beams in laser-plasma accelerator simulations

International Nuclear Information System (INIS)

Ushizima, Daniela Mayumi; Geddes, C.G.; Cormier-Michel, E.; Bethel, E. Wes; Jacobsen, J.; Prabhat; Ruebel, O.; Weber, G.; Hamann, B.

2010-01-01

Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of massive data sets over many time steps using several plots, a routine that is unfeasible for large data collections. Demand for automated analysis is growing along with the volume and size of simulations. Current 2D LWFA simulation datasets are typically between 1GB and 100GB in size, but simulations in 3D are of the order of TBs. The increase in the number of datasets and dataset sizes leads to a need for automatic routines to recognize particle patterns as particle bunches (beam of electrons) for subsequent analysis. Because of the growth in dataset size, the application of machine learning techniques for

Particle accelerators in the Czech lands

International Nuclear Information System (INIS)

Janovsky, I.

2007-01-01

The paper is structured as follows: A short look into history of accelerators; Particle accelerators in the Czech lands (Accelerators at the Institute of Nuclear Physics; Accelerators at the Faculty of Mathematics and Physics, Charles University; Czechoslovak betatron, accelerators for non-destructive testing and radiotherapy; Czechoslovak high-frequency linear electron accelerator; Czechoslovak-Soviet microtron; Accelerators at the State Research Institute of Textiles; Accelerators at the Kablo Vrchlabi plant; and Cyclotrons in the medical sector. (P.A.)

Particle accelerator; the Universe machine

CERN Multimedia

Yurkewicz, Katie

2008-01-01

"In summer 2008, scientists will switch on one of the largest machines in the world to search for the smallest of particle. CERN's Large Hadron Collider particle accelerator has the potential to chagne our understanding of the Universe."

Workshop on the accelerator for particle therapy

International Nuclear Information System (INIS)

Inoue, M.; Ujeno, Y.

1991-02-01

A two-day workshop on the accelerator for particle therapy was held on August 22-23, 1990, with the aim of mutual understanding of medical accelerators among investigators. The state-of-the-art facilities in Japan and medical proton accelerators in Japan and other countries were introduced. This is a compilation of papers presented at the workshop: (1) particle radiotherapy at the National Institute of Radiological Sciences (NIRS); (2) proton therapy; (3) treatment planning, especially for photon and electron therapies; (4) heavy ion synchrotron project at the NIRS; (5) medical proton accelerator project of Tsukuba University and recent status of Loma Linda University Medical Center Proton Beam Facility; (6) inspection report on the Loma Linda University Medical Center Proton Beam Facility; (7) accelerator project of Kyoto University; (8) actual conditions of the 7 MeV proton linear accelerator; (9) design study of superconducting compact cyclotron prototype model; (10) medical superconducting prototype cyclotron; (11) RCNP cyclotron cascade project; (12) beam extraction from synchrotron; (13) radiation safety design in high energy particle accelerator facilities. (N.K.)

Relevance of plasma science to particle accelerators

International Nuclear Information System (INIS)

Herrmannsfeldt, W.B.

1998-01-01

In following the theme of this Symposium, ''Plasma Science and Its Applications,'' the authors may be suggesting to some readers that the other applications of Plasma Science somehow justify the existence of a field traditionally devoted to fusion energy. In fact, they do not believe that plasma science can or should be justified for its spin-off contributions. Nevertheless, the unity of science would be seriously threatened by a precipitous decline in the support for plasma science. It is that unity which repeatedly has been verified as one looks for how advances in one field are crucial to several other seemingly fundamentally different fields. Thus it is in this case, as a representative of the community of Particle Accelerator Scientists, that they show four significant areas in which the methods and the results of plasma science have been applied to Accelerator Science. They have deliberately skipped plasma ion sources which are perhaps the most obvious application of plasmas to accelerators. Two of their four examples are cases in which the computational methods of plasma science have been adopted, and two are examples in which the plasmas themselves are employed. One of each category are now actively in use and the other one in each category is being used to develop or design new devices

A reflexing electron microwave amplifier for rf particle accelerator applications

International Nuclear Information System (INIS)

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

1988-01-01

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

Public Lecture | Philipe Lebrun | "Particle accelerators" | 2 September

CERN Multimedia

2014-01-01

"Les accélérateurs de particules : vecteurs de découvertes, moteurs de développement", by Dr. Philippe Lebrun.   2 September 2014 - 7:30 p.m. Globe of Science and Innovation Particle accelerators have been used in fundamental research for over a century, allowing physicists to discover elementary particles and study them at increasingly smaller scales. Making use of emerging technologies whose progress they helped to stimulate, they developed exponentially throughout the 20th century to become major tools for research today, not only in particle physics but also – as powerful radiation sources for probing matter – in atomic and molecular physics, condensed matter physics and materials science. They have also found applications in society, where they are increasingly used in a wide range of fields including applied sciences, medicine (research and clinical applications) and industry. The lecture will cover examples ...

Charged particle accelerator

Energy Technology Data Exchange (ETDEWEB)

Ress, T I; Nolde, G V

1974-11-25

A charged particle accelerator is described. It is made of an enclosure arranged for channeling a stream of charged particles along a predetermined path, and propelling means juxtaposed to the enclosure for generating a magnetic field moving in a predetermined direction with respect to each point of the path, the magnetic flux vector of that field being transverse to that path at every point, which gives the particles, along said path, a velocity connected to that of the mobile field by a predetermined relation. This can be applied to the fast production of chemical compounds, to the emission of neutrons and of thermal energy, and to the production of mechanical energy for propelling space ships.

Charged particle accelerator

International Nuclear Information System (INIS)

Ress, T.I.; Nolde, G.V.

1974-01-01

A charged particle accelerator is described. It is made of an enclosure arranged for channeling a stream of charged particles along a predetermined path, and propelling means juxtaposed to said enclosure for generating therein a magnetic field moving in a predetermined direction with respect to each point of said path, the magnetic flux vector of that field being transverse to that path at every point, which gives the particles, along said path, a velocity connected to that of the mobile field by a predetermined relation. This can be applied to the fast production of chemical compounds, to the emission of neutrons and of thermal energy, and to the production of mechanical energy for propelling space ships [fr

Medical applications of accelerators

CERN Document Server

Rossi, Sandro

1998-01-01

At Present, about five thousands accelerators are devoted to biomedical applications. They are mainly used in radiotherapy, research and medical radioisotopes production. In this framework oncological hadron-therapy deserves particular attention since it represents a field in rapid evolution thanks to the joint efforts of laboratories with long experiences in particle physics. It is the case of CERN where the design of an optimised synchrotron for medical applications has been pursued. These lectures present these activities with particular attention to the new developments which are scientifically interesting and/or economically promising.

CERN Accelerator School: Intensity Limitations in Particle Beams | 2-11 November

CERN Multimedia

2015-01-01

Registration is now open for the CERN Accelerator School’s specialised course on Intensity Limitations in Particle Beams, to be held at CERN between 2 and 11 November 2015.   This course will mainly be of interest to staff in accelerator laboratories, university departments and companies manufacturing accelerator equipment. Many accelerators and storage rings, whether intended for particle physics experiments, synchrotron light sources or industrial applications, require beams of high brightness and the highest possible intensities. A good understanding of the possible limitations is required to achieve the desired performance. The programme for this course will cover the interaction of beams with their surroundings, with other beams and further collective effects. Lectures on the effects and possible mitigations will be complemented by tutorials. Further information can be found at: http://cas.web.cern.ch/cas/Intensity-Limitations-2015/IL-advert.html   http:/...

Turbulence and particle acceleration

International Nuclear Information System (INIS)

Scott, J.S.

1975-01-01

A model for the production of high energy particles in the supernova remnant Cas A is considered. The ordered expansion of the fast moving knots produce turbulent cells in the ambient interstellar medium. The turbulent cells act as magnetic scattering centers and charged particles are accelerated to large energies by the second order Fermi mechanism. Model predictions are shown to be consistent with the observed shape and time dependence of the radio spectrum, and with the scale size of magnetic field irregularities. Assuming a galactic supernova rate at 1/50 yr -1 , this mechanism is capable of producing the observed galactic cosmic ray flux and spectrum below 10 16 eV/nucleon. Several observed features of galactic cosmic rays are shown to be consistent with model predictions. A model for the objects known as radio tall galaxies is also presented. Independent blobs of magnetized plasma emerging from an active radio galaxy into an intracluster medium become turbulent due to Rayleigh--Taylor and Kelvin--Helmholz instabilities. The turbulence produces both in situ betatron and 2nd order Fermi accelerations. Predictions of the dependence of spectral index and flux on distance along the tail match observations well. Fitting provides values of physical parameters in the blobs. The relevance of this method of particle acceleration for the problem of the origin of x-ray emission in clusters of galaxies is discussed

Dynamics of particles accelerated by head-on collisions of two magnetized plasma shocks

Science.gov (United States)

Takeuchi, Satoshi

2018-02-01

A kinetic model of the head-on collision of two magnetized plasma shocks is analyzed theoretically and in numerical calculations. When two plasmas with anti-parallel magnetic fields collide, they generate magnetic reconnection and form a motional electric field at the front of the collision region. This field accelerates the particles sandwiched between both shock fronts to extremely high energy. As they accelerate, the particles are bent by the transverse magnetic field crossing the magnetic neutral sheet, and their energy gains are reduced. In the numerical calculations, the dynamics of many test particles were modeled through the relativistic equations of motion. The attainable energy gain was obtained by multiplying three parameters: the propagation speed of the shock, the magnitude of the magnetic field, and the acceleration time of the test particle. This mechanism for generating high-energy particles is applicable over a wide range of spatial scales, from laboratory to interstellar plasmas.

Safety in design and operation of low energy particle accelerators

International Nuclear Information System (INIS)

Badawy, I.

1991-01-01

This paper studies the safety in design and operation of low energy accelerators which produce beams of accelerated charged particles and radiations. As radiation sources, the accelerators are widely used in scientific research, industry, food and medical applications. The risks to human and environment are considered. The safety in accelerators is discussed-particularly-the shielding against ionizing radiations, overexposure to RF radiation fire hazards and power failures. Also the paper studies the emergency response at incidents. Emergency procedures are recommended for each type of emergency. Reporting to the competent Authority is also recommended to be prepared for each incident. The basic principles of regulatory control, licensing and inspections for accelerator facilities are discussed. The relation with the competent authority is pointed out. 4 fig

Machine protection: availability for particle accelerators

International Nuclear Information System (INIS)

Apollonio, A.

2015-01-01

Machine availability is a key indicator for the performance of the next generation of particle accelerators. Availability requirements need to be carefully considered during the design phase to achieve challenging objectives in different fields, as e.g. particle physics and material science. For existing and future High-Power facilities, such as ESS (European Spallation Source) and HL-LHC (High-Luminosity LHC), operation with unprecedented beam power requires highly dependable Machine Protection Systems (MPS) to avoid any damage-induced downtime. Due to the high complexity of accelerator systems, finding the optimal balance between equipment safety and accelerator availability is challenging. The MPS architecture, as well as the choice of electronic components, have a large influence on the achievable level of availability. In this thesis novel methods to address the availability of accelerators and their protection systems are presented. Examples of studies related to dependable MPS architectures are given in the thesis, both for Linear accelerators (Linac4, ESS) and circular particle colliders (LHC and HL-LHC). A study of suitable architectures for interlock systems of future availability-critical facilities is presented. Different methods have been applied to assess the anticipated levels of accelerator availability. The thesis presents the prediction of the performance (integrated luminosity for a particle collider) of LHC and future LHC up- grades, based on a Monte Carlo model that allows reproducing a realistic timeline of LHC operation. This model does not only account for the contribution of MPS, but extends to all systems relevant for LHC operation. Results are extrapolated to LHC run 2, run 3 and HL-LHC to derive individual system requirements, based on the target integrated luminosity. (author)

Charged particle accelerator

International Nuclear Information System (INIS)

Arakawa, Kazuo.

1969-01-01

An accelerator is disclosed having a device which permits the electrodes of an accelerator tube to be readily conditioned in an uncomplicated manner before commencing operation. In particle accelerators, it is necessary to condition the accelerator electrodes before a stable high voltage can be applied. Large current accelerators of the cockcroft-walton type require a complicated manual operation which entails applying to the electrodes a low voltage which is gradually increased to induce a vacuum discharge and then terminated. When the discharge attains an extremely low level, the voltage is again impressed and again raised to a high value in low current type accelerators, a high voltage power supply charges the electrodes once to induce discharge followed by reapplying the voltage when the vacuum discharge reaches a low level, according to which high voltage is automatically applied. This procedure, however, requires that the high voltage power supply be provided with a large internal resistance to limit the current to within several milliamps. The present invention connects a high voltage power supply and an accelerator tube through a discharge current limiting resistor wired in parallel with a switch. Initially, the switch is opened enabling the power supply to impress a voltage limited to a prescribed value by a suitably chosen resistor. Conditioning is effected by allowing the voltage between electrodes to increase and is followed by closing the switch through which high voltage is applied directly to the accelerator for operation. (K.J. Owens)

Proceedings of a workshop on Applications of Accelerators

International Nuclear Information System (INIS)

Herrmannsfeldt, W.B.; Sessler, A.M.; Alonso, J.R.

1994-01-01

This document is a compilation of material collected as the results of a workshop, Applications of Accelerators, held at the Stanford Linear Accelerator Center, 1--2 December 1993. The material collected here has been edited for style and to minimize duplication. Footnotes will identify the original source of the material. We believe that the reader will find that this document has something for every interest. There are applications in the fields of health, food preservation, energy, environmental monitoring and protection, and industrial processing. Man y of the examples discussed have already passed the demonstration stage. Most of the others are the subject of active accelerator research. Taken as a whole, the particle accelerator field contains a wealth of application opportunities, some already in use, and many more ready to be exploited

Lasers and new methods of particle acceleration

International Nuclear Information System (INIS)

Parsa, Z.

1998-02-01

There has been a great progress in development of high power laser technology. Harnessing their potential for particle accelerators is a challenge and of great interest for development of future high energy colliders. The author discusses some of the advances and new methods of acceleration including plasma-based accelerators. The exponential increase in sophistication and power of all aspects of accelerator development and operation that has been demonstrated has been remarkable. This success has been driven by the inherent interest to gain new and deeper understanding of the universe around us. With the limitations of the conventional technology it may not be possible to meet the requirements of the future accelerators with demands for higher and higher energies and luminosities. It is believed that using the existing technology one can build a linear collider with about 1 TeV center of mass energy. However, it would be very difficult (or impossible) to build linear colliders with energies much above one or two TeV without a new method of acceleration. Laser driven high gradient accelerators are becoming more realistic and is expected to provide an alternative, (more compact, and more economical), to conventional accelerators in the future. The author discusses some of the new methods of particle acceleration, including laser and particle beam driven plasma based accelerators, near and far field accelerators. He also discusses the enhanced IFEL (Inverse Free Electron Laser) and NAIBEA (Nonlinear Amplification of Inverse-Beamstrahlung Electron Acceleration) schemes, laser driven photo-injector and the high energy physics requirements

A New Paradigm for Flare Particle Acceleration

Science.gov (United States)

Guidoni, Silvina E.; Karpen, Judith T.; DeVore, C. Richard

2017-08-01

The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission and its spectra in solar flares is not well understood. Here, we propose a first-principle-based model of particle acceleration that produces energy spectra that closely resemble those derived from hard X-ray observations. Our mechanism uses contracting magnetic islands formed during fast reconnection in solar flares to accelerate electrons, as first proposed by Drake et al. (2006) for kinetic-scale plasmoids. We apply these ideas to MHD-scale islands formed during fast reconnection in a simulated eruptive flare. A simple analytic model based on the particles’ adiabatic invariants is used to calculate the energy gain of particles orbiting field lines in our ultrahigh-resolution, 2.5D, MHD numerical simulation of a solar eruption (flare + coronal mass ejection). Then, we analytically model electrons visiting multiple contracting islands to account for the observed high-energy flare emission. Our acceleration mechanism inherently produces sporadic emission because island formation is intermittent. Moreover, a large number of particles could be accelerated in each macroscopic island, which may explain the inferred rates of energetic-electron production in flares. We conclude that island contraction in the flare current sheet is a promising candidate for electron acceleration in solar eruptions. This work was supported in part by the NASA LWS and H-SR programs..

Single particle dynamics in circular accelerators

International Nuclear Information System (INIS)

Ruth, R.D.

1986-10-01

The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)

Nested high voltage generator/particle accelerator

International Nuclear Information System (INIS)

Adler, R.J.

1992-01-01

This patent describes a modular high voltage particle accelerator having an emission axis and an emission end, the accelerator. It comprises: a plurality of high voltage generators in nested adjacency to form a nested stack, each the generator comprising a cup-like housing having a base and a tubular sleeve extending from the base, a primary transformer winding encircling the nested stack; a secondary transformer winding between each adjacent pair of housings, magnetically linked to the primary transformer winding through the gaps; a power supply respective to each of the secondary windings converting alternating voltage from its respective secondary winding to d.c. voltage, the housings at the emission end forming a hollow throat for particle acceleration, a vacuum seal at the emission end of the throat which enables the throat to be evacuated; a particle source in the thrond power means to energize the primary transformer winding

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data

International Nuclear Information System (INIS)

Rubel, Oliver; Prabhat, Mr.; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

2008-01-01

Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset

US PARTICLE ACCELERATOR SCHOOL: Summer schools

Energy Technology Data Exchange (ETDEWEB)

Anon.

1989-11-15

Continuing it's educational efforts, the US Particle Accelerator School (USPAS) held two summer schools this year. The USPAS has two basic purposes — education in accelerator physics and technology, in particular to train apprentices and update experts; and to encourage US universities and Laboratories to offer programmes in accelerator physics by developing textbooks, training faculty, and organizing schools.

Algorithms for tracking of charged particles in circular accelerators

International Nuclear Information System (INIS)

Iselin, F.Ch.

1986-01-01

An important problem in accelerator design is the determination of the largest stable betatron amplitude. This stability limit is also known as the dynamic aperture. The equations describing the particle motion are non-linear, and the Linear Lattice Functions cannot be used to compute the stability limits. The stability limits are therefore usually searched for by particle tracking. One selects a set of particles with different betatron amplitudes and tracks them for many turns around the machine. The particles which survive a sufficient number of turns are termed stable. This paper concentrates on conservative systems. For this case the particle motion can be described by a Hamiltonian, i.e. tracking particles means application of canonical transformations. Canonical transformations are equivalent to symplectic mappings, which implies that there exist invariants. These invariants should not be destroyed in tracking

Canonical harmonic tracking of charged particles in circular accelerators

International Nuclear Information System (INIS)

Kvardakov, V.; Levichev, E.

2006-01-01

Harmonic tracking is a method used to study non-linear particle dynamics in a circular accelerator. The tracking algorithm is based on numerical solution of the Hamilton equations of motion. An essential feature of the method is the approximation of Hamiltonian perturbation terms by a finite number of azimuthal harmonics, which provides an effective tool for optimization of non-linear particle motion. The equations of motion are solved canonically, with the first-order prediction made using the explicit Lie transformation. The major features of harmonic tracking are presented and examples of its application are discussed

Canonical harmonic tracking of charged particles in circular accelerators

Science.gov (United States)

Kvardakov, V.; Levichev, E.

2006-03-01

Harmonic tracking is a method used to study non-linear particle dynamics in a circular accelerator. The tracking algorithm is based on numerical solution of the Hamilton equations of motion. An essential feature of the method is the approximation of Hamiltonian perturbation terms by a finite number of azimuthal harmonics, which provides an effective tool for optimization of non-linear particle motion. The equations of motion are solved canonically, with the first-order prediction made using the explicit Lie transformation. The major features of harmonic tracking are presented and examples of its application are discussed.

Fast risetime BLT switches for accelerators applications

International Nuclear Information System (INIS)

Kirkman-Amemiya, G.; Reinhardt, N.; Choi, M.S.; Gundersen, M.A.

1991-01-01

Several particle accelerator systems require repetitive switches capable to switching peak currents of several kA with short risetimes, in particular kicker magnets used to transfer particle beams from one section of an accelerator to another require current pulses that rise from zero to 100% in a time determined by the separation between particle bunches which can be only 10's of nsec in some applications. One particular application is the injection and extraction kickers for the low energy booster (LEB) of the superconducting super collider (SSC) which requires < 50nsec 0-99% risetime. Another system with similarly strict risetime requirement is the kicker for the Stanford Linear Collider electron damping rings. In this work, a fast risetime BLT switch which has demonstrated 17kA at 30kV with < 60nsec risetime, 1.5kA at 20kV with < 18nsec risetime, and up to 240Hz operation at 20kV, 7kA is reported. A tetrode triggering method is described which reduces risetime by eliminating prepulse behavior

From particle physics to medical applications

CERN Document Server

Dosanjh, Manjit

2017-01-01

CERN is the world's largest particle physics research laboratory. Since it was established in 1954, it has made an outstanding contribution to our understanding of the fundamental particles and their interactions, and also to the technologies needed to analyse their properties and behaviour. The experimental challenges have pushed the performance of particle accelerators and detectors to the limits of our technical capabilities, and these groundbreaking technologies can also have a significant impact in applications beyond particle physics. In particular, the detectors developed for particle physics have led to improved techniques for medical imaging, while accelerator technologies lie at the heart of the irradiation methods that are widely used for treating cancer. Indeed, many important diagnostic and therapeutic techniques used by healthcare professionals are based either on basic physics principles or the technologies developed to carry out physics research. Ever since the discovery of x-rays by Roentgen...

US PARTICLE ACCELERATOR SCHOOL: Summer schools

International Nuclear Information System (INIS)

Anon.

1989-01-01

Continuing it's educational efforts, the US Particle Accelerator School (USPAS) held two summer schools this year. The USPAS has two basic purposes — education in accelerator physics and technology, in particular to train apprentices and update experts; and to encourage US universities and Laboratories to offer programmes in accelerator physics by developing textbooks, training faculty, and organizing schools

Neural Networks for Modeling and Control of Particle Accelerators

Science.gov (United States)

Edelen, A. L.; Biedron, S. G.; Chase, B. E.; Edstrom, D.; Milton, S. V.; Stabile, P.

2016-04-01

Particle accelerators are host to myriad nonlinear and complex physical phenomena. They often involve a multitude of interacting systems, are subject to tight performance demands, and should be able to run for extended periods of time with minimal interruptions. Often times, traditional control techniques cannot fully meet these requirements. One promising avenue is to introduce machine learning and sophisticated control techniques inspired by artificial intelligence, particularly in light of recent theoretical and practical advances in these fields. Within machine learning and artificial intelligence, neural networks are particularly well-suited to modeling, control, and diagnostic analysis of complex, nonlinear, and time-varying systems, as well as systems with large parameter spaces. Consequently, the use of neural network-based modeling and control techniques could be of significant benefit to particle accelerators. For the same reasons, particle accelerators are also ideal test-beds for these techniques. Many early attempts to apply neural networks to particle accelerators yielded mixed results due to the relative immaturity of the technology for such tasks. The purpose of this paper is to re-introduce neural networks to the particle accelerator community and report on some work in neural network control that is being conducted as part of a dedicated collaboration between Fermilab and Colorado State University (CSU). We describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.

Double layers are not particle accelerators

International Nuclear Information System (INIS)

Bryant, D.A.; Bingham, R.; Angelis, U. de.

1991-02-01

It is pointed out that the continuing advocacy of electrostatic double layers as particle accelerators in the aurora and other space and astrophysical plasmas is fundamentally unsound. It is suggested furthermore that there is little reason to invoke static or quasi-static electric fields as the cause of auroral electron acceleration. Stochastic acceleration by electrostatic wave turbulence appears to present a natural explanation for this and for electron acceleration in other space and astrophysical plasmas. (author)

Pulsed power accelerators for particle beam fusion

International Nuclear Information System (INIS)

Martin, T.H.; Barr, G.W.; VanDevender, J.P.; White, R.A.; Johnson, D.L.

1980-01-01

Sandia National Laboratories is completing the construction phase of the Particle Beam Fusion Accelerator-I (PBFA-I). Testing of the 36 module, 30 TW, 1 MJ output accelerator is in the initial stages. The 4 MJ, PBFA Marx generator has provided 3.6 MA into water-copper sulfate load resistors with a spread from first to last Marx firing between 15 to 25 ns and an output power of 5.7 TW. This accelerator is a modular, lower voltage, pulsed power device that is capable of scaling to power levels exceeding 100 TW. The elements of the PBFA technology and their integration into an accelerator system for particle beam fusion will be discussed

High intensity accelerator for a wide range of applications

International Nuclear Information System (INIS)

Conard, E.M.

1994-01-01

When looking at commercial applications of accelerators from a market point of view, it appears that a common accelerator design could meet different users' needs. This would benefit both the manufacturer and the user by multiplying the number of machines sold, thus lowering their cost and improving their quality. These applications include: radioisotope production for medical imaging (positron emission tomography), industrial imaging and non-destructive testing (e.g. neutron radiography, explosive and drug detection in luggage or freight). This paper investigates the needs of the various applications and defines their common denominator to establish suitable specifications (type of particles, energy, intensity). Different accelerator types (cyclotrons, linear accelerators and electrostatic machines) are reviewed and compared on performance and estimated costs. A high intensity tandem accelerator design is studied in more detail as it seems the most appropriate candidate. ((orig.))

Machine Protection: Availability for Particle Accelerators

CERN Document Server

Apollonio, Andrea; Schmidt, Ruediger

2015-03-16

Machine availability is a key indicator for the performance of the next generation of particle accelerators. Availability requirements need to be carefully considered during the design phase to achieve challenging objectives in different fields, as e.g. particle physics and material science. For existing and future High-Power facilities, such as ESS (European Spallation Source) and HL-LHC (High-Luminosity LHC), operation with unprecedented beam power requires highly dependable Machine Protection Systems (MPS) to avoid any damage-induced downtime. Due to the high complexity of accelerator systems, finding the optimal balance between equipment safety and accelerator availability is challenging. The MPS architecture, as well as the choice of electronic components, have a large influence on the achievable level of availability. In this thesis novel methods to address the availability of accelerators and their protection systems are presented. Examples of studies related to dependable MPS architectures are given i...

Radiation therapy with laser-driven accelerated particle beams: physical dosimetry and spatial dose distribution

Energy Technology Data Exchange (ETDEWEB)

Reinhardt, Sabine; Assmann, Walter [Ludwig-Maximilians Universitaet Muenchen (Germany); Kneschaurek, Peter; Wilkens, Jan [MRI, Technische Universitaet Muenchen (Germany)

2011-07-01

One of the main goals of the Munich Centre for Advanced Photonics (MAP) is the application of laser driven accelerated (LDA) particle beams for radiation therapy. Due to the unique acceleration process ultrashort particle pulses of high intensity (> 10{sup 7} particles /cm{sup 2}/ns) are generated, which makes online detection an ambitious task. So far, state of the art detection of laser accelerated ion pulses are non-electronic detectors like radiochromic films (RCF), imaging plates (IP) or nuclear track detectors (e.g. CR39). All these kind of detectors are offline detectors requiring several hours of processing time. For this reason they are not qualified for an application in radiation therapy where quantitative real time detection of the beam is an essential prerequisite. Therefore we are investigating pixel detectors for real time monitoring of LDA particle pulses. First tests of commercially available systems with 8-20 MeV protons are presented. For radiobiological experiments second generation Gafchromic films (EBT2) have been calibrated with protons of 12 and 20 MeV for a dose range of 0.3-10 Gy. Dose verification in proton irradiation of subcutaneous tumours in mice was successfully accomplished using these films.

Intense particle beam and multiple applications

International Nuclear Information System (INIS)

Ueda, M.; Machida, M.

1988-01-01

The Multiple Application Intense Particle Beam project is an experiment in which an injector of high energy neutral or ionized particles will be used to diagnose high density and high temperature plasmas. The acceleration of the particles will be carried out feeding a diode with a high voltage pulse produced by a Marx generator. Other apllications of intense particle beam generated by this injector that could be explored in the future include: heating and stabilization of compact toroids, treatment of metallic surfaces and ion implantation. (author) [pt

CAS Accelerators for Medical Applications in Vösendorf, Austria

CERN Multimedia

CERN Accelerator School

2015-01-01

The CERN Accelerator School (CAS) and MedAustron jointly organised a course on Accelerators for Medical Applications in Vösendorf, Austria between 26 May and 5 June 2015. The course was held at the Eventhotel Pyramide on the outskirts of Vienna, and was attended by 76 participants from 29 countries, coming from as far away as Canada, China, Lithuania, Thailand, Ukraine and Russia.       The intensive programme comprised 37 lectures. The emphasis was on using charged particle beams for cancer therapy and the programme began by covering the way in which particles interact with biological material, how this translates into the dose needed for treatment and how this dose is best delivered. The different accelerator options for providing the particles needed were then presented in some detail. The production of radioisotopes and how these are used for diagnostics and therapy was also covered, together with a look at novel acceleration techniques that may play a role i...

The acceleration of particles to high energy

International Nuclear Information System (INIS)

Parker, E.N.

1976-01-01

The common occurrence, and often spectacular consequence, of fast particles in active astrophysical bodies has attracted the attention of physicists for more than four decades. The acceleration mechanisms, whatever they may be, are remarkably efficient, converting a major fraction of the total energy into fast particles. A variety of ideas have arisen, suggesting how and why fast particles are generated in various circumstances. The principal limitation on particle acceleration theories has been the realization that the universe in not filled with a hard vacuum, but rather is pervaded everywhere by tenuous ionized gases quite able to short circuit any large-scale electric fields that occur under ordinary circumstances. A number of the early ideas on the acceleration of cosmic rays have been discarded for this reason. The basic theoretical ideas can be grouped roughly into five parts: 1. hydromagnetic fields; 2. field in reduced conductivity; 3. plasma turbulence; 4. low frequency electromagnetic waves; 5. supernova explosion. Each of these is considered in turn. (Auth.)

Multistage charged particle accelerator, with high-vacuum insulation

International Nuclear Information System (INIS)

Holl, P.

1976-01-01

A multistage charged-particle accelerator for operating with accelerating voltages higher than 150 kV is described. The device consists essentially of a high-voltage insulator, a source for producing charged particles, a Wehnelt cylinder, an anode, and a post-accelerating tube containing stack-wise positioned post-accelerating electrodes. A high vacuum is used for insulating the parts carrying the high voltages, and at least one cylindrical screen surrounding these parts is interposed between them and the vacuum vessel, which can itself also function as a cylindrical screen

Overview of Accelerator Applications for Security and Defense

Science.gov (United States)

Antolak, Arlyn J.

Particle accelerators play a key role in a broad set of defense and security applications, including war-fighter and asset protection, cargo inspection, nonproliferation, materials characterization, and stockpile stewardship. Accelerators can replace the high activity radioactive sources that pose a security threat to developing a radiological dispersal device, and, can be used to produce isotopes for medical, industrial, and research purposes. An overview of current and emerging accelerator technologies relevant to addressing the needs of defense and security is presented.

Particle Acceleration and Fractional Transport in Turbulent Reconnection

Science.gov (United States)

Isliker, Heinz; Pisokas, Theophilos; Vlahos, Loukas; Anastasiadis, Anastasios

2017-11-01

We consider a large-scale environment of turbulent reconnection that is fragmented into a number of randomly distributed unstable current sheets (UCSs), and we statistically analyze the acceleration of particles within this environment. We address two important cases of acceleration mechanisms when particles interact with the UCS: (a) electric field acceleration and (b) acceleration by reflection at contracting islands. Electrons and ions are accelerated very efficiently, attaining an energy distribution of power-law shape with an index 1-2, depending on the acceleration mechanism. The transport coefficients in energy space are estimated from test-particle simulation data, and we show that the classical Fokker-Planck (FP) equation fails to reproduce the simulation results when the transport coefficients are inserted into it and it is solved numerically. The cause for this failure is that the particles perform Levy flights in energy space, while the distributions of the energy increments exhibit power-law tails. We then use the fractional transport equation (FTE) derived by Isliker et al., whose parameters and the order of the fractional derivatives are inferred from the simulation data, and solving the FTE numerically, we show that the FTE successfully reproduces the kinetic energy distribution of the test particles. We discuss in detail the analysis of the simulation data and the criteria that allow one to judge the appropriateness of either an FTE or a classical FP equation as a transport model.

Particle Acceleration and Fractional Transport in Turbulent Reconnection

Energy Technology Data Exchange (ETDEWEB)

Isliker, Heinz; Pisokas, Theophilos; Vlahos, Loukas [Department of Physics, Aristotle University of Thessaloniki, GR-52124 Thessaloniki (Greece); Anastasiadis, Anastasios [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece)

2017-11-01

We consider a large-scale environment of turbulent reconnection that is fragmented into a number of randomly distributed unstable current sheets (UCSs), and we statistically analyze the acceleration of particles within this environment. We address two important cases of acceleration mechanisms when particles interact with the UCS: (a) electric field acceleration and (b) acceleration by reflection at contracting islands. Electrons and ions are accelerated very efficiently, attaining an energy distribution of power-law shape with an index 1–2, depending on the acceleration mechanism. The transport coefficients in energy space are estimated from test-particle simulation data, and we show that the classical Fokker–Planck (FP) equation fails to reproduce the simulation results when the transport coefficients are inserted into it and it is solved numerically. The cause for this failure is that the particles perform Levy flights in energy space, while the distributions of the energy increments exhibit power-law tails. We then use the fractional transport equation (FTE) derived by Isliker et al., whose parameters and the order of the fractional derivatives are inferred from the simulation data, and solving the FTE numerically, we show that the FTE successfully reproduces the kinetic energy distribution of the test particles. We discuss in detail the analysis of the simulation data and the criteria that allow one to judge the appropriateness of either an FTE or a classical FP equation as a transport model.

A practical guide to modern high energy particle accelerators

International Nuclear Information System (INIS)

Holmes, S.D.

1987-10-01

The purpose of these lectures is to convey an understanding of how particle accelerators work and why they look the way they do. The approach taken is physically intuitive rather than mathematically rigorous. The emphasis is on the description of proton circular accelerators and colliders. Linear accelerators are mentioned only in passing as sources of protons for higher energy rings. Electron accelerators/storage rings and antiproton sources are discussed only by way of brief descriptions of the features which distinguish them from proton accelerators. The basics of how generic accelerators work are discussed, focusing on descriptions of what sets the overall scale, single particle dynamics and stability, and descriptions of the phase space of the particle beam, the information thus presented is then used to go through the exercise of designing a Superconducting Super Collider

Sources and acceleration efficiencies for energetic particles in the heliosphere

International Nuclear Information System (INIS)

Kucharek, H; Moebius, E

2006-01-01

Shocks at solar wind stream interaction regions, coronal mass ejections and magnetospheric obstacles have long been known for their intimate link with particle acceleration. Much enhanced capabilities to determine mass and charge composition at interplanetary shocks with ACE and SOHO have enabled us to identify sources and acceleration processes for the energetic particles. Both solar wind and interstellar pickup ions are substantial sources for particle acceleration in corotating interaction regions and at coronal mass ejections driven shocks and that flare particles are re-accelerated. Suprathermal distributions, such as pickup ions and pre-existing flare populations are accelerated much more efficiently than particles out of the solar wind. Recent results of the termination shock crossing by Voyager I and the scientific goals of the upcoming IBEX mission will be discussed

Application of normal form methods to the analysis of resonances in particle accelerators

International Nuclear Information System (INIS)

Davies, W.G.

1992-01-01

The transformation to normal form in a Lie-algebraic framework provides a very powerful method for identifying and analysing non-linear behaviour and resonances in particle accelerators. The basic ideas are presented and illustrated. (author). 4 refs

Particle Acceleration, Magnetic Field Generation in Relativistic Shocks

Science.gov (United States)

Nishikawa, Ken-Ichi; Hardee, P.; Hededal, C. B.; Richardson, G.; Sol, H.; Preece, R.; Fishman, G. J.

2005-01-01

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating through an ambient plasma with and without initial magnetic fields. We find only small differences in the results between no ambient and weak ambient parallel magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates particles perpendicular and parallel to the jet propagation direction. New simulations with an ambient perpendicular magnetic field show the strong interaction between the relativistic jet and the magnetic fields. The magnetic fields are piled up by the jet and the jet electrons are bent, which creates currents and displacement currents. At the nonlinear stage, the magnetic fields are reversed by the current and the reconnection may take place. Due to these dynamics the jet and ambient electron are strongly accelerated in both parallel and perpendicular directions.

Charged particle accelerators for practice

International Nuclear Information System (INIS)

Arzumanov, A.A.

1988-01-01

Characteristics of some accelerators operating in the world are given, capabilities of accelerator technique are demonstrated. Examples of wide application of accelerators in radiation-chemical technology as well as for defectoscopy of massive metal products and impurity ion implantation when producing semiconductor elements are presented. Works on nuclear filter production are characterized by high efficiency. Wide application of synchrotron radiation is described. Various accelerators can be applied during element analysis in geology, metallurgy, ecology. Application of accelerators ''in particular, cyclotrons for radioisotope production as well as in radiotherapy in medicine appears to be important. An isochronous cyclotron with controlled ion energy, at which applied works concerning a number of considered trends in the field of radiation physics and radiation physical metallurgy, element analysis, radiation resistance of electronic circuits and components are conducted, is in operation at the IYaPh of the Kazakh Academy of Sciences. Production of tallium-201 for cardiologic invstigations deserves a special attention. An electrostatic heavy ion accelerator which allows one to produce the beams of accelerated ions of elements from hydrogen to uranium is under commissioning

From Particle Physics to Medical Applications

Science.gov (United States)

Dosanjh, Manjit

2017-06-01

CERN is the world's largest particle physics research laboratory. Since it was established in 1954, it has made an outstanding contribution to our understanding of the fundamental particles and their interactions, and also to the technologies needed to analyse their properties and behaviour. The experimental challenges have pushed the performance of particle accelerators and detectors to the limits of our technical capabilities, and these groundbreaking technologies can also have a significant impact in applications beyond particle physics. In particular, the detectors developed for particle physics have led to improved techniques for medical imaging, while accelerator technologies lie at the heart of the irradiation methods that are widely used for treating cancer. Indeed, many important diagnostic and therapeutic techniques used by healthcare professionals are based either on basic physics principles or the technologies developed to carry out physics research. Ever since the discovery of x-rays by Roentgen in 1895, physics has been instrumental in the development of technologies in the biomedical domain, including the use of ionizing radiation for medical imaging and therapy. Some key examples that are explored in detail in this book include scanners based on positron emission tomography, as well as radiation therapy for cancer treatment. Even the collaborative model of particle physics is proving to be effective in catalysing multidisciplinary research for medical applications, ensuring that pioneering physics research is exploited for the benefit of all.

Particle Accelerator Focus Automation

Directory of Open Access Journals (Sweden)

Lopes José

2017-08-01

Full Text Available The Laboratório de Aceleradores e Tecnologias de Radiação (LATR at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+ and proton (H+ beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.

Particle Accelerator Focus Automation

Science.gov (United States)

Lopes, José; Rocha, Jorge; Redondo, Luís; Cruz, João

2017-08-01

The Laboratório de Aceleradores e Tecnologias de Radiação (LATR) at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST) has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+) and proton (H+) beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.

Neural network based expert system for fault diagnosis of particle accelerators

International Nuclear Information System (INIS)

Dewidar, M.M.

1997-01-01

Particle accelerators are generators that produce beams of charged particles, acquiring different energies, depending on the accelerator type. The MGC-20 cyclotron is a cyclic particle accelerator used for accelerating protons, deuterons, alpha particles, and helium-3 to different energies. Its applications include isotope production, nuclear reaction, and mass spectroscopy studies. It is a complicated machine, it consists of five main parts, the ion source, the deflector, the beam transport system, the concentric and harmonic coils, and the radio frequency system. The diagnosis of this device is a very complex task. it depends on the conditions of 27 indicators of the control panel of the device. The accurate diagnosis can lead to a high system reliability and save maintenance costs. so an expert system for the cyclotron fault diagnosis is necessary to be built. In this thesis , a hybrid expert system was developed for the fault diagnosis of the MGC-20 cyclotron. Two intelligent techniques, multilayer feed forward back propagation neural network and the rule based expert system, are integrated as a pre-processor loosely coupled model to build the proposed hybrid expert system. The architecture of the developed hybrid expert system consists of two levels. The first level is two feed forward back propagation neural networks, used for isolating the faulty part of the cyclotron. The second level is the rule based expert system, used for troubleshooting the faults inside the isolated faulty part. 4-6 tabs., 4-5 figs., 36 refs

Particle acceleration by inverse-Weibel instability

International Nuclear Information System (INIS)

Kawata, S.

1996-01-01

A high demagnetization rate delta B/delta t can be obtained through fast decoupling of a magnetic field from an electric circuit which generates the magnetic field. Nowadays fast decoupling is possible by present switching technologies. A high particle-acceleration gradient can be obtained in an inductive acceleration system compared with that in a conventional induction accelerator. Based on this new proposal, inductive ion and electron accelerations were investigated numerically. The mechanism presented can be considered as pseudo-inverse Weibel instability. (author). 3 figs., 7 refs

Particle acceleration by inverse-Weibel instability

Energy Technology Data Exchange (ETDEWEB)

Kawata, S [Nagaoka Univ. of Technology (Japan). Dept. of Electrical Engineering

1997-12-31

A high demagnetization rate delta B/delta t can be obtained through fast decoupling of a magnetic field from an electric circuit which generates the magnetic field. Nowadays fast decoupling is possible by present switching technologies. A high particle-acceleration gradient can be obtained in an inductive acceleration system compared with that in a conventional induction accelerator. Based on this new proposal, inductive ion and electron accelerations were investigated numerically. The mechanism presented can be considered as pseudo-inverse Weibel instability. (author). 3 figs., 7 refs.

EXTREME PARTICLE ACCELERATION IN MAGNETIC RECONNECTION LAYERS: APPLICATION TO THE GAMMA-RAY FLARES IN THE CRAB NEBULA

Energy Technology Data Exchange (ETDEWEB)

Cerutti, Benoit; Uzdensky, Dmitri A. [CIPS, Physics Department, University of Colorado, UCB 390, Boulder, CO 80309-0390 (United States); Begelman, Mitchell C., E-mail: benoit.cerutti@colorado.edu, E-mail: uzdensky@colorado.edu, E-mail: mitch@jila.colorado.edu [JILA, University of Colorado and National Institute of Standards and Technology, UCB 440, Boulder, CO 80309-0440 (United States)

2012-02-20

The gamma-ray space telescopes AGILE and Fermi detected short and bright synchrotron gamma-ray flares at photon energies above 100 MeV in the Crab Nebula. This discovery suggests that electron-positron pairs in the nebula are accelerated to PeV energies in a milligauss magnetic field, which is difficult to explain with classical models of particle acceleration and pulsar wind nebulae. We investigate whether particle acceleration in a magnetic reconnection layer can account for the puzzling properties of the flares. We numerically integrate relativistic test-particle orbits in the vicinity of the layer, including the radiation reaction force, and using analytical expressions for the large-scale electromagnetic fields. As they get accelerated by the reconnection electric field, the particles are focused deep inside the current layer where the magnetic field is small. The electrons suffer less from synchrotron losses and are accelerated to extremely high energies. Population studies show that, at the end of the layer, the particle distribution piles up at the maximum energy given by the electric potential drop and is focused into a thin fan beam. Applying this model to the Crab Nebula, we find that the emerging synchrotron emission spectrum peaks above 100 MeV and is close to the spectral shape of a single electron. The flare inverse Compton emission is negligible and no detectable emission is expected at other wavelengths. This mechanism provides a plausible explanation for the gamma-ray flares in the Crab Nebula and could be at work in other astrophysical objects such as relativistic jets in active galactic nuclei.

EXTREME PARTICLE ACCELERATION IN MAGNETIC RECONNECTION LAYERS: APPLICATION TO THE GAMMA-RAY FLARES IN THE CRAB NEBULA

International Nuclear Information System (INIS)

Cerutti, Benoît; Uzdensky, Dmitri A.; Begelman, Mitchell C.

2012-01-01

The gamma-ray space telescopes AGILE and Fermi detected short and bright synchrotron gamma-ray flares at photon energies above 100 MeV in the Crab Nebula. This discovery suggests that electron-positron pairs in the nebula are accelerated to PeV energies in a milligauss magnetic field, which is difficult to explain with classical models of particle acceleration and pulsar wind nebulae. We investigate whether particle acceleration in a magnetic reconnection layer can account for the puzzling properties of the flares. We numerically integrate relativistic test-particle orbits in the vicinity of the layer, including the radiation reaction force, and using analytical expressions for the large-scale electromagnetic fields. As they get accelerated by the reconnection electric field, the particles are focused deep inside the current layer where the magnetic field is small. The electrons suffer less from synchrotron losses and are accelerated to extremely high energies. Population studies show that, at the end of the layer, the particle distribution piles up at the maximum energy given by the electric potential drop and is focused into a thin fan beam. Applying this model to the Crab Nebula, we find that the emerging synchrotron emission spectrum peaks above 100 MeV and is close to the spectral shape of a single electron. The flare inverse Compton emission is negligible and no detectable emission is expected at other wavelengths. This mechanism provides a plausible explanation for the gamma-ray flares in the Crab Nebula and could be at work in other astrophysical objects such as relativistic jets in active galactic nuclei.

Accelerating particles in general relativity (stationary C-metric)

International Nuclear Information System (INIS)

Farhoosh, H.

1979-01-01

The purpose of this thesis is to study the physical and geometrical properties of uniformly accelerating particles in the general theory of relativity and it consists of four main parts. In the first part the structure of the Killing horizons in the static vacuum C-metric which represents the gravitational field of a uniformly accelerating Schwarzschild like particle (non-rotating and spherically symmetric) is studied. In the second part these results are generalized to include the effects of the rotation of the source. For small acceleration and small rotation this solution reveals the existance of three Killing horizons. Two the these horizons are the Schwarzschild and the Rindler surfaces which are mainly due to the mass and the acceleration of the particle, respectively. In part three the radial geodesic and non-geodesic motions in the static vacuum C-metric (non-rotating case) are investigated. The effect of the dragging of the inertial frame is also shown in this part. In part four the radiative behavior of the stationary charged C-metric representing the electro-gravitational field of a uniformly accelerating and rotating charged particle with magnetic monopole and the NUT-parameter are investigated. The physical quantities - the news function, mass loss, mass, charge and the multipole moments - are calculated. It is also shown in this part that the magnetic monopole in the presence of rotation and acceleration affects the electric charge

Superconducting magnets for particle large accelerators

International Nuclear Information System (INIS)

Kircher, F.

1994-01-01

The different accelerator types (linear, circular) and the advantages of using superconductivity in particle accelerator are first reviewed. Characteristics of some large superconducting accelerators (Tevatron, HERA, RHIC, LHC CERN) are presented. The design features related to accelerator magnets are reviewed: magnet reproducibility, stability, field homogeneity, etc. and the selected design characteristics are discussed: manufacturing method, winding, shielding, cryostat. CEA involvement in this domain mainly addressing quadrupoles, is presented together with the Large Hadron Collider (LHC) project at CERN. Characteristics and design of detector magnets are also described. 5 figs., 2 tabs

Particle acceleration through the resonance of high magnetic field and high frequency electromagnetic wave

International Nuclear Information System (INIS)

Hong, Liu; He, X.T.; Chen, S.G.; Zhang, W.Y.; He, X.T.; Hong, Liu

2004-01-01

We propose a new particle acceleration mechanism. Electrons can be accelerated to relativistic energy within a few electromagnetic wave cycles through the mechanism which is named electromagnetic and magnetic field resonance acceleration (EMRA). We find that the electron acceleration depends not only on the electromagnetic wave intensity, but also on the ratio between electron Larmor frequency and electromagnetic wave frequency. As the ratio approaches to unity, a clear resonance peak is observed, corresponding to the EMRA. Near the resonance regime, the strong magnetic fields still affect the electron acceleration dramatically. We derive an approximate analytical solution of the relativistic electron energy in adiabatic limit, which provides a full understanding of this phenomenon. In typical parameters of pulsar magnetospheres, the mechanism allows particles to increase their energies through the resonance of high magnetic field and high frequency electromagnetic wave in each electromagnetic wave period. The energy spectra of the accelerated particles exhibit the synchrotron radiation behavior. These can help to understand the remaining emission of high energy electron from radio pulsar within supernova remnant. The other potential application of our theory in fast ignition scheme of inertial confinement fusion is also discussed. (authors)

ELIMAIA: A Laser-Driven Ion Accelerator for Multidisciplinary Applications

Directory of Open Access Journals (Sweden)

Daniele Margarone

2018-04-01

Full Text Available The main direction proposed by the community of experts in the field of laser-driven ion acceleration is to improve particle beam features (maximum energy, charge, emittance, divergence, monochromaticity, shot-to-shot stability in order to demonstrate reliable and compact approaches to be used for multidisciplinary applications, thus, in principle, reducing the overall cost of a laser-based facility compared to a conventional accelerator one and, at the same time, demonstrating innovative and more effective sample irradiation geometries. The mission of the laser-driven ion target area at ELI-Beamlines (Extreme Light Infrastructure in Dolní Břežany, Czech Republic, called ELI Multidisciplinary Applications of laser-Ion Acceleration (ELIMAIA , is to provide stable, fully characterized and tuneable beams of particles accelerated by Petawatt-class lasers and to offer them to the user community for multidisciplinary applications. The ELIMAIA beamline has been designed and developed at the Institute of Physics of the Academy of Science of the Czech Republic (IoP-ASCR in Prague and at the National Laboratories of Southern Italy of the National Institute for Nuclear Physics (LNS-INFN in Catania (Italy. An international scientific network particularly interested in future applications of laser driven ions for hadrontherapy, ELI MEDical applications (ELIMED, has been established around the implementation of the ELIMAIA experimental system. The basic technology used for ELIMAIA research and development, along with envisioned parameters of such user beamline will be described and discussed.

Particle acceleration by pulsars

International Nuclear Information System (INIS)

Arons, Jonathan.

1980-06-01

The evidence that pulsars accelerate relativistic particles is reviewed, with emphasis on the γ-ray observations. The current state of knowledge of acceleration in strong waves is summarized, with emphasis on the inability of consistent theories to accelerate very high energy particles without converting too much energy into high energy photons. The state of viable models for pair creation by pulsars is summarized, with the conclusion that pulsars very likely lose rotational energy in winds instead of in superluminous strong waves. The relation of the pair creation models to γ-ray observations and to soft X-ray observations of pulsars is outlined, with the conclusion that energetically viable models may exist, but none have yet yielded useful agreement with the extant data. Some paths for overcoming present problems are discussed. The relation of the favored models to cosmic rays is discussed. It is pointed out that the pairs made by the models may have observable consequences for observation of positrons in the local cosmic ray flux and for observations of the 511 keV line from the interstellar medium. Another new point is that asymmetry of plasma supply from at least one of the models may qualitatively explain the gross asymmetry of the X-ray emission from the Crab nebula. It is also argued that acceleration of cosmic ray nuclei by pulsars, while energetically possible, can occur only at the boundary of the bubbles blown by the pulsars, if the cosmic ray composition is to be anything like that of the known source spectrum

Acceleration of quasi-particle modes in Bose-Einstein condensates

OpenAIRE

Marzlin, Karl-Peter; Zhang, Weiping

1998-01-01

We analytically examine the dynamics of quasi-particle modes occuring in a Bose-Einstein condensate which is subject to a weak acceleration. It is shown that the momentum of a quasi-particle mode is squeezed rather than accelerated.

Some advances in medical applications of low energy accelerators

Science.gov (United States)

Valković, V.; Moschini, G.

1991-05-01

Medical applications of low energy accelerators include: the use of nuclear analytical methods and procedures for laboratory studies and routine measurements; material productions and modifications to meet special requirements; radioisotope productions and their applications in radiopharmaceuticals as well as in positron emission tomography; and radiotherapy with ions, based on improved understanding of the interaction of charged particles with living tissue. Some of the recent advances in these fields are critically summarized. The plan for an improved charged particle facility in a hospital environment dedicated to applications in biology and medicine is presented.

The Solar Flare: A Strongly Turbulent Particle Accelerator

Science.gov (United States)

Vlahos, L.; Krucker, S.; Cargill, P.

The topics of explosive magnetic energy release on a large scale (a solar flare) and particle acceleration during such an event are rarely discussed together in the same article. Many discussions of magnetohydrodynamic (MHD) mod- eling of solar flares and/or CMEs have appeared (see [143] and references therein) and usually address large-scale destabilization of the coronal mag- netic field. Particle acceleration in solar flares has also been discussed exten- sively [74, 164, 116, 166, 87, 168, 95, 122, 35] with the main emphasis being on the actual mechanisms for acceleration (e.g., shocks, turbulence, DC electric fields) rather than the global magnetic context in which the acceleration takes place.

The Los Alamos Laser Acceleration of Particles Workshop and beginning of the advanced accelerator concepts field

Science.gov (United States)

Joshi, C.

2012-12-01

The first Advanced Acceleration of Particles-AAC-Workshop (actually named Laser Acceleration of Particles Workshop) was held at Los Alamos in January 1982. The workshop lasted a week and divided all the acceleration techniques into four categories: near field, far field, media, and vacuum. Basic theorems of particle acceleration were postulated (later proven) and specific experiments based on the four categories were formulated. This landmark workshop led to the formation of the advanced accelerator R&D program in the HEP office of the DOE that supports advanced accelerator research to this day. Two major new user facilities at Argonne and Brookhaven and several more directed experimental efforts were built to explore the advanced particle acceleration schemes. It is not an exaggeration to say that the intellectual breadth and excitement provided by the many groups who entered this new field provided the needed vitality to then recently formed APS Division of Beams and the new online journal Physical Review Special Topics-Accelerators and Beams. On this 30th anniversary of the AAC Workshops, it is worthwhile to look back at the legacy of the first Workshop at Los Alamos and the fine groundwork it laid for the field of advanced accelerator concepts that continues to flourish to this day.

Neural Networks for Modeling and Control of Particle Accelerators

CERN Document Server

Edelen, A.L.; Chase, B.E.; Edstrom, D.; Milton, S.V.; Stabile, P.

2016-01-01

We describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.

Particle acceleration and reconnection in the solar wind

Energy Technology Data Exchange (ETDEWEB)

Zank, G. P.; Hunana, P.; Mostafavi, P.; Le Roux, J. A.; Webb, G. M. [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama, Huntsville, AL 35805 (United States); Department of Space Science, University of Alabama, Huntsville, AL 35899 (United States); Khabarova, O. [Heliophysical Laboratory, IZMIRAN, Troitsk, Moscow 142190 (Russian Federation); Cummings, A. C.; Stone, E. C. [California Institute of Technology, Mail Code 290-17, Pasadena, CA 91125 (United States); Decker, R. B. [Johns Hopkins University/Applied Physics Lab., Laurel, MD 20723-6099 (United States)

2016-03-25

An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized quasi-2D small-scale magnetic island reconnection processes. An advection-diffusion transport equation for a nearly isotropic particle distribution describes particle transport and energization in a region of interacting magnetic islands [1; 2]. The dominant charged particle energization processes are 1) the electric field induced by quasi-2D magnetic island merging, and 2) magnetic island contraction. The acceleration of charged particles in a “sea of magnetic islands” in a super-Alfvénic flow, and the energization of particles by combined diffusive shock acceleration (DSA) and downstream magnetic island reconnection processes are discussed.

On the Relativistic Correction of Particles Trajectory in Tandem Type Electrostatic Accelerator

Science.gov (United States)

Minárik, Stanislav

2015-08-01

A constant potential is applied to the acceleration of the ion-beam in the tandem type electrostatic accelerator. However, not just one voltage is applied, but instead a number of applications can be made in succession by means of the tandem arrangement of high voltage tubes. This number of voltage applications, which is the number of so-called "stages" of a tandem accelerator, may be two, three, or four, depending on the chosen design. Electrostatic field with approximately constant intensity acts on ions in any stage. In general, non-relativistic dynamics is used for the description of the ion transport in tandem accelerator. Energies of accelerated ions are too low and relativistic effects cannot be commonly observed by standard experimental technique. Estimation of possible relativistic correction of ion trajectories is therefore only a matter of calculation. In this note, we briefly present such calculation. Our aim is to show how using the relativistic dynamics modifies the particles trajectory in tandem type accelerator and what parameters determine this modification.

Feasibility study on the construction and utilization of charged particle accelerators

International Nuclear Information System (INIS)

Cho, S.W.; Chung, M.K.; Choe, B.H.; Lee, K.W.; In, S.Y.; Park, I.S.; Kang, S.S.

1981-01-01

This is a report on the thorough studies of feasible accelerator to be constructed in Korea from various aspects. By following the brief descriptions on the operational principles and applications of various types of particle accelerators, estimations of required budgeting for construction and operation of those accelerators are given in detail. From the forecasted availability of government investment to accelerator project and also from the expected great role of accelerators to be played for nuclear power developments, we draw three steps' development program of accelerator technology in Korea. The first step is mainly aimed to user development and accumulation of accelerator technology through the construction and utilization of 50-100MeV electron linear accelerator. The second step to be recommended is the construction of 20-30MeV proton linear accelerator which can be used as an injector for future proton synchrotron. The third step is construction and utilization of several GeV proton synchrotron. However, development of accelerator technology in advanced countries is so fast that above-mentioned second and third step may not be regarded to be definite plans

Advanced visualization technology for terascale particle accelerator simulations

International Nuclear Information System (INIS)

Ma, K-L; Schussman, G.; Wilson, B.; Ko, K.; Qiang, J.; Ryne, R.

2002-01-01

This paper presents two new hardware-assisted rendering techniques developed for interactive visualization of the terascale data generated from numerical modeling of next generation accelerator designs. The first technique, based on a hybrid rendering approach, makes possible interactive exploration of large-scale particle data from particle beam dynamics modeling. The second technique, based on a compact texture-enhanced representation, exploits the advanced features of commodity graphics cards to achieve perceptually effective visualization of the very dense and complex electromagnetic fields produced from the modeling of reflection and transmission properties of open structures in an accelerator design. Because of the collaborative nature of the overall accelerator modeling project, the visualization technology developed is for both desktop and remote visualization settings. We have tested the techniques using both time varying particle data sets containing up to one billion particle s per time step and electromagnetic field data sets with millions of mesh elements

Chicago particle accelerator conference

International Nuclear Information System (INIS)

Southworth, Brian

1989-01-01

Naturally, emphasis at the Particle Accelerator Conference in Chicago in March was on work in the US, just as the newly instituted European Particle Accelerator Conference places emphasis on work in the 'old continent'. All will come together at the international conference in Japan in August. The proposed US Superconducting Supercollider (SSC) was highlighted in the opening talk at Chicago. Progress on this inchoate project to explore the TeV (1000 GeV) energy region by colliding 20 TeV proton beams was reported by the recently-appointed Director of the SSC Laboratory, Roy Schwitters. He reviewed the physics challenges and described progress and plans towards full authorization of construction.This year, the SSC conceptual design will be transformed into a 'site specific' report, now that the location at Waxahachie in Ellis County, Texas, has been selected. The Central Design Group, based in Berkeley for the past few years, will soon move to the Waxahachie region. The top management structure is taking shape and an International Advisory Committee is being formed

Chicago particle accelerator conference

Energy Technology Data Exchange (ETDEWEB)

Southworth, Brian

1989-06-15

Naturally, emphasis at the Particle Accelerator Conference in Chicago in March was on work in the US, just as the newly instituted European Particle Accelerator Conference places emphasis on work in the 'old continent'. All will come together at the international conference in Japan in August. The proposed US Superconducting Supercollider (SSC) was highlighted in the opening talk at Chicago. Progress on this inchoate project to explore the TeV (1000 GeV) energy region by colliding 20 TeV proton beams was reported by the recently-appointed Director of the SSC Laboratory, Roy Schwitters. He reviewed the physics challenges and described progress and plans towards full authorization of construction.This year, the SSC conceptual design will be transformed into a 'site specific' report, now that the location at Waxahachie in Ellis County, Texas, has been selected. The Central Design Group, based in Berkeley for the past few years, will soon move to the Waxahachie region. The top management structure is taking shape and an International Advisory Committee is being formed.

Particle accelerators test cosmological theory

International Nuclear Information System (INIS)

Schramm, D.N.; Steigman, G.

1988-01-01

Over the past decade two subfields of science, cosmology and elementary-particle physics, have become married in a symbiotic relationship that has produced a number of exciting offspring. These offspring are beginning to yield insights on the creation of spacetime and matter at epochs as early as 10 to the minus 43 to 10 to the minus 35 second after the birth of the universe in the primordial explosion known as the big bang. Important clues to the nature of the big bang itself may even come from a theory currently under development, known as the ultimate theory of everything (T.E.O.). A T.E.O. would describe all the interactions among the fundamental particles in a single bold stroke. Now that cosmology ahs begun to make predictions about elementary-particle physics, it has become conceivable that those cosmological predictions could be checked with carefully controlled accelerator experiments. It has taken more than 10 years for accelerators to reach the point where they can do the appropriate experiments, but the experiments are now in fact in progress. The preliminary results confirm the predictions of cosmology. The cosmological prediction the authors have been concerned with pertains to setting limits on the number of fundamental particles of matter. It appears that there are 12 fundamental particles, as well as their corresponding antiparticles. Six of the fundamental particles are quarks. The other six are leptons. The 12 particles are grouped in three families, each family consisting of four members. Cosmology suggests there must be a finite number of families and, further limits the possible range of to small values: only three or at most four families exist. 7 figs

Self focusing in a spatially modulated electrostatic field particle accelerator

Science.gov (United States)

Russman, F.; Marini, S.; Peter, E.; de Oliveira, G. I.; Rizzato, F. B.

2018-02-01

In the present analysis, we study the action of a three-dimensional (3D) modulated electrostatic wave over a charged particle. Meanwhile, the particle's velocity is smaller than the phase-velocity of the carrier, and the particle could be reflected by the potential or could pass through the potential with no significant change in the longitudinal velocity—and its dynamics could be described by a ponderomotive approximation. Otherwise, the particle is trapped by the potential and it is accelerated towards the speed of light, independently of the initial particle's phase—in this case, the ponderomotive approximation is no longer valid. During the acceleration process, numerical simulations show the particle is focused, simultaneously. These results suggest the accelerator proposed here is promising.

The acceleration and propagation of solar energetic particles

International Nuclear Information System (INIS)

Dalla, Silvia

2004-01-01

During flares and coronal mass ejections at the Sun, ions and electrons can be accelerated to high energies. They can escape from the solar corona into interplanetary space, and be detected by instruments on board spacecraft. This paper will review measurements of these solar energetic particles (SEPs) and models of their acceleration and propagation.It is generally agreed that SEP flux enhancements fall into two distinct classes: the so-called impulsive events, thought to originate in solar flares, and gradual events, thought to be the result of acceleration at the shock driven through the corona and interplanetary space by coronal mass ejections. A fundamental assumption of this model for SEPs is that particles' guiding centers propagate essentially parallel to the interplanetary magnetic field lines, and cross-field particle diffusion is negligible.The recent passage of the Ulysses spacecraft over the solar poles provided the first ever measurements of SEPs out of the ecliptic plane. Analysis of these data has revealed several fundamental differences with respect to the near-ecliptic measurements, such as large delays in particle arrival and in fluxes reaching their peak value. It will be shown that the current model of SEP acceleration and propagation does not account for the Ulysses results, which would more easily be explained by efficient cross-field diffusion of energetic particles

Application of the reduction of scale range in a Lorentz boosted frame to the numerical simulation of particle acceleration devices

International Nuclear Information System (INIS)

Vay, J.; Fawley, W.M.; Geddes, C.G.; Cormier-Michel, E.; Grote, D.P.

2009-01-01

It has been shown that the ratio of longest to shortest space and time scales of a system of two or more components crossing at relativistic velocities is not invariant under Lorentz transformation. This implies the existence of a frame of reference minimizing an aggregate measure of the ratio of space and time scales. It was demonstrated that this translated into a reduction by orders of magnitude in computer simulation run times, using methods based on first principles (e.g., Particle-In-Cell), for particle acceleration devices and for problems such as: free electron laser, laser-plasma accelerator, and particle beams interacting with electron clouds. Since then, speed-ups ranging from 75 to more than four orders of magnitude have been reported for the simulation of either scaled or reduced models of the above-cited problems. In it was shown that to achieve full benefits of the calculation in a boosted frame, some of the standard numerical techniques needed to be revised. The theory behind the speed-up of numerical simulation in a boosted frame, latest developments of numerical methods, and example applications with new opportunities that they offer are all presented

Particle Tracking in Circular Accelerators Using the Exact Hamiltonian in SixTrack

CERN Document Server

Fjellstrom, Mattias; Hansson, Johan

2013-12-13

Particle motion in accelerators is in general complex. Tracking codes are developed to simulate beam dynamics in accelerators. SixTrack is a long lived particle tracking code maintained at CERN, the European Organization for Nuclear Research. A particle accelerator consists of a large number of magnets and other electromagnetic devices that guide the particle through the accelerator. Each device defines its own equation of motion, which often cannot be solved exactly. For this purpose, a number of approximations are introduced in order to facilitate the solution and to speed up the computation. In a high-energy accelerator, the particle has small transverse momentum components. This is exploited in the small-angle approximation. In this approximation the equations of motion are expanded to a low order in the transverse momentum components. In low-energy particle accelerators, or in tracking with large momentum deviations, this approximation is invalid. The equations of motion of a particle passing through a f...

Particle acceleration and injection problem in relativistic and nonrelativistic shocks

International Nuclear Information System (INIS)

Hoshino, M.

2008-01-01

Acceleration of charged particles at the collisionless shock is believed to be responsible for production of cosmic rays in a variety of astrophysical objects such as supernova, AGN jet, and GRB etc., and the diffusive shock acceleration model is widely accepted as a key process for generating cosmic rays with non-thermal, power-law energy spectrum. Yet it is not well understood how the collisionless shock can produce such high energy particles. Among several unresolved issues, two major problems are the so-called '' injection '' problem of the supra-thermal particles and the generation of plasma waves and turbulence in and around the shock front. With recent advance of computer simulations, however, it is now possible to discuss those issues together with dynamical evolution of the kinetic shock structure. A wealth of modern astrophysical observations also inspires the dynamical shock structure and acceleration processes along with the theoretical and computational studies on shock. In this presentation, we focus on the plasma wave generation and the associated particle energization that directly links to the injection problem by taking into account the kinetic plasma processes of both non-relativistic and relativistic shocks by using a particle-in-cell simulation. We will also discuss some new particle acceleration mechanisms such as stochastic surfing acceleration and wakefield acceleration by the action of nonlinear electrostatic fields. (author)

Turbulence, Magnetic Reconnection in Turbulent Fluids and Energetic Particle Acceleration

Science.gov (United States)

Lazarian, A.; Vlahos, L.; Kowal, G.; Yan, H.; Beresnyak, A.; de Gouveia Dal Pino, E. M.

2012-11-01

Turbulence is ubiquitous in astrophysics. It radically changes many astrophysical phenomena, in particular, the propagation and acceleration of cosmic rays. We present the modern understanding of compressible magnetohydrodynamic (MHD) turbulence, in particular its decomposition into Alfvén, slow and fast modes, discuss the density structure of turbulent subsonic and supersonic media, as well as other relevant regimes of astrophysical turbulence. All this information is essential for understanding the energetic particle acceleration that we discuss further in the review. For instance, we show how fast and slow modes accelerate energetic particles through the second order Fermi acceleration, while density fluctuations generate magnetic fields in pre-shock regions enabling the first order Fermi acceleration of high energy cosmic rays. Very importantly, however, the first order Fermi cosmic ray acceleration is also possible in sites of magnetic reconnection. In the presence of turbulence this reconnection gets fast and we present numerical evidence supporting the predictions of the Lazarian and Vishniac (Astrophys. J. 517:700-718, 1999) model of fast reconnection. The efficiency of this process suggests that magnetic reconnection can release substantial amounts of energy in short periods of time. As the particle tracing numerical simulations show that the particles can be efficiently accelerated during the reconnection, we argue that the process of magnetic reconnection may be much more important for particle acceleration than it is currently accepted. In particular, we discuss the acceleration arising from reconnection as a possible origin of the anomalous cosmic rays measured by Voyagers as well as the origin cosmic ray excess in the direction of Heliotail.

Nonlinear theory of diffusive acceleration of particles by shock waves

Energy Technology Data Exchange (ETDEWEB)

Malkov, M.A. [University of California at San Diego, La Jolla, CA (United States)]. E-mail: mmalkov@ucsd.edu; Drury, L. O' C. [Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2 (Ireland)

2001-04-01

Among the various acceleration mechanisms which have been suggested as responsible for the nonthermal particle spectra and associated radiation observed in many astrophysical and space physics environments, diffusive shock acceleration appears to be the most successful. We review the current theoretical understanding of this process, from the basic ideas of how a shock energizes a few reactionless particles to the advanced nonlinear approaches treating the shock and accelerated particles as a symbiotic self-organizing system. By means of direct solution of the nonlinear problem we set the limit to the test-particle approximation and demonstrate the fundamental role of nonlinearity in shocks of astrophysical size and lifetime. We study the bifurcation of this system, proceeding from the hydrodynamic to kinetic description under a realistic condition of Bohm diffusivity. We emphasize the importance of collective plasma phenomena for the global flow structure and acceleration efficiency by considering the injection process, an initial stage of acceleration and, the related aspects of the physics of collisionless shocks. We calculate the injection rate for different shock parameters and different species. This, together with differential acceleration resulting from nonlinear large-scale modification, determines the chemical composition of accelerated particles. The review concentrates on theoretical and analytical aspects but our strategic goal is to link the fundamental theoretical ideas with the rapidly growing wealth of observational data. (author)

Where does particle acceleration occur in extended extragalactic radio sources

International Nuclear Information System (INIS)

Hughes, P.A.

1980-01-01

It is suggested that particle acceleration does not occur in the extended lobes of extragalactic radio sources, but only in the compact heads. Away from these, waves capable of accelerating particles may not propagate. Although wave generation within the lobes would allow acceleration there, it is not obvious that the plasma is sufficiently disturbed for this to occur. (author)

Report of promotion expert commission for radiation application on 'Promotion of accelerator application study'

International Nuclear Information System (INIS)

1997-01-01

This is a report published on June, 1996, by promotion expert commission for radiation application of the Atomic Energy Commission. Japanese research and development in the fields of forming and application techniques of radiation beams using accelerator is at comparatively high level in the world, and it seems to be important for Japan not only to maintain these research and development level but also to contribute to creation of worldwide intelligent welfare due to scientific technology. In this report, some investigations are conducted on present state and future view of the radiation application study using accelerator, accelerator facility necessary to promote such application study and a procedure to execute its smooth application. However, objects of the study are not limited only for physical study on elementary particle and atomic nucleus, but expanded to photon, electron, positron, muon, proton, neutron, various inonic beams and RI beams for radiations, which are widely applied to industries such as materials science, material engineering, bio-and life-science, medical science, technical engineering, and so forth, and which will be expected for large contribution to development of these industries. The following items are discussed here; 1) present state and future view of radiation application study using accelerator, 2) Accelerator to be prepared and its executing method, and 3) Promotion method of the accelerator application study. (G.K.)

Novel methods in the Particle-In-Cell accelerator Code-Framework Warp

Energy Technology Data Exchange (ETDEWEB)

Vay, J-L [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Grote, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cohen, R. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Friedman, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2012-12-26

The Particle-In-Cell (PIC) Code-Framework Warp is being developed by the Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) to guide the development of accelerators that can deliver beams suitable for high-energy density experiments and implosion of inertial fusion capsules. It is also applied in various areas outside the Heavy Ion Fusion program to the study and design of existing and next-generation high-energy accelerators, including the study of electron cloud effects and laser wakefield acceleration for example. This study presents an overview of Warp's capabilities, summarizing recent original numerical methods that were developed by the HIFS-VNL (including PIC with adaptive mesh refinement, a large-timestep 'drift-Lorentz' mover for arbitrarily magnetized species, a relativistic Lorentz invariant leapfrog particle pusher, simulations in Lorentz-boosted frames, an electromagnetic solver with tunable numerical dispersion and efficient stride-based digital filtering), with special emphasis on the description of the mesh refinement capability. In addition, selected examples of the applications of the methods to the abovementioned fields are given.

Civilian applications of particle-beam-initiated inertial confinement fusion technology

International Nuclear Information System (INIS)

Varnado, S.G.; Mitchiner, J.L.

1977-05-01

Electrical power generation by controlled fusion may provide a partial solution to the world's long-term energy supply problem. Achievement of a fusion reaction requires the confinement of an extremely hot plasma for a time long enough to allow fuel burnup. Inertial confinement of the plasma may be possible through the use of tightly focused, relativistic electron or ion beams to compress a fuel pellet. The Sandia Particle Beam Fusion program is developing the particle-beam accelerators necessary to achieve fuel ignition. In this report we review the status of the particle-beam fusion technology development program and identify several potential civilian applications for this technology. We describe program objectives, discuss the specific accelerators presently under development, and briefly review the results of beam-focusing and target-irradiation experiments. Then we identify and discuss applications for the beam technology and for the fusion neutrons. The applications are grouped into near-term, intermediate-term, and long-term categories. Near-term applications for the beam technology include electron-beam (e-beam) pumping of gas lasers and several commercial applications. Intermediate-term applications (pellet gain less than 50) include hybrid reactors for electrical power production and fissile fuel breeding, pure fusion reactors for electrical power production, and medical therapy using ion accelerators. In the long term, complex, high-gain pellets may be used in pure fusion reactors

Argonne lectures on particles accelerator magnets

International Nuclear Information System (INIS)

Devred, A.

1999-09-01

The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundred to several thousand) high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high-current-density, low-critical-temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (lecture 1), we briefly recall the origins of superconductivity and we review the parameters of existing superconducting particle accelerators (lecture 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb 3 Sn) and we explain in details the manufacturing of NbTi wires and cables (lecture 3). We also present the difficulties of processing and insulating Nb 3 Sn conductors, which so far have limited the use of this material in spite of its superior performances. We continue by discussing the two dimensional current distributions which are the most appropriate for generating pure dipole and quadrupole fields and we explain how these ideal distributions can be approximated by so called cosθ and cos 2θ coil designs (lecture 4). We also present a few alternative designs which are being investigated and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that are used in existing accelerator magnets (lecture 5) and we describe how the magnets are assembled (lecture 6). Some of the toughest requirements on the

Argonne lectures on particles accelerator magnets

Energy Technology Data Exchange (ETDEWEB)

Devred, A

1999-09-01

The quest for elementary particles has promoted the development of particle accelerators producing beams of increasingly higher energies. In a synchrotron, the particle energy is directly proportional to the product of the machine's radius times the bending magnets' field strength. Present proton experiments at the TeV scale require facilities with circumferences ranging from a few to tens of kilometers and relying on a large number (several hundred to several thousand) high field dipole magnets and high field gradient quadrupole magnets. These electro-magnets use high-current-density, low-critical-temperature superconducting cables and are cooled down at liquid helium temperature. They are among the most costly and the most challenging components of the machine. After explaining what are the various types of accelerator magnets and why they are needed (lecture 1), we briefly recall the origins of superconductivity and we review the parameters of existing superconducting particle accelerators (lecture 2). Then, we review the superconducting materials that are available at industrial scale (chiefly, NbTi and Nb{sub 3}Sn) and we explain in details the manufacturing of NbTi wires and cables (lecture 3). We also present the difficulties of processing and insulating Nb{sub 3}Sn conductors, which so far have limited the use of this material in spite of its superior performances. We continue by discussing the two dimensional current distributions which are the most appropriate for generating pure dipole and quadrupole fields and we explain how these ideal distributions can be approximated by so called cos{theta} and cos 2{theta} coil designs (lecture 4). We also present a few alternative designs which are being investigated and we describe the difficulties of realizing coil ends. Next, we present the mechanical design concepts that are used in existing accelerator magnets (lecture 5) and we describe how the magnets are assembled (lecture 6). Some of the toughest

Particle acceleration and shock wave structure

International Nuclear Information System (INIS)

DRURY, L.O'C.

1989-01-01

A significant determinant in the large-scale structure and evolution of strong collisionless shocks under astrophysical conditions is probably the acceleration of charged particles. The reaction of these particles on the dynamical structure of the shock wave is discussed both theoretically and in the light of recent numerical calculations. Astrophysical implications for the evolution of supernova remnants, are considered. (author). 15 refs

Radiological protection aspects on particle accelerators; Aspek perlindungan radiologi pada pemecut zarah

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-12-31

The chapter briefly discussed the following subjects: 1. Particle accelerators i.e. low energy accelerators (Van De Graaf generator, drift tube accelerator), high energy accelerators, cyclotrons, 2. dangerous source from particle accelerators, 3. X-ray and activation products, 4. bremstrahlung, 5. monitoring of workers and working place for neutron.

Particle Acceleration and Heating Processes at the Dayside Magnetopause

Science.gov (United States)

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

2017-12-01

It is well established that electrons and ions are accelerated and heated during magnetic reconnection at the dayside magnetopause. However, a detailed description of the actual physical mechanisms driving these processes and where they are operating is still incomplete. Many basic mechanisms are known to accelerate particles, including resonant wave-particle interactions as well as stochastic, Fermi, and betatron acceleration. In addition, acceleration and heating processes can occur over different scales. We have carried out kinetic simulations to investigate the mechanisms by which electrons and ions are accelerated and heated at the dayside magnetopause. The simulation model uses the results of global magnetohydrodynamic (MHD) simulations to set the initial state and the evolving boundary conditions of fully kinetic implicit particle-in-cell (iPic3D) simulations for different solar wind and interplanetary magnetic field conditions. This approach allows us to include large domains both in space and energy. In particular, some of these regional simulations include both the magnetopause and bow shock in the kinetic domain, encompassing range of particle energies from a few eV in the solar wind to keV in the magnetospheric boundary layer. We analyze the results of the iPic3D simulations by discussing wave spectra and particle velocity distribution functions observed in the different regions of the simulation domain, as well as using large-scale kinetic (LSK) computations to follow particles' time histories. We discuss the relevance of our results by comparing them with local observations by the MMS spacecraft.

Single-particle dynamics - RF acceleration

International Nuclear Information System (INIS)

Montague, B.W.

1977-01-01

In this paper the rf acceleration of both synchronous and non-synchronous particles is discussed and a simple linearized equation of small amplitude synchrotron oscillations is derived. Phase stability, the hamiltonian for synchrotron oscillations, oscillation amplitudes and adiabatic damping are then briefly discussed. The final sections of the paper contain a description of the basic principles of rf beam stacking in the longitudinal phase space of intersecting Storage Rings and a description of phase displacement acceleration which inspite of certain disadvantages, remains an attractive technique for proton storage rings. (B.D.)

New ideas for accelerating particles

International Nuclear Information System (INIS)

Lawson, J.D.

1983-01-01

Many different schemes can be devised for accelerating particles. In recent years several concepts radically different from those in common use have been suggested. Many of these have failed to live up to the hopes of their inventors. Now that we seem near the end of the road for large conventional machines, there is a renewed interest in alternatives, especially those involving lasers. Afte After a brief historical introduction and a discussion on how to classify different types of accelerator, some of these alternative concepts will be reviewed. (author)

Filament supply circuit for particle accelerator

International Nuclear Information System (INIS)

Thompson, C.C. Jr.; Malone, H.F.

1975-01-01

In a particle accelerator of the type employing ac primary power and a voltage multiplication apparatus to achieve the required high dc accelerating voltage, a filament supply circuit is powered by a portion of the ac primary power appearing at the last stage of the voltage multiplier. This ac power is applied across a voltage regulator circuit in the form of two zener diodes connected back to back. The threshold of the zeners is below the lowest peak-to-peak voltage of the ac voltage, so that the regulated voltage remains constant for all settings of the adjustable acceleration voltage. The regulated voltage is coupled through an adjustable resistor and an impedance-matching transformer to the accelerator filament. (auth)

The periodically pulsed mode of operation of magnet systems in particle accelerators

International Nuclear Information System (INIS)

Stange, G.

1980-01-01

Since in many applications in particle accelerator technology the beam duty factor, defined by the ratio of beam pulse length to the pulse to pulse period, is very small- typically in the order of 10 - 3 to 10 - 9 - it is interesting to operate the beam optical magnetic system in the periodically pulsed mode as well. Thus, by reducing the average Ohmic losses, it is possible to save energy and material. The pulsed mode of operation of magnet systems is especially adapted to those of linear accelerators and their beam transport systems, since linear accelerators are exclusively operated in this mode. But it is equally suitable for transport systems between cyclic accelerators and large storage rings as they are under development at present. (orig./WL) [de

Acceleration of low energy charged particles by gravitational waves

Energy Technology Data Exchange (ETDEWEB)

Voyatzis, G. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)]. E-mail: voyatzis@auth.gr; Vlahos, L. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Ichtiaroglou, S. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece); Papadopoulos, D. [University of Thessaloniki, Department of Physics, 54124 Thessaloniki (Greece)

2006-04-03

The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state.

Acceleration of low energy charged particles by gravitational waves

International Nuclear Information System (INIS)

Voyatzis, G.; Vlahos, L.; Ichtiaroglou, S.; Papadopoulos, D.

2006-01-01

The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state

First order and second order fermi acceleration of energetic charged particles by shock waves

International Nuclear Information System (INIS)

Webb, G.M.

1983-01-01

Steady state solutions of the cosmic ray transport equation describing first order Fermi acceleration of energetic charged particles at a plane shock (without losses) and second order Fermi acceleration in the downstream region of the shock are derived. The solutions for the isotropic part of the phase space distribution function are expressible as eigenfunction expansions, being superpositions of series of power law momentum spectra, with the power law indices being the roots of an eigenvalue equation. The above exact analytic solutions are for the case where the spatial diffusion coefficient kappa is independent of momentum. The solutions in general depend on the shock compression ratio, the modulation parameters V 1 L/kappa 1 , V 2 L/kappa 2 (V is the plasma velocity, kappa is the energetic particle diffusion coefficient, and L a characteristic length over which second order Fermi acceleration is effective) in the upstream and downstream regions of the shock, respectively, and also on a further dimensionless parameter, zeta, characterizing second order Fermi acceleration. In the limit as zeta→0 (no second order Fermi acceleration) the power law momentum spectrum characteristic of first order Fermi acceleration (depending only on the shock compression ratio) obtained previously is recovered. Perturbation solutions for the case where second order Fermi effects are small, and for realistic diffusion coefficients (kappainfinityp/sup a/, a>0, p = particle momentum), applicable at high momenta, are also obtained

Power Supplies for High Energy Particle Accelerators

Science.gov (United States)

Dey, Pranab Kumar

2016-06-01

The on-going research and the development projects with Large Hadron Collider at CERN, Geneva, Switzerland has generated enormous enthusiasm and interest amongst all to know about the ultimate findings on `God's Particle'. This paper has made an attempt to unfold the power supply requirements and the methodology adopted to provide the stringent demand of such high energy particle accelerators during the initial stages of the search for the ultimate particles. An attempt has also been made to highlight the present status on the requirement of power supplies in some high energy accelerators with a view that, precautionary measures can be drawn during design and development from earlier experience which will be of help for the proposed third generation synchrotron to be installed in India at a huge cost.

Grid Connected Power Supplies for Particle Accelerator Magnets

DEFF Research Database (Denmark)

Nielsen, Rasmus Ørndrup

Power supplies play a large role in particle accelerators, for creating, accelerating, steering and shaping the beam. This thesis covers the power supplies for steering and shaping the beam, namely the magnet power supplies. These power supplies have a special set of requirements regarding output...... on this topology is constructed using a single power module on the grid side of the transformer, consisting of a boost rectifier and a dual half-bridge isolated DC/DC converter. It is shown that it is possible to create a power supply using a single module and that this approach can lead to improved layout...... and smaller converter size. A high efficiency converter based on Silicon Carbide switching devices is also presented exhibiting above 96 % efficiency for the entire power range. Finally reliability issues are considered as the reliability of a particle accelerator supply is of utmost importance. Particle...

Accelerators for Medicine

CERN Multimedia

CERN. Geneva

2018-01-01

This lecture will review the different applications of particle accelerators to the medical field, from cancer treatment with beams of accelerator-produced particles (photons, electrons, protons, ions and neutrons) to the generation of radioactive isotopes used in medical diagnostics, in cancer therapy and in the new domain of theragnostics. For each application will be outlined the state of the art, the potential, and the accelerator challenges to be faced to meet the increasing demand for therapeutic procedures based on accelerators.

High energy particle accelerators as radiation Sources

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, M E [National Center for Nuclear Safety and Radiation Vontrol, Atomic Energy Authority, Cairo (Egypt)

1997-12-31

Small accelerators in the energy range of few million electron volts are usually used as radiation sources for various applications, like radiotherapy, food irradiation, radiation sterilization and in other industrial applications. High energy accelerators with energies reaching billions of electron volts also find wide field of applications as radiation sources. Synchrotrons with high energy range have unique features as radiation sources. This review presents a synopsis of cyclic accelerators with description of phase stability principle of high energy accelerators with emphasis on synchrotrons. Properties of synchrotron radiation are given together with their applications in basic and applied research. 13 figs.,1 tab.

Particle optics and accelerator modeling software for industrial and laboratory beamline design

International Nuclear Information System (INIS)

Gillespie, G.H.; Hill, B.W.

1998-01-01

The expanding variety of accelerator applications in research and industry places increased demands upon scientists and engineers involved in developing new accelerator and beamline designs. Computer codes for particle optics simulation have always played an important role in the design process and enhanced software tools offer the promise of improved productivity for beamline designers. This paper summarizes recent work on the development of advanced graphic user interface (GUI) software components, that can be linked directly to many of the standard particle optics programs used in the accelerator community, and which are aimed at turning that promise of improved productivity into a reality. An object oriented programming (OOP) approach has been adopted and a number of GUI components have been developed that run on several different operating systems. The emphasis is on assisting users in the setup and running of the optics programs without requiring any knowledge of the format, syntax, or similar requirements of the input. The components are being linked with several popular optics programs, including TRANSPORT, TURTLE, TRACE 3-D and PARMILA, to form integrated easy-to-use applications. Several advanced applications linking the GUI components with Lie algebra and other high-order simulation codes, as well as system level and facility modeling codes, are also under development. An overview of the work completed to date is presented, and examples of the new tools running on the Windows 95 operating system are illustrated. (orig.)

On the Radio-emitting Particles of the Crab Nebula: Stochastic Acceleration Model

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Shuta J. [Department of Physics, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Kobe, Hyogo 658-8501 (Japan); Asano, Katsuaki, E-mail: sjtanaka@center.konan-u.ac.jp [Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa City, Chiba, 277-8582 (Japan)

2017-06-01

The broadband emission of pulsar wind nebulae (PWNe) is well described by non-thermal emissions from accelerated electrons and positrons. However, the standard shock acceleration model of PWNe does not account for the hard spectrum in radio wavelengths. The origin of the radio-emitting particles is also important to determine the pair production efficiency in the pulsar magnetosphere. Here, we propose a possible resolution for the particle energy distribution in PWNe; the radio-emitting particles are not accelerated at the pulsar wind termination shock but are stochastically accelerated by turbulence inside PWNe. We upgrade our past one-zone spectral evolution model to include the energy diffusion, i.e., the stochastic acceleration, and apply the model to the Crab Nebula. A fairly simple form of the energy diffusion coefficient is assumed for this demonstrative study. For a particle injection to the stochastic acceleration process, we consider the continuous injection from the supernova ejecta or the impulsive injection associated with supernova explosion. The observed broadband spectrum and the decay of the radio flux are reproduced by tuning the amount of the particle injected to the stochastic acceleration process. The acceleration timescale and the duration of the acceleration are required to be a few decades and a few hundred years, respectively. Our results imply that some unveiled mechanisms, such as back reaction to the turbulence, are required to make the energies of stochastically and shock-accelerated particles comparable.

The peculiarities of particle dynamics in the Fermi acceleration scheme

International Nuclear Information System (INIS)

Buts, V.A.

2015-01-01

With examples of discrete and distributed mathematical models of the Fermi acceleration mechanism, a usefulness, or even necessity, of taking into account of singular solutions is demonstrated. Also the role is shown of those parts of phase space where the uniqueness theorem conditions to form the dynamics of physical systems are broken. It was found that the dynamics of particles in discrete and distributed mathematical schemes of Fermi acceleration can be significantly different. The difference is due to the fact that the distributed model takes into account the effects of phase space where conditions do not correspond to those necessary for application of the uniqueness theorem. The role of singular solutions is under discussion as well.

Infinite stochastic acceleration of charged particles from non-relativistic initial energies

International Nuclear Information System (INIS)

Buts, V.A.; Manujlenko, O.V.; Turkin, Yu.A.

1997-01-01

Stochastic charged particle acceleration by electro-magnetic field due to overlapping of non-linear cyclotron resonances is considered. It was shown that non-relativistic charged particles are involved in infinitive stochastic acceleration regime. This effect can be used for stochastic acceleration or for plasma heating by regular electro-magnetic fields

Particle acceleration in relativistic magnetic flux-merging events

Science.gov (United States)

Lyutikov, Maxim; Sironi, Lorenzo; Komissarov, Serguei S.; Porth, Oliver

2017-12-01

Using analytical and numerical methods (fluid and particle-in-cell simulations) we study a number of model problems involving merger of magnetic flux tubes in relativistic magnetically dominated plasma. Mergers of current-carrying flux tubes (exemplified by the two-dimensional `ABC' structures) and zero-total-current magnetic flux tubes are considered. In all cases regimes of spontaneous and driven evolution are investigated. We identify two stages of particle acceleration during flux mergers: (i) fast explosive prompt X-point collapse and (ii) ensuing island merger. The fastest acceleration occurs during the initial catastrophic X-point collapse, with the reconnection electric field of the order of the magnetic field. During the X-point collapse, particles are accelerated by charge-starved electric fields, which can reach (and even exceed) values of the local magnetic field. The explosive stage of reconnection produces non-thermal power-law tails with slopes that depend on the average magnetization . For plasma magnetization 2$ the spectrum power-law index is 2$ ; in this case the maximal energy depends linearly on the size of the reconnecting islands. For higher magnetization, 2$ , the spectra are hard, , yet the maximal energy \\text{max}$ can still exceed the average magnetic energy per particle, , by orders of magnitude (if is not too close to unity). The X-point collapse stage is followed by magnetic island merger that dissipates a large fraction of the initial magnetic energy in a regime of forced magnetic reconnection, further accelerating the particles, but proceeds at a slower reconnection rate.

The particle accelerator; L'accelerateur de particules

Energy Technology Data Exchange (ETDEWEB)

Fadel, K. [Palais de la Decouverte, Dept. de Physique, 75 - Paris (France)

2011-01-15

As the Palais de la Decouverte (in Paris) is the sole scientific vulgarization establishment in the world to operate an actual particle accelerator able to provoke different types of nuclear reactions, the author recalls some historical aspects of the concerned department since the creation of the 'Radioactivity - Atom synthesis' department in 1937. He recalls the experiments which were then performed, the installation of the particle accelerator in 1964 and its renewal. He describes what's going on in this accelerator. He gives an overview of the difficulties faced after it has been decided to move it, of the works which had to be performed, and of radiation protection measures

Dosimetry and monitoring of thin X-ray beam produced by linear particle accelerator, for application in radiography

International Nuclear Information System (INIS)

Campos, J.C.F. de.

1986-01-01

The dosimetry and monitoring characteristics of thin X-ray beams, and the application of 4MeV linear particle accelerator to radiosurgery are studied. An addition collimation system, consisted of 3 lead collimators, which allows to obtain thin beams of 6,10 and 15 mm of diameter, was fabricated. The stereo taxic system, together with modifications in dispositives, provide the accuracy required in volum-targed location. The dosimetric informations were determined with silicon detector inserted into water simulator. The isodose curves for each beam, and total isodoses simulating the treatment were established using radiographic emulsions in conditions which reproduce real circunstances of pacient irradiation. (M.C.K.) [pt

Magazine for handling stripping foils in a particle accelerator

International Nuclear Information System (INIS)

Gorka, A.J. Jr.

1975-01-01

Thin foils for stripping a particle beam are stored in a magazine that is operable remotely to display an individual foil, release it when it is spent, and repeat this process. The magazine is operable in the high-vacuum, high-radiation environment in the interior of a particle accelerator, and it uses the magnetic field of the accelerator to operate the display and dropping mechanism. (U.S.)

Lauch of CERN particle accelerator delayed

CERN Multimedia

2007-01-01

"Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inSwitzerland yesterday confirmed a delay in tests of its massive new particle accelerator." (1 page)

Experimental studies of particle acceleration with ultra-intense lasers - Applications to nuclear physics experiments involving laser-produced plasmas

International Nuclear Information System (INIS)

Plaisir, C.

2010-11-01

For the last ten years, the Ultra High Intensity Lasers offer the opportunity to produce accelerated particle beams which contain more than 10 12 electrons, protons accelerated into a few ps. We have simulated and developed some diagnostics based on nuclear activation to characterize both the angular and the energy distributions of the particle beams produced with intense lasers. The characterization methods which are presented are illustrated by means of results obtained in different experiments. We would use the particle beams produced to excite nuclear state in a plasma environment. It can modify intrinsic characteristics of the nuclei such as the half-life of some isomeric states. To prepare this kind of experiments, we have measured the nuclear reaction cross section (gamma,n) to produce the isomeric state of the 84 Rb, which has an excitation energy of 463 keV, with the electron accelerator ELSA of CEA/DIF in Bruyeres-le-Chatel (France). (author)

AI systems approach in particle accelerators

International Nuclear Information System (INIS)

Kataria, S.K.; Bhagwat, P.V.; Kori, S.A.

1992-01-01

The large particle accelerators machines like pelletron accelerator at Tata Institute of Fundamental Research (T.I.F.R) have several levels of controls with operators responsible for overall global control decisions and closed loop feedback controllers for relatively small subsystems of the machines. As the accelerator machines are becoming more complicated and the requirements more stringent, there is a need to provide the operators with an artificial intelligence (AI) system to aid in the tuning the machine and in failure diagnosis. There are few major areas in the pelletron operation, which can be done more efficiently using AI systems approach so that useful beam is available for much more time: 1) Accelerator Conditioning, 2) Accelerator Tuning, and 3) Maintaining the Tune beams. The feasibility study for using expert system for above areas and also for safety evaluation of the various subsystems is carried out. (author). 10 refs., 4 figs

Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

Science.gov (United States)

Danby, Gordon T.; Jackson, John W.

1991-01-01

A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.

Particle Acceleration, Magnetic Field Generation, and Emission in Relativistic Shocks

Science.gov (United States)

Nishikawa, Ken-IchiI.; Hededal, C.; Hardee, P.; Richardson, G.; Preece, R.; Sol, H.; Fishman, G.

2004-01-01

Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (m) code, we have investigated particle acceleration associated with a relativistic jet front propagating through an ambient plasma with and without initial magnetic fields. We find only small differences in the results between no ambient and weak ambient parallel magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates particles perpendicular and parallel to the jet propagation direction. New simulations with an ambient perpendicular magnetic field show the strong interaction between the relativistic jet and the magnetic fields. The magnetic fields are piled up by the jet and the jet electrons are bent, which creates currents and displacement currents. At the nonlinear stage, the magnetic fields are reversed by the current and the reconnection may take place. Due to these dynamics the jet and ambient electron are strongly accelerated in both parallel and perpendicular directions.

Criteria of classification applied to licensing of particle accelerators

International Nuclear Information System (INIS)

Costa, Evaldo L.C.; Melo, Paulo F.F.

2013-01-01

This work aims to bring to discussion the proposal of a new classification model toward to generating ionizing radiation, specifically particle accelerators, considering two parameters: the size of these facilities and the level of energy they operate, emphasizing large accelerators, which typically operate at higher levels of energy. Also motivated by the fact that the Brazilian rules do not provide an adequate standard of licensing for this size of installation, this work will seek to revise the existing classification, where generators of ionizing radiation (including particle accelerators) are considered up to the level of energy of 50 MeV

Applications of the second-order achromat concept to the design of particle accelerators

International Nuclear Information System (INIS)

Brown, K.L.; Servranckx, R.V.

1985-05-01

A property of the second-order achromat, whereby dipole and sextupole families may be inserted into a lattice for chromatic corrections without introducing second-order geometrical (on momentum) optical distortions, has been incorporated in several new particle accelerator designs. These include the SLC at SLAC, LEP at CERN, the EROS pulse stretcher ring at Saskatoon, the CEBAF ring at SURA, and the MIT ring

THE EFFECT OF COOLING ON PARTICLE TRAJECTORIES AND ACCELERATION IN RELATIVISTIC MAGNETIC RECONNECTION

Energy Technology Data Exchange (ETDEWEB)

Kagan, Daniel; Nakar, Ehud [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Piran, Tsvi, E-mail: daniel.kagan@mail.huji.ac.il [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)

2016-12-20

The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region with and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle during acceleration. Using the calculated distribution of this average magnetic field as a function of uncooled final particle energy, we find analytically that cooling does not affect power-law particle energy spectra except at energies far above the synchrotron burnoff limit. Finally, we compare fully cooled and uncooled simulations of reconnection, confirming that the synchrotron burnoff limit does not produce a cutoff in the particle energy spectrum. Our results indicate that the TPC method accurately predicts the effects of cooling on particle acceleration in relativistic reconnection, and that, even far above the burnoff limit, the synchrotron energy of radiation produced in reconnection is not limited by cooling.

THE EFFECT OF COOLING ON PARTICLE TRAJECTORIES AND ACCELERATION IN RELATIVISTIC MAGNETIC RECONNECTION

International Nuclear Information System (INIS)

Kagan, Daniel; Nakar, Ehud; Piran, Tsvi

2016-01-01

The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region with and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle during acceleration. Using the calculated distribution of this average magnetic field as a function of uncooled final particle energy, we find analytically that cooling does not affect power-law particle energy spectra except at energies far above the synchrotron burnoff limit. Finally, we compare fully cooled and uncooled simulations of reconnection, confirming that the synchrotron burnoff limit does not produce a cutoff in the particle energy spectrum. Our results indicate that the TPC method accurately predicts the effects of cooling on particle acceleration in relativistic reconnection, and that, even far above the burnoff limit, the synchrotron energy of radiation produced in reconnection is not limited by cooling.

Radiological protection at particle accelerators: An overview

International Nuclear Information System (INIS)

Thomas, R.H.

1991-01-01

Radiological protection began with particle accelerators. Many of the concerns in the health physics profession today were discovered at accelerator laboratories. Since the mid-1940s, our understanding has progressed through seven stages: observation of high radiation levels; shielding; development of dosimetric techniques; studies of induced activity and environmental impact; legislative and regulatory concerns; and disposal. The technical and scientific aspects of accelerator radiation safety are well in hand. In the US, there is an urgent need to move away from a ''best available technology'' philosophy to risk-based health protection standards. The newer accelerators will present interesting radiological protection issues, including copious muon production and high LET (neutron) environments

Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets

Science.gov (United States)

Nishikawa, K.-I.; Hardee, P.; Hededal, C.; Mizuno, Yosuke; Fishman, G. Jerry; Hartmann, D. H.

2006-01-01

Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma-ray bursts (GRBs), supernova remnants, and Galactic microquasar systems usually have power-law emission spectra. Fermi acceleration is the mechanism usually assumed for the acceleration of particles in astrophysical environments. Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets show that particle acceleration occurs within the downstream jet, rather than by the scattering of particles back and forth across the shock as in Fermi acceleration. Shock acceleration' is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different spectral properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants. We will review recent PIC simulations of relativistic jets and try to make a connection with observations.

An Examination of Resonance, Acceleration, and Particle Dynamics in the Micro-Accelerator Platform

International Nuclear Information System (INIS)

McNeur, Josh; Rosenzweig, J. B.; Travish, G.; Zhou, J.; Yoder, R.

2010-01-01

An effort to build a micron-scale dielectric-based slab-symmetric accelerator is underway at UCLA. The structure achieves acceleration via a resonant accelerating mode that is excited in an approximately 800 nm wide vacuum gap by a side coupled 800 nm laser. Detailed simulation results on structure fields and particle dynamics, using HFSS and VORPAL, are presented. We examine the quality factors of the accelerating modes for various structures and the excitations of non-accelerating destructive modes. Additionally, the results of an analytic and computational study of focusing, longitudinal dynamics and acceleration are described. Methods for achieving simultaneous transverse and longitudinal focusing are discussed, including modification of structure dimensions and slow variation of the coupling periodicity.

Physics of the saturation of particle acceleration in relativistic magnetic reconnection

Science.gov (United States)

Kagan, Daniel; Nakar, Ehud; Piran, Tsvi

2018-05-01

We investigate the saturation of particle acceleration in relativistic reconnection using two-dimensional particle-in-cell simulations at various magnetizations σ. We find that the particle energy spectrum produced in reconnection quickly saturates as a hard power law that cuts off at γ ≈ 4σ, confirming previous work. Using particle tracing, we find that particle acceleration by the reconnection electric field in X-points determines the shape of the particle energy spectrum. By analysing the current sheet structure, we show that physical cause of saturation is the spontaneous formation of secondary magnetic islands that can disrupt particle acceleration. By comparing the size of acceleration regions to the typical distance between disruptive islands, we show that the maximum Lorentz factor produced in reconnection is γ ≈ 5σ, which is very close to what we find in our particle energy spectra. We also show that the dynamic range in Lorentz factor of the power-law spectrum in reconnection is ≤40. The hardness of the power law combined with its narrow dynamic range implies that relativistic reconnection is capable of producing the hard narrow-band flares observed in the Crab nebula but has difficulty producing the softer broad-band prompt gamma-ray burst emission.

Special issue - Applying the accelerator

International Nuclear Information System (INIS)

Anon.

1995-01-01

T'he CERN Courier is the international journal of high energy physics, covering current developments in and around this branch of basic science. A recurrent theme is applying the technology developed for particle accelerators, the machines which produce beams of high energy particles for physics experiments. Twentieth-century science is full of similar examples of applications derived from pure research. This special issue of the CERN Courier is given over to one theme - the applications of accelerators. Accelerator systems and facilities are normally associated with highenergy particle physics research, the search for fundamental particles and the quest to understand the physics of the Big Bang. To the layman, accelerator technology has become synonymous with large and expensive machines, exploiting the most modern technology for basic research. In reality, the range of accelerators and their applications is much broader. A vast number of accelerators, usually much smaller and operating for specific applications, create wealth and directly benefit the population, particularly in the important areas of healthcare, energy and the environment. There are well established applications in diagnostic and therapeutic medicine for research and routine clinical treatments. Accelerators and associated technologies are widely employed by industry for manufacturing and process control. In fundamental and applied research, accelerator systems are frequently used as tools. The biennial conference on the Applications of Accelerators in Industry and Research at Denton, Texas, attracts a thousand participants. This special issue of the CERN Courier includes articles on major applications, reflecting the diversity and value of accelerator technology. Under Guest Editor Dewi Lewis of Amersham International, contributions from leading international specialists with experience of the application end of the accelerator chain describe their fields of direct interest. The

Special issue - Applying the accelerator

Energy Technology Data Exchange (ETDEWEB)

Anon.

1995-07-15

T'he CERN Courier is the international journal of high energy physics, covering current developments in and around this branch of basic science. A recurrent theme is applying the technology developed for particle accelerators, the machines which produce beams of high energy particles for physics experiments. Twentieth-century science is full of similar examples of applications derived from pure research. This special issue of the CERN Courier is given over to one theme - the applications of accelerators. Accelerator systems and facilities are normally associated with highenergy particle physics research, the search for fundamental particles and the quest to understand the physics of the Big Bang. To the layman, accelerator technology has become synonymous with large and expensive machines, exploiting the most modern technology for basic research. In reality, the range of accelerators and their applications is much broader. A vast number of accelerators, usually much smaller and operating for specific applications, create wealth and directly benefit the population, particularly in the important areas of healthcare, energy and the environment. There are well established applications in diagnostic and therapeutic medicine for research and routine clinical treatments. Accelerators and associated technologies are widely employed by industry for manufacturing and process control. In fundamental and applied research, accelerator systems are frequently used as tools. The biennial conference on the Applications of Accelerators in Industry and Research at Denton, Texas, attracts a thousand participants. This special issue of the CERN Courier includes articles on major applications, reflecting the diversity and value of accelerator technology. Under Guest Editor Dewi Lewis of Amersham International, contributions from leading international specialists with experience of the application end of the accelerator chain describe their fields of direct interest. The contributions

Engines of discovery a century of particle accelerators

CERN Document Server

Sessler, Andrew

2014-01-01

Particle accelerators exploit the cutting edge of every aspect of today's technology and have themselves contributed to many of these technologies. The largest accelerators have been constructed as research tools for nuclear and high energy physics and there is no doubt that it is this field that has sustained their development culminating in the Large Hadron Collider. An earlier book by the same authors, Engines of Discovery: A Century of Particle Accelerators chronicled the development of these large accelerators and colliders, emphasizing the critical discoveries in applied physics and engineering that drove the field. Particular attention was given to the key individuals who contributed, the methods they used to arrive at their particular discoveries and inventions, often recalling how their human strengths and attitudes may have contributed to their achievements. Much of this historical picture is also to be found, little changed, in Part A of this sequel. Since the first book was written it has become ...

Can Substorm Particle Acceleration Be Applied to Solar Flares?

Energy Technology Data Exchange (ETDEWEB)

Birn, J. [Space Science Institute, Boulder, CO 80301 (United States); Battaglia, M. [Institute of 4D Technologies, School of Engineering, University of Applied Sciences and Arts Northwestern Switzerland, CH-5210 Windisch (Switzerland); Fletcher, L. [University of Glasgow, Scotland (United Kingdom); Hesse, M. [Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, NO-5007 Bergen (Norway); Neukirch, T., E-mail: jbirn@lanl.gov [University of St. Andrews, Scotland (United Kingdom)

2017-10-20

Using test particle studies in the electromagnetic fields of three-dimensional magnetohydrodynamic (MHD) simulations of magnetic reconnection, we study the energization of charged particles in the context of the standard two-ribbon flare picture in analogy to the standard magnetospheric substorm paradigm. In particular, we investigate the effects of the collapsing field (“collapsing magnetic trap”) below a reconnection site, which has been demonstrated to be the major acceleration mechanism that causes energetic particle acceleration and injections observed in Earth’s magnetotail associated with substorms and other impulsive events. We contrast an initially force-free, high-shear field (low beta) with low and moderate shear, finite-pressure (high-beta) arcade structures, where beta represents the ratio between gas (plasma) and magnetic pressure. We demonstrate that the energization affects large numbers of particles, but the acceleration is modest in the presence of a significant shear field. Without incorporating loss mechanisms, the effect on particles at different energies is similar, akin to adiabatic heating, and thus is not a likely mechanism to generate a power-law tail onto a (heated or not heated) Maxwellian velocity distribution.

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

International Nuclear Information System (INIS)

Maschke, A. W.

1985-01-01

A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow throughout the assembly

Theses of XX International Seminar on charged particle accelerators

International Nuclear Information System (INIS)

Papkovich, V.G.; Rakivnenko, L.M.

2007-01-01

Published abstracts of reports of the XX International Seminar on charged particle accelerators have interest for specialists in the fields of linear accelerator physics and technology, VHF uses systems of beam diagnostics and autometed control, new acceleration methods and for theses who use electrophysical devices in industry, medicine and research

Test Particles with Acceleration-Dependent Lagrangian

OpenAIRE

Toller, M.

2005-01-01

We consider a classical test particle subject to electromagnetic and gravitational fields, described by a Lagrangian depending on the acceleration and on a fundamental length. We associate to the particle a moving local reference frame and we study its trajectory in the principal fibre bundle of all the Lorentz frames. We discuss in this framework the general form of the Lagrange equations and the connection between symmetries and conservation laws (Noether theorem). We apply these results to...

Theses of XIX International Seminar on charged particle accelerators

International Nuclear Information System (INIS)

Anon

2005-01-01

Published abstracts of reports of the XIX International Seminar on charged particle accelerators have interest for specialists in the fields of linear accelerator physics and technology, VHF uses, systems of beam diagnostics and automated control, new acceleration methods, as well as for theses who use electrophysical devices in industry, medicine and research

The design and performance of Static Var Compensators for particle accelerators

CERN Document Server

Kahle, Karsten; Genton, Charles-Mathieu

2015-01-01

Particle accelerators, and in particular synchrotrons, represent large cycling non-linear loads connected to the electrical distribution network. This paper discusses the typical design and performance of Static Var Compensators (SVCs) to obtain the excellent power quality levels required for particle accelerator operation.

Particle accelerator physics and technology for high energy density physics research

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, D.H.H.; Blazevic, A.; Rosmej, O.N.; Spiller, P.; Tahir, N.A.; Weyrich, K. [Gesellschaft fur Schwerionenforschung, GSI-Darmstadt, Plasmaphysik, Darmstadt (Germany); Hoffmann, D.H.H.; Dafni, T.; Kuster, M.; Ni, P.; Roth, M.; Udrea, S.; Varentsov, D. [Darmstadt Univ., Institut fur Kernphysik, Technische Schlobgartenstr. 9 (Germany); Jacoby, J. [Frankfurt Univ., Institut fur Angewandte Physik (Germany); Kain, V.; Schmidt, R.; Zioutas, K. [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Zioutas, K. [Patras Univ., Dept. of Physics (Greece); Mintsev, V.; Fortov, V.E. [Russian Academy of Sciences, Institute of Problems of Chemical Physics, Chernogolovka (Russian Federation); Sharkov, B.Y. [Institut for Theoretical and Experimental Physics ITEP, Moscow (Russian Federation)

2007-08-15

Interaction phenomena of intense ion- and laser radiation with matter have a large range of application in different fields of science, extending from basic research of plasma properties to applications in energy science, especially in inertial fusion. The heavy ion synchrotron at GSI now routinely delivers intense uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Our simulations show that the new accelerator complex FAIR (Facility for Antiproton and Ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. A natural example of hot dense plasma is provided by our neighbouring star the sun, and allows a deep insight into the physics of fusion, the properties of matter at high energy density, and is moreover an excellent laboratory for astro-particle physics. As such the sun's interior plasma can even be used to probe the existence of novel particles and dark matter candidates. We present an overview on recent results and developments of dense plasma physics addressed with heavy ion and laser beams combined with accelerator- and nuclear physics technology. (authors)

Studies on mechanisms of the laser particle acceleration

International Nuclear Information System (INIS)

Aurand, Bastian

2012-01-01

Within the last decade, many developments towards higher energies and particle numbers paved the way of particle acceleration performed by high intensity laser systems. Up to now, the process of a field-induced acceleration process (Target-Normal-Sheath-Acceleration (TNSA)) is investigated the most. Acceleration occurs as a consequence of separation of charges on a surface potential. Here, the broad energy spectrum is a problem not yet overcome although many improvements were achieved. Calculations for intensities higher than 10 20..21 W/cm 2 give hint that Radiation-Pressure-Acceleration (RPA) may lead to a sharper, monoenergetic energy spectrum. Within the framework of this thesis, the investigation of the acceleration mechanism is studied experimentally in the intensity range of 10 19 W/cm 2 . Suitable targets were developed and applied for patent. A broad range of parameters was scanned by means of high repetition rates together with an adequate laser system to provide high statistics of several thousands of shots, and the dependence of target material, intensity, laser polarisation and pre plasma-conditions was verified. Comparisons with 2-d numeric simulations lead to a model of the acceleration process which was analyzed by several diagnostic methods, giving clear evidence for a new, not field-induced acceleration process. In addition, a system for a continuous variation of the polarization based on reflective optics was developed in order to overcome the disadvantages of retardation plates, and their practicability of high laser energies can be achieved.

Charged particle and photon acceleration by wakefield plasma waves in non-uniform plasmas

International Nuclear Information System (INIS)

Bulanov, S.V.; Kirsanov, V.I.; Sakharov, A.S.; Pegoraro, F.

1993-01-01

We discuss the acceleration of charged particles and the upshift of the frequency of short wave packets of laser radiation. The acceleration and the upshift are caused by wake plasma waves excited by a strong laser pulse in a non-uniform plasma. We show that unlimited acceleration of charged particles is possible for specific spatial dependencies of the plasma density. In this unlimited acceleration regime, particles have a fixed phase relationship with respect to the plasma wave, while their energy increases with time. When the wave breaking limit is approached and surpassed, the efficiency of the acceleration of the charged particles and of the frequency upshift of the photons can be increased significantly. (author) 3 refs

Monte Carlo method implemented in a finite element code with application to dynamic vacuum in particle accelerators

CERN Document Server

Garion, C

2009-01-01

Modern particle accelerators require UHV conditions during their operation. In the accelerating cavities, breakdowns can occur, releasing large amount of gas into the vacuum chamber. To determine the pressure profile along the cavity as a function of time, the time-dependent behaviour of the gas has to be simulated. To do that, it is useful to apply accurate three-dimensional method, such as Test Particles Monte Carlo. In this paper, a time-dependent Test Particles Monte Carlo is used. It has been implemented in a Finite Element code, CASTEM. The principle is to track a sample of molecules during time. The complex geometry of the cavities can be created either in the FE code or in a CAD software (CATIA in our case). The interface between the two softwares to export the geometry from CATIA to CASTEM is given. The algorithm of particle tracking for collisionless flow in the FE code is shown. Thermal outgassing, pumping surfaces and electron and/or ion stimulated desorption can all be generated as well as differ...

EPAC impact (European Particle Accelerator Conference report)

International Nuclear Information System (INIS)

Clarke, Jim

1994-01-01

Acurtain rose on the current world accelerator stage at the end of June when almost 750 delegates gathered in London for the fourth biennial European Particle Accelerator Conference (EPAC). As well as reports from all major Laboratories on their latest accelerator achievements and future plans, a special session featured invited contributions on high intensity issues while a seminar covered the increasing transfer of technology between Accelerator Laboratories and Industry. The first invited talk of the conference, by CERN Director General Chris Llewellyn Smith, concerned the future of high energy physics in Europe. Naturally this focused on the Large Hadron Collider project at CERN, which will open up important new physics frontiers for the 21st century

Particle acceleration by Alfven wave turbulence in radio galaxies

International Nuclear Information System (INIS)

Eilek, J.A.

1986-01-01

Radio galaxies show evidence for acceleration of relativistic electrons locally within the diffuse radio luminous plasma. One likely candidate for the reacceleration mechanism is acceleration by magnetohydrodynamic turbulence which exists within the plasma. If Alfven waves are generated by a fluid turbulent cascade described by a power law energy-wavenumber spectrum, the particle spectrum in the presence of synchrotron losses will evolve towards an asymptotic power law which agrees with the particle spectra observed in these sources

Scale-by-scale contributions to Lagrangian particle acceleration

Science.gov (United States)

Lalescu, Cristian C.; Wilczek, Michael

2017-11-01

Fluctuations on a wide range of scales in both space and time are characteristic of turbulence. Lagrangian particles, advected by the flow, probe these fluctuations along their trajectories. In an effort to isolate the influence of the different scales on Lagrangian statistics, we employ direct numerical simulations (DNS) combined with a filtering approach. Specifically, we study the acceleration statistics of tracers advected in filtered fields to characterize the smallest temporal scales of the flow. Emphasis is put on the acceleration variance as a function of filter scale, along with the scaling properties of the relevant terms of the Navier-Stokes equations. We furthermore discuss scaling ranges for higher-order moments of the tracer acceleration, as well as the influence of the choice of filter on the results. Starting from the Lagrangian tracer acceleration as the short time limit of the Lagrangian velocity increment, we also quantify the influence of filtering on Lagrangian intermittency. Our work complements existing experimental results on intermittency and accelerations of finite-sized, neutrally-buoyant particles: for the passive tracers used in our DNS, feedback effects are neglected such that the spatial averaging effect is cleanly isolated.

Current-voltage relationship in the auroral particle acceleration region

Directory of Open Access Journals (Sweden)

M. Morooka

2004-11-01

Full Text Available The current-voltage relationship in the auroral particle acceleration region has been studied statistically by the Akebono (EXOS-D satellite in terms of the charge carriers of the upward field-aligned current. The Akebono satellite often observed field-aligned currents which were significantly larger than the model value predicted by Knight (1973. We compared the upward field-aligned current estimated by three different methods, and found that low-energy electrons often play an important role as additional current carriers, together with the high-energy primary electrons which are expected from Knight's relation. Such additional currents have been observed especially at high and middle altitudes of the particle acceleration region. Some particular features of electron distribution functions, such as "cylindrical distribution functions" and "electron conics", have often been observed coinciding with the additional currents. They indicated time variability of the particle acceleration region. Therefore, we have concluded that the low-energy electrons within the "forbidden" region of electron phase space in the stationary model often contribute to charge carriers of the current because of the rapid time variability of the particle acceleration region. "Cylindrical distribution functions" are expected to be found below the time-varying potential difference. We statistically examined the locations of "cylindrical distribution function", and found that their altitudes are related to the location where the additional currents have been observed. This result is consistent with the idea that the low-energy electrons can also carry significant current when the acceleration region changes in time.

AXEL-2016: Introduction to Particle Accelerators

CERN Multimedia

2016-01-01

AXEL-2016 is the latest in a yearly lecture series on particle accelerators given at CERN within the framework of the 2016 Technical Training Programme. As part of the BE department's Operation group’s shutdown lecture series, this general accelerator physics module has been offered since 2003 as a joint venture between the BE department and the Technical Training team and is open to the wider CERN community.    The lecturer is Rende Steerenberg, deputy leader of the Operation group and PS section leader. Programme: basic mathematics; transverse optics; lattice calculations; resonances; longitudinal motion; transfer lines, injection and ejection; longitudinal and transverse beam instabilities; colliders. A detailed programme is available on the AXEL-2016 webpage. Target audience: designed for technicians who are operating an accelerator or whose work is closely linked to accelerators, but also open to technicians, engineers and physicists interested i...

Effect of polarization and focusing on laser pulse driven auto-resonant particle acceleration

International Nuclear Information System (INIS)

Sagar, Vikram; Sengupta, Sudip; Kaw, Predhiman

2014-01-01

The effect of laser polarization and focusing is theoretically studied on the final energy gain of a particle in the Auto-resonant acceleration scheme using a finite duration laser pulse with Gaussian shaped temporal envelope. The exact expressions for dynamical variables viz. position, momentum, and energy are obtained by analytically solving the relativistic equation of motion describing particle dynamics in the combined field of an elliptically polarized finite duration pulse and homogeneous static axial magnetic field. From the solutions, it is shown that for a given set of laser parameters viz. intensity and pulse length along with static magnetic field, the energy gain by a positively charged particle is maximum for a right circularly polarized laser pulse. Further, a new scheme is proposed for particle acceleration by subjecting it to the combined field of a focused finite duration laser pulse and static axial magnetic field. In this scheme, the particle is initially accelerated by the focused laser field, which drives the non-resonant particle to second stage of acceleration by cyclotron Auto-resonance. The new scheme is found to be efficient over two individual schemes, i.e., auto-resonant acceleration and direct acceleration by focused laser field, as significant particle acceleration can be achieved at one order lesser values of static axial magnetic field and laser intensity

Plasma jet acceleration of dust particles to hypervelocities

International Nuclear Information System (INIS)

Ticos, C. M.; Wang, Zhehui; Wurden, G. A.; Kline, J. L.; Montgomery, D. S.

2008-01-01

A convenient method to accelerate simultaneously hundreds of micron-size dust particles to a few km/s over a distance of about 1 m is based on plasma drag. Plasma jets which can deliver sufficient momentum to the dust particles need to have speeds of at least several tens of km/s, densities of the order of 10 22 m -3 or higher, and low temperature ∼1 eV, in order to prevent dust destruction. An experimental demonstration of dust particles acceleration to hypervelocities by plasma produced in a coaxial gun is presented here. The plasma flow speed is deduced from photodiode signals while the plasma density is measured by streaked spectroscopy. As a result of the interaction with the plasma jet, the dust grains are also heated to high temperatures and emit visible light. A hypervelocity dust shower is imaged in situ with a high speed video camera at some distance from the coaxial gun, where light emission from the plasma flow is less intense. The bright traces of the flying microparticles are used to infer their speed and acceleration by employing the time-of-flight technique. A simple model for plasma drag which accounts for ion collection on the grain surface gives predictions for dust accelerations which are in good agreement with the experimental observations.

Accelerators: the large slings of small particles

International Nuclear Information System (INIS)

Crozon, M.

1987-01-01

This paper reviews the different types of accelerators, of particles or heavy ions, which have been developed or are in project, their performance, their limits, which noting briefly the technologies used [fr

Radiation protection for particle accelerators

International Nuclear Information System (INIS)

Verdu, G.; Rodenas, J.; Campayo, J.M.

1992-01-01

It a a great number of medical installations in spain using particle accelerators for radiotherapy. It is obvious the importance of an accurate estimation of the doses produced in these installations that may be received by health workers, patients or public. The lower values of dose limits established in the new ICRP recommendations imply a recalculation of items concerning such installations. In our country, specific guidelines for radiation protection in particle accelerators facilities have not been yet developed, however two possible guides can be used, NCRP report number 51 and DIN Standard 6847. Both have been analyzed comparatively in the paper, and major remarks have been summarized. Interest has been focused on thickness estimation of shielding barriers in order to verify whether must be modified to comply with the new dose limits. Primary and secondary barriers for a Mevatron used in a Medical Center, have been calculated and the results have been compared with actual data obtained from the installation, to test the adequacy of shielding barriers and radioprotection policies. The results obtained are presented and analyzed in order to state the implications of the new ICRP recommendations. (author)

Particle Accelerators for PET radionuclides

DEFF Research Database (Denmark)

Jensen, Mikael

2012-01-01

The requirements set for particle accelerators for production of radioactive isotopes for PET can easily be derived from first principles. The simple general need is for proton beams with energy in the region 10–20 MeV and current 20–100 microAmps. This is most reliably and cost-effectively achie......The requirements set for particle accelerators for production of radioactive isotopes for PET can easily be derived from first principles. The simple general need is for proton beams with energy in the region 10–20 MeV and current 20–100 microAmps. This is most reliably and cost......-effectively achieved by the well proven technology of the compact medical cyclotron, presently available from several companies. The main features of these cyclotrons are essential similar: resistive, sector focused iron magnets, internal negative ion sources and stripping extraction. The remaining differences between...... different manufacturers will be discussed the light of what is actually needed for a given PET site operation. Alternatives to the conventional cyclotron have been proposed and tested but have at present very limited use. These alternatives will be discussed, as well as the future possibilities of supplying...

Design of MgB2 superconducting dipole magnet for particle beam transport in accelerators

DEFF Research Database (Denmark)

Abrahamsen, A.B.; Zangenberg, N.; Baurichter, A.

2006-01-01

for the collaborating company Danfysik A/S, which has a strongtradition in building resistive magnets for particle accelerators[4]. A technology transfer project was formulated at the end of 2005 with the purpose to collect the knowledge about the MgB2 superconductor gained in the STVF program and in the European...... in a dipole magnet for guiding particle beams in a small scale accelerator is examined with the purpose to build lighter and smaller than the present resistive magnets. Here the criticalcurrent density of primarily MgB2 will be compared with current density determined by specifications similar to the Tevatron...... accelerator, B = 4:4 Tesla and coil aperture D = 76 mm [6], which has been identified by Danfysik A/S as interesting. It isconcluded that MgB2 is useful for the dipole application and construction of a small test coil of one half of the magnet is planned in 2007....

AXEL–2014: Introduction to Particle Accelerators

CERN Multimedia

2014-01-01

AXEL-2014 is a series of courses on particle accelerators, given at CERN within the framework of the 2014 Technical Training Program. As part of the BE Department’s Operation Group Shutdown Lecture series, the general accelerator physics module has been organised since 2003 as a joint venture between the BE Department and Technical Training, and is open to the wider CERN community.   The AXEL-2014 course series is designed for technicians who are operating an accelerator or whose work is closely linked to accelerators, but it is also open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge of accelerators. However, some basic knowledge of trigonometry, matrices and differential equations, and some basic knowledge of magnetism would be an advantage. The series will be composed of 10 modules (Monday 24 March 2014 – Fri 28 March 2014, from 9 a.m. to 10:15 a.m. and from 10:45 a.m. to 12 noon), and will be given in En...

STOCHASTIC PARTICLE ACCELERATION IN TURBULENCE GENERATED BY MAGNETOROTATIONAL INSTABILITY

Energy Technology Data Exchange (ETDEWEB)

Kimura, Shigeo S.; Toma, Kenji [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578 (Japan); Suzuki, Takeru K.; Inutsuka, Shu-ichiro, E-mail: shigeo@astr.tohoku.ac.jp [Department of Physics, Nagoya University, Nagoya, Aichi 464-8602 (Japan)

2016-05-10

We investigate stochastic particle acceleration in accretion flows. It is believed that magnetorotational instability (MRI) generates turbulence inside accretion flows and that cosmic rays (CRs) are accelerated by the turbulence. We calculate equations of motion for CRs in the turbulent fields generated by MRI with the shearing box approximation and without back reaction to the field. Our results show that the CRs randomly gain or lose their energy through interaction with the turbulent fields. The CRs diffuse in the configuration space anisotropically: the diffusion coefficient in the direction of the unperturbed flow is about 20 times higher than the Bohm coefficient, while those in the other directions are only a few times higher than the Bohm. The momentum distribution is isotropic and its evolution can be described by the diffusion equation in momentum space where the diffusion coefficient is a power-law function of the CR momentum. We show that the shear acceleration works efficiently for energetic particles. We also cautiously note that in the shearing box approximation, particles that cross the simulation box many times along the radial direction undergo unphysical runaway acceleration by the Lorentz transformation, which needs to be taken into account with special care.

Advances of dense plasma physics with particle accelerators

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, D.H.H.; Blazevic, A.; Rosmej, O.N.; Spiller, P.; Tahir, N.A.; Weyrich, K. [Gesellschaft fur Schwerionenforschung, GSI-Darmstadt, Plasmaphysik, Darmstadt (Germany); Hoffmann, D.H.H.; Dafni, T.; Kuster, M.; Roth, M.; Udrea, S.; Varentsov, D. [DarmstadtTechnische Univ., Institut fur Kernphysik (Germany); Jacoby, J. [Frankfurt Univ., Institut fur Angewandte Physik (Germany); Zioutas, K. [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Patras Univ., Dept. of Physics (Greece); Sharkov, B.Y. [Institut for Theoretical and Experimental Physics ITEP, Moscow (Russian Federation)

2006-06-15

High intensity particle beams from accelerators induce high energy density states in bulk matter. The SIS-18 heavy ion synchrotron at GSI (Darmstadt, Germany) now routinely delivers intense Uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Due to the specific nature of the ion-matter interaction a volume of matter is heated uniformly with low gradients of temperature and pressure in the initial phase, depending on the pulse structure of the beam with respect to space and time. The new accelerator complex FAIR (Facility for Antiproton and ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. One special piece of accelerator equipment a superconducting high field dipole magnet, developed for the LHC at CERN is now serving as a key instrument to diagnose the dense plasma of the sun interior plasma, thus providing an extremely interesting combination of accelerator physics, plasma physics and particle physics. (authors)

Advances of dense plasma physics with particle accelerators

International Nuclear Information System (INIS)

Hoffmann, D.H.H.; Blazevic, A.; Rosmej, O.N.; Spiller, P.; Tahir, N.A.; Weyrich, K.; Hoffmann, D.H.H.; Dafni, T.; Kuster, M.; Roth, M.; Udrea, S.; Varentsov, D.; Jacoby, J.; Zioutas, K.; Sharkov, B.Y.

2006-01-01

High intensity particle beams from accelerators induce high energy density states in bulk matter. The SIS-18 heavy ion synchrotron at GSI (Darmstadt, Germany) now routinely delivers intense Uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Due to the specific nature of the ion-matter interaction a volume of matter is heated uniformly with low gradients of temperature and pressure in the initial phase, depending on the pulse structure of the beam with respect to space and time. The new accelerator complex FAIR (Facility for Antiproton and ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. One special piece of accelerator equipment a superconducting high field dipole magnet, developed for the LHC at CERN is now serving as a key instrument to diagnose the dense plasma of the sun interior plasma, thus providing an extremely interesting combination of accelerator physics, plasma physics and particle physics. (authors)

A model for particle acceleration in lower hybrid collapse

International Nuclear Information System (INIS)

Retterer, J.M.

1997-01-01

A model for particle acceleration during the nonlinear collapse of lower hybrid waves is described. Using the Musher-Sturman wave equation to describe the effects of nonlinear processes and a velocity diffusion equation for the particle velocity distribution, the model self-consistently describes the exchange of energy between the fields and the particles in the local plasma. Two-dimensional solutions are presented for the modulational instability of a plane wave and the collapse of a cylindrical wave packet. These calculations were motivated by sounding rocket observations in the vicinity of auroral arcs in the Earth close-quote s ionosphere, which have revealed the existence of large-amplitude lower-hybrid wave packets associated with ions accelerated to energies of 100 eV. The scaling of the sizes of these wave packets is consistent with the theory of lower-hybrid collapse and the observed lower-hybrid field amplitudes are adequate to accelerate the ionospheric ions to the observed energies

Hysteresis effects in the cores of particle accelerator magnets

CERN Document Server

AUTHOR|(CDS)2086181; Schoerling, Daniel

A study of the hysteresis effects in the cores of particle accelerator magnets has been performed in the framework of the work presented in this thesis. This study has been focused on normal conducting particle accelerator magnets whose cores are manufactured using ferromagnetic materials. The magnetic circuits have been modelled using the developed models: one model for the magnetic circuit and one for the magnetization of the material in the core. The parameters of the magnetic circuit model have been identified with the help of simulations which rely on the finite element method (Opera 3D), while the parameters of the magnetic hysteresis model have been identified through experimental measurements performed using a method developed in the framework of this work. The modelling results have been validated by means of experimental measurements performed on two magnets: one small size magnet which has been specifically designed and manufactured, and one magnet which is currently used in a particle accelerator ...

The acceleration and propagation of energetic particles in turbulent cosmic plasmas

International Nuclear Information System (INIS)

Achterberg, A.

1981-01-01

This thesis concentrates on the acceleration and propagation of energetic particles in turbulent cosmic plasmas. The stochastic acceleration of relativistic electrons by long-wavelength weak magnetohydrodynamic turbulence is considered and a model is discussed that allows the determination of both the electron energy spectrum and the wavenumber spectrum of the magnetohydrodynamic turbulence in a consistent way. The question of second phase acceleration in large solar flares and the precise form of the force exerted on the background plasma when Alfven waves are generated by fast particles are considered. The energy balance in the shock wave acceleration, the propagation of energetic particles in a high β plasma (β>10 2 ) and sheared flow as a possible source of plasma turbulence for a magnetized plasma with field-aligned flow, are discussed. (Auth./C.F.)

Particle acceleration and production of energetic photons in SN1987A

Energy Technology Data Exchange (ETDEWEB)

Gaisser, T.K.; Stanev, Todor; Harding, Alice

1987-09-24

Young supernova remnants are likely to be bright sources of energetic photons and neutrinos through the collision of particles accelerated inside the remnant. Interactions of accelerated particles in the expanding envelope or in ambient radiation fields will also produce secondary photons and neutrinos at some level. If > 10/sup 39/ erg s/sup -1/ in protons above 10 TeV is injected into the target region, TeV photons from SN1987A could be observable with present detectors. Synchrotron X rays and ..gamma..-rays up to 10 MeV, generated by accelerated electrons, may well also be detectable. The authors discuss a pulsar wind model for acceleration of particles, and find that it would produce observable signals if the spin period of the pulsar is <10 ms.

The Acceleration of Charged Particles at a Spherical Shock Moving through an Irregular Magnetic Field

Energy Technology Data Exchange (ETDEWEB)

Giacalone, J. [Department of Planetary Sciences, University of Arizona, Tucson, AZ (United States)

2017-10-20

We investigate the physics of charged-particle acceleration at spherical shocks moving into a uniform plasma containing a turbulent magnetic field with a uniform mean. This has applications to particle acceleration at astrophysical shocks, most notably, to supernovae blast waves. We numerically integrate the equations of motion of a large number of test protons moving under the influence of electric and magnetic fields determined from a kinematically defined plasma flow associated with a radially propagating blast wave. Distribution functions are determined from the positions and velocities of the protons. The unshocked plasma contains a magnetic field with a uniform mean and an irregular component having a Kolmogorov-like power spectrum. The field inside the blast wave is determined from Maxwell’s equations. The angle between the average magnetic field and unit normal to the shock varies with position along its surface. It is quasi-perpendicular to the unit normal near the sphere’s equator, and quasi-parallel to it near the poles. We find that the highest intensities of particles, accelerated by the shock, are at the poles of the blast wave. The particles “collect” at the poles as they approximately adhere to magnetic field lines that move poleward from their initial encounter with the shock at the equator, as the shock expands. The field lines at the poles have been connected to the shock the longest. We also find that the highest-energy protons are initially accelerated near the equator or near the quasi-perpendicular portion of the shock, where the acceleration is more rapid.

OpenFOAM Modeling of Particle Heating and Acceleration in Cold Spraying

Science.gov (United States)

Leitz, K.-H.; O'Sullivan, M.; Plankensteiner, A.; Kestler, H.; Sigl, L. S.

2018-01-01

In cold spraying, a powder material is accelerated and heated in the gas flow of a supersonic nozzle to velocities and temperatures that are sufficient to obtain cohesion of the particles to a substrate. The deposition efficiency of the particles is significantly determined by their velocity and temperature. Particle velocity correlates with the amount of kinetic energy that is converted to plastic deformation and thermal heating. The initial particle temperature significantly influences the mechanical properties of the particle. Velocity and temperature of the particles have nonlinear dependence on the pressure and temperature of the gas at the nozzle entrance. In this contribution, a simulation model based on the reactingParcelFoam solver of OpenFOAM is presented and applied for an analysis of particle velocity and temperature in the cold spray nozzle. The model combines a compressible description of the gas flow in the nozzle with a Lagrangian particle tracking. The predictions of the simulation model are verified based on an analytical description of the gas flow, the particle acceleration and heating in the nozzle. Based on experimental data, the drag model according to Plessis and Masliyah is identified to be best suited for OpenFOAM modeling particle heating and acceleration in cold spraying.

Acceleration mechanisms for energetic particles in the earth's magnetosphere

International Nuclear Information System (INIS)

Schiferl, S.; Fan, C.Y.; Hsieh, K.C.; Erickson, K.N.; Gloeckler, G.; Hovestadt, D.

1982-01-01

By analyzing data on energetic particle fluxes measured simultaneously with detector systems on several earth satellites, we searched for signatures of different acceleration mechanisms for these particles. One of the samples is an event observed on ATS-6 and IMP-7. IMP-7 was in the dusk quarter at 38 Rsub(E) while ATS-6 was located at local midnight at a distance of 6.6 Rsub(E). Although the flux variations as observed on the two spacecraft both showed 1.5 min. periodicity, there was a 40-second time lag with IMP-7 behind. The results indicate that the particles are accelerated by magnetic field line annihilation, with the ''x-point'' located at approximately 10 Rsub(E)

Particle acceleration in the plasma fields near comet Halley

International Nuclear Information System (INIS)

Somogyi, A.J.; Erdoes, G.; Shapiro, V.D.; Shevchenko, V.I.

1990-01-01

Spacecraft VEGA-1 approached Halley comet to distances less than 10 million km in March 1986. It was equipped with devices capable to detect and measure the energies of charged particles (higher than 50 keV). After a survey of acceleration mechanisms the properties of the 50-800 keV charged particle fluxes observed in various regions around Halley comet are reported. In particular, the regions outside the cometary bow shock, the region between the bow shock and the cometopause, and inside the latter, especially in the magnetic pile-up region are considered. Possible mechanisms responsible for the accelerations of the particle fluxes described are discussed. (author) 73 refs.; 7 figs.; 3 tabs

High rate resistive plate chambers: An inexpensive, fast, large area detector of energetic charged particles for accelerator and non-accelerator applications

International Nuclear Information System (INIS)

Wuest, C.R.; Ables, E.; Bionta, R.M.; Clamp, O.; Haro, M.; Mauger, G.J.; Miller, K.; Olson, H.; Ramsey, P.

1993-05-01

Resistive Plate Chambers, or RPCs, have been used until recently as large detectors of cosmic ray muons. They are now finding use as fast large-area trigger and muon detection systems for different high energy physics detectors such the L3 Detector at LEP and future detectors to be built at the Superconducting Super Collider (SSC) and at the Large Hadron Collider (LHC) at CERN. RPC systems at these accelerators must operate with high efficiency, providing nanosecond timing resolution in particle fluences up to a few tens of kHz/cm 2 -- with thousands of square meters of active area. RPCs are simple and cheap to construct. The authors report here recent work on RPCs using new materials that exhibit a combination of desirable RPC features such as low bulk resistivity, high dielectric strength, low mass, and low cost. These new materials were originally developed for use in electronics assembly areas and other applications, where static electric charge buildup can damage sensitive electrical systems

Solving radiation problems at particle accelerators

Energy Technology Data Exchange (ETDEWEB)

Nikolai V. Mokhov

2001-12-11

At high-intensity high-energy particle accelerators, consequences of a beam-induced radiation impact on machine and detector components, people, environment and complex performance can range from negligible to severe. The specifics, general approach and tools used at such machines for radiation analysis are described. In particular, the world leader Fermilab accelerator complex is considered, with its fixed target and collider experiments, as well as new challenging projects such as LHC, VLHC, muon collider and neutrino factory. The emphasis is on mitigation of deleterious beam-induced radiation effects and on the key role of effective computer simulations.

Solving radiation problems at particle accelerators

International Nuclear Information System (INIS)

Mokhov, N.V.

2001-01-01

At high-intensity high-energy particle accelerators, consequences of a beam-induced radiation impact on machine and detector components, people, environment and complex performance can range from negligible to severe. The specifics, general approach and tools used at such machines for radiation analysis are described. In particular, the world leader Fermilab accelerator complex is considered, with its fixed target and collider experiments, as well as new challenging projects such as LHC, VLHC, muon collider and neutrino factory. The emphasis is on mitigation of deleterious beam-induced radiation effects and on the key role of effective computer simulations

Characteristics of particle beam acceleration on KUMS tandem electrostatic accelerator 5SDH-2

OpenAIRE

谷池, 晃; 古山, 雄一; 北村, 晃

2006-01-01

The KUMS tandem electrostatic accelerator, 5SDH-2, was installed in 1996. Ten years have passed since it installed and we obtain some data for accelerator operations. We report the particle beam characteristics such as relation between beam species and switcher magnet current, and dependence of ion charge fraction on stripper gas thickness. We also try to generate nitrogen ion beams, and low energy ion beams.

Computer-based training for particle accelerator personnel

International Nuclear Information System (INIS)

Silbar, R.R.

1999-01-01

A continuing problem at many laboratories is the training of new operators in the arcane technology of particle accelerators. Presently most of this training occurs on the job, under a mentor. Such training is expensive, and while it provides operational experience, it is frequently lax in providing the physics background needed to truly understand accelerator systems. Using computers in a self-paced, interactive environment can be more effective in meeting this training need. copyright 1999 American Institute of Physics

Recent trends in particle accelerator radiation safety

International Nuclear Information System (INIS)

Ohnesorge, W.F.; Butler, H.M.

1974-01-01

The use of particle accelerators in applied and research activities continues to expand, bringing new machines with higher energy and current capabilities which create radiation safety problems not commonly encountered before. An overview is given of these increased ionizing radiation hazards, along with a discussion of some of the new techniques required in evaluating and controlling them. A computer search of the literature provided a relatively comprehensive list of publications describing accelerator radiation safety problems and related subjects

Stochastic particle acceleration by plasma waves in AGN jets

International Nuclear Information System (INIS)

Li, Hui; Colgate, S.A.; Miller, J.A.

1997-01-01

The free energy stored in the stressed magnetic fields in AGN jets could be dissipated via generating turbulent plasma waves. The authors review several key wave-particle resonant interactions and point out the importance of a broad wave spectrum. Under several idealized assumptions, they show that the transit-time damping process can accelerate electrons to TeV energies in an AGN jet environment, and present a preliminary calculation on the evolution of plasma wave, electron, and photon distributions. The authors especially emphasize several open questions on particle acceleration by waves, and argue that a plausible scenario is to energize electrons out of the thermal background via transit-time damping and further accelerate them by the parallel propagating right-handed waves

Experimental measurement of unsteady drag on shock accelerated micro-particles

Science.gov (United States)

Bordoloi, Ankur; Martinez, Adam; Prestridge, Katherine

2016-11-01

The unsteady drag history of shock accelerated micro-particles in air is investigated in the Horizontal Shock Tube (HST) facility at Los Alamos National laboratory. Drag forces are estimated based on particle size, particle density, and instantaneous velocity and acceleration measured on hundreds of post-shock particle tracks. We use previously implemented 8-frame Particle Tracking Velocimetry/Anemometry (PTVA) diagnostics to analyze particles in high spatiotemporal resolution from individual particle trajectories. We use a simultaneous LED based shadowgraph to register shock location with respect to a moving particle in each frame. To measure particle size accurately, we implement a Phase Doppler Particle Analyzer (PDPA) in synchronization with the PTVA. In this presentation, we will corroborate with more accuracy our earlier observation that post-shock unsteady drag coefficients (CD(t)) are manifold times higher than those predicted by theoretical models. Our results will also show that all CD(t) measurements collapse on a master-curve for a range of particle size, density, Mach number and Reynolds number when time is normalized by a shear velocity based time scale, t* = d/(uf-up) , where d is particle diameter, and uf and up are post-shock fluid and particle velocities.

Particle Acceleration, Magnetic Field Generation, and Emission in Relativistic Pair Jets

Science.gov (United States)

Nishikawa, K.-I.; Ramirez-Ruiz, E.; Hardee, P.; Hededal, C.; Mizuno, Y.

2005-01-01

Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created by relativistic pair jets are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet propagating through an ambient plasma with and without initial magnetic fields. The growth rates of the Weibel instability depends on the distribution of pair jets. Simulations show that the Weibel instability created in the collisionless shock accelerates particles perpendicular and parallel to the jet propagation direction. The simulation results show that this instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields, which contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

Vacuum brazing of OFE Copper-316L stainless steel transition joints without electroplating stainless steel part for application in particle accelerators

International Nuclear Information System (INIS)

Yadav, D.P.; Kumar, Abhay; Ganesh, P.

2015-01-01

Brazed transition Joints between OFE copper and type 316L austenitic stainless steel (SS) find extensive applications in particle accelerators all over the world. In contrast to excellent wettability of OFE copper, austenitic SS is well known for its poor wettability for BVAg-8 ( 72 Ag/ 28 Cu; melting point: 1052 K) braze filler metal (BFM). High surface wettability is believed to be necessary to drag molten BFM into the capillary gap between mating metallic surfaces. Therefore, the widely accepted practice for vacuum brazing of such transition joints involves electroplating of SS parts with nickel or copper to enhance its wettability. A recently concluded in-house study, involving Nb to Ni-plated 316L SS brazing, has demonstrated that satisfactory ingress of BFM into a capillary joint between two dissimilar metals is possible if the poor wettability of one of the mating surfaces is compensated by good wettability of its counterpart. In the light of these observations, the present study was undertaken to explicitly evaluate the requirement of electroplating the SS part for establishment of sound OFE copper-316L SS brazed joints suitable for service in ultra-high vacuum (UHV) of particle accelerators

Development of a Laser-Powered Dielectric Structure-Based Accelerator as a Stand-Alone Particle Source

International Nuclear Information System (INIS)

Yoder, R. B.; Travish, G.; Arab, E. R.; Fong, D.; Hoyer, Z.; Lacroix, U. H.; Vartanian, N.; Rosenzweig, J. B.

2010-01-01

An experimental program to develop and build a dielectric-based slab-symmetric structure (the micro-accelerator platform, or MAP) for generating and accelerating low-energy electrons is underway at UCLA and Manhattanville College. This optical acceleration structure is effectively a resonant cavity powered by a side-coupled laser, and has applications as a radiation source for medicine or industry. We present recent experimental and computational results on the accelerator, and progress toward its incorporation into a self-contained particle source. Such a particle source would incorporate a micron-scale electron emitter and a non-relativistic capture region to enable self-injection into the synchronous field within the accelerator. A prototype of the accelerator itself has been constructed from candidate dielectric materials using micromanufacturing techniques; the current status of the testing program is described. A novel electron emitter incorporating pyroelectric crystals with field-enhancing tips has been demonstrated to produce steady currents; the results are dependent on tip geometry, and appear suitable for injection into a microstructure. Extension of the MAP concept to non-relativistic velocities, as in the stand-alone source, requires a tapered structure that gives rise to numerous complications including beam defocusing and manufacturing challenges; approaches for addressing these complications are mentioned.

Implications of accelerator experiments for models of the Kolar Gold Mine particles

Energy Technology Data Exchange (ETDEWEB)

Sarma, K V.L. [Tata Inst. of Fundamental Research, Bombay (India); Wolfenstein, L [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

1976-03-01

The significance of accelerator searches for the new particles discovered in the Kolar Gold Mine experiments depends on the characteristics of the models of these particles. Models that could give cosmic ray neutrinos a great advantage over accelerator neutrinos are presented. The new particles should be produced in e/sup +/e/sup -/ colliding beams, but the cross-section is model dependent.

CAS CERN Accelerator School: Superconductivity in particle accelerators. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Turner, S [ed.

1996-05-01

These proceedings present the lectures given at the ninth specialized course organized by the CERN Accelerator School (CAS), the topic this time being ``Superconductivity in Particle Accelerators``. This course is basically a repeat of that given at the same location in 1988 whose proceedings were published as CERN 89-04. However, the opportunity was taken to improve the presentation of the various topics and to introduce the latest developments in this rapidly expanding field. First the basic theory of superconductivity is introduced. A review of the materials used for sc magnetics is followed by magnet design requirements, the influence of eddy and persistent currents, and the methods used to provide quench protection. Next follows the basic theory of sc cavities, their materials, high-gradient limitations, the problem of field emission and then their power couplers. After an introduction to cryogenics and cryoplants, the theory of superfluidity is presented followed by a review of the use of superfluid helium. Finally, two seminars detail the impact of superconductors in the design of the LHC and LEP2 accelerators. (orig.).

CAS CERN Accelerator School: Superconductivity in particle accelerators. Proceedings

International Nuclear Information System (INIS)

Turner, S.

1996-05-01

These proceedings present the lectures given at the ninth specialized course organized by the CERN Accelerator School (CAS), the topic this time being ''Superconductivity in Particle Accelerators''. This course is basically a repeat of that given at the same location in 1988 whose proceedings were published as CERN 89-04. However, the opportunity was taken to improve the presentation of the various topics and to introduce the latest developments in this rapidly expanding field. First the basic theory of superconductivity is introduced. A review of the materials used for sc magnetics is followed by magnet design requirements, the influence of eddy and persistent currents, and the methods used to provide quench protection. Next follows the basic theory of sc cavities, their materials, high-gradient limitations, the problem of field emission and then their power couplers. After an introduction to cryogenics and cryoplants, the theory of superfluidity is presented followed by a review of the use of superfluid helium. Finally, two seminars detail the impact of superconductors in the design of the LHC and LEP2 accelerators. (orig.)

Vp x B acceleration

International Nuclear Information System (INIS)

Sugihara, Ryo.

1987-05-01

A unique particle acceleration by an electrostatic (ES) wave, a magnetosonic shock wave as well as an electromagnetic (EM) wave is reviewed. The principle of the acceleration is that when a charged particle is carried across an external magnetic field the charge feels a DC field (the Lorentz force) and is accelerated. The theory for the ES wave acceleration is experimentally verified thought it is semi-quantitative. The shock acceleration is extensively studied theoretically and in a particle simulation method and the application is extended to phenomena in interplanetary space. The EM wave acceleration is based on a trapping in a moving neutral sheet created by the wave magnetic field and the external magnetic field, and the particle can be accelerated indefinitely. A brief sketch on a slow-wave-structure for this acceleration will be given. (author)

Double layer -- a particle accelerator in the magnetosphere

Energy Technology Data Exchange (ETDEWEB)

Fu, Xiangrong [Los Alamos National Laboratory

2015-07-16

Slides present the material under the following topics: Introduction (What is a double layer (DL)? Why is it important? Key unsolved problems); Theory -- time-independent solutions of 1D Vlasov--Poisson system; Particle-in-cell simulations (Current-driven DLs); and Electron acceleration by DL (Betatron acceleration). Key problems include the generation mechanism, stability, and electron acceleration. In summary, recent observations by Van Allen Probes show large number of DLs in the outer radiation belt, associated with enhanced flux of relativistic electrons. Simulations show that ion acoustic double layers can be generated by field-aligned currents. Thermal electrons can gain energy via betatron acceleration in a dipole magnetic field.

Application of Atmospheric Plasma-Sprayed Ferrite Layers for Particle Accelerators

CERN Document Server

Caspers, F; Federmann, S; Taborelli, M; Schulz, C; Bobzin, K; Wu, J

2013-01-01

A common problem in all kinds of cavity-like structures in particle accelerators is the occurrence of RF-resonances. Typically, ferrite plates attached to the walls of such structures as diagnostic devices, kickers or collimators, are used to dampen those undesired modes. However, the heat transfer rate from these plates to the walls is rather limited. Brazing ferrite plates to the walls is not possible in most cases due to the different thermal expansion coefficients. To overcome those limitations, atmospheric plasma spraying techniques have been investigated. Ferrite layers with a thickness from 50 μm to about 300 μm can be deposited on metallic surfaces like stainless steel exhibiting good thermal contact and still reasonable absorption properties. In this paper the technological aspects of plasma deposition are discussed and results of specifically developed RF loss measurement procedures for such thin magnetically lossy layers on metal are presented.

Cryogenic Beam Screens for High-Energy Particle Accelerators

CERN Document Server

Baglin, V; Tavian, L; van Weelderen, R

2013-01-01

Applied superconductivity has become a key enabling technology for high-energy particle accelerators, thus making them large helium cryogenic systems operating at very low temperature. The circulation of high-intensity particle beams in these machines generates energy deposition in the first wall through different processes. For thermodynamic efficiency, it is advisable to intercept these beam-induced heat loads, which may be large in comparison with cryostat heat in-leaks, at higher temperature than that of the superconducting magnets of the accelerator, by means of beam screens located in the magnet apertures. Beam screens may also be used as part of the ultra-high vacuum system of the accelerator, by sheltering the gas molecules cryopumped on the beam pipe from impinging radiation and thus avoiding pressure runaway. Space being extremely tight in the magnet apertures, cooling of the long, slender beam screens also raises substantial problems in cryogenic heat transfer and fluid flow. We present sizing rule...

Acceleration of charged particles by lasers in vacuum

International Nuclear Information System (INIS)

Cicchitelli, L.; Hora, H.; Scheid, W.

1989-01-01

For laser acceleration of electrons (and other charged particles) by lasers to the TeV energy range in vacuum, the scheme of trapping electrons in spatially moving and accelerated intensity gradients or minima of laser fields, the single electron motion in standing wave fields is evaluated in details numerically. Acceleration of the minima results in the acceleration of the electrons as expected from global results of the nonlinear forces. If half-wave length laser pulses propagating in vacuum are used the relativistic exact solutions are derived and evaluated. A disadvantage is the lateral motion requiring a large laser focus. For TeV electron energy, MJ KrF-laser pulses are necessary and the acceleration length is about 10 cm. copyright 1989 American Institute of Physics

Global particle accelerator gets the big chill

CERN Multimedia

Sherriff, Lucy

2004-01-01

Scientists at an international symposium in Beijing have recommended that a new global particle accelerator should be based on "cold" or superconducting technology, bringing the construction of the multi-billion dollar facility one step closer to reality (½ page)

Non-extremal Kerr black holes as particle accelerators

OpenAIRE

Gao, Sijie; Zhong, Changchun

2011-01-01

It has been shown that extremal Kerr black holes can be used as particle accelerators and arbitrarily high energy may be obtained near the event horizon. We study particle collisions near the event horizon (outer horizon) and Cauchy horizon (inner horizon) of a non-extremal Kerr black hole. Firstly, we provide a general proof showing that particles cannot collide with arbitrarily high energies at the outter horizon. Secondly, we show that ultraenergetic collisions can occur near the inner hor...

Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets and Supernova Remnants

Science.gov (United States)

Nishikawa, K.-I.; Hartmann, D. H.; Hardee, P.; Hededal, C.; Mizunno, Y.; Fishman, G. J.

2006-01-01

We performed numerical simulations of particle acceleration, magnetic field generation, and emission from shocks in order to understand the observed emission from relativistic jets and supernova remnants. The investigation involves the study of collisionless shocks, where the Weibel instability is responsible for particle acceleration as well as magnetic field generation. A 3-D relativistic particle-in-cell (RPIC) code has been used to investigate the shock processes in electron-positron plasmas. The evolution of theWeibe1 instability and its associated magnetic field generation and particle acceleration are studied with two different jet velocities (0 = 2,5 - slow, fast) corresponding to either outflows in supernova remnants or relativistic jets, such as those found in AGNs and microquasars. Slow jets have intrinsically different structures in both the generated magnetic fields and the accelerated particle spectrum. In particular, the jet head has a very weak magnetic field and the ambient electrons are strongly accelerated and dragged by the jet particles. The simulation results exhibit jitter radiation from inhomogeneous magnetic fields, generated by the Weibel instability, which has different spectral properties than standard synchrotron emission in a homogeneous magnetic field.

Charged particle acceleration with plasmas

International Nuclear Information System (INIS)

Bravo O, A.

1989-01-01

Under certain conditions it is possible to create spatial charge waves (OCE) in a plasma (ionized gas) through some disturbance mechanism, the phenomenon produces electric fields of high intensity that are propagated at velocities near to a c. When charged particles are connected to such OCE they may be accelerated to very high energies in short distances. At present electric fields of approximately 10 7 V/cm have been observed. (Author). 4 refs

JMS-based SOA monitors CERN particle accelerators

CERN Multimedia

Seeley, Rich

2007-01-01

"Service-oriented architecture (SOA) may not exactly be nuclear physics, but at the CERN (European Organization for Nuclear Research) physics laboratory on the border of France and Switzerland, an SOA system is watching over giant particle accelerators." (1,5 page)

Cavitation Inception on Microparticles: A Self-Propelled Particle Accelerator

DEFF Research Database (Denmark)

Arora, M.; Ohl, C.-D.; Mørch, Knud Aage

2004-01-01

Corrugated, hydrophilic particles with diameters between 30 and 150 mum are found to cause cavitation inception at their surfaces when they are exposed to a short, intensive tensile stress wave. The growing cavity accelerates the particle into translatory motion until the tensile stress decreases...

14. conference on accelerators of charged particles. Annotations of reports

International Nuclear Information System (INIS)

1994-01-01

Annotations of reports made at the 14 Conference on accelerators of charged particles are presented. The Conference took place 25 - 27 October, 1994 in IHEP, Protvino. Modern trends of development of cyclic and linear accelerators, as well as heavy ion accelerators and colliders have been discussed. Problems of developing accelerators on superhigh energy have been considered. Considerable attention has been paid to accelerating structures, power SHF equipment, beam monitoring systems as well as magnetic and vacuum systems of accelerators. Beam dynamics in accelerators and storage has been considered and new acceleration technique have been proposed. Utilization of accelerators for medicine and other applied purposes has been discussed

GALACTIC AND EXTRAGALACTIC SUPERNOVA REMNANTS AS SITES OF PARTICLE ACCELERATION

Directory of Open Access Journals (Sweden)

Manami Sasaki

2013-12-01

Full Text Available Supernova remnants, owing to their strong shock waves, are likely sources of Galactic cosmic rays. Studies of supernova remnants in X-rays and gamma rays provide us with new insights into the acceleration of particles to high energies. This paper reviews the basic physics of supernova remnant shocks and associated particle acceleration and radiation processes. In addition, the study of supernova remnant populations in nearby galaxies and the implications for Galactic cosmic ray distribution are discussed.

Particle accelerators: the next big step

International Nuclear Information System (INIS)

Lawson, J.

1982-01-01

Ideas which are currently under discussion for increasing the present energy range of particle accelerators but which are also economical in resources and do not demand elaborate techniques, are examined. Among the possible methods reviewed are the use of laser beams, the electron ring concept, and the use of wake fields left by electrons in storage rings. (U.K.)

Physics of compact radio sources. I. Particle acceleration and flux variations

International Nuclear Information System (INIS)

Pacholczyk, A.G.; Scott, J.S.

1976-01-01

The observed patterns of variability of compact radio sources may be explained by assuming that the radio components are plasmons containing relativistic particles, and by applying a model with the following features: (1) the plasmons are ejected at high speed into the interstellar medium in the nuclei of active galaxies: (2) ram pressure confinement of the plasmons leads to Rayleigh-Taylor and Kelvin-Helmholtz instabilities therein; (3) turbulence is thereby introduced into the plasmons; (4) the turbulence amplifies the plasmon magnetic field (for a short period) and this leads to betatron aceleration of the relativistic particles; (5) the turbulence vortices continue to accelerate the particles by the second-order Fermi acceleration mechanism. The emission patterns are the result of the combination of these accelerations and adiabatic losses

Reducing field emission in the superconducting rf cavities for the next generation of particle accelerators

International Nuclear Information System (INIS)

Shu, Q.S.; Hartung, W.; Leibovich, A.; Kirchgessner, J.; Moffat, D.; Padamsee, H.; Rubin, D.; Sears, J.

1991-01-01

This paper reports on field emission, which is an obstacle to reaching the higher fields called for in future applications of superconducting radio frequency cavities to particle accelerators. The authors used heat treatment up to 1500 degrees C in an ultra-high vacuum furnace, along with processing of cavities and temperature mapping, to suppress field emission and analyze emitter properties. In 27 tests of 1-cell 1500 MHz fired accelerating cavities, on the average the accelerating field E acc increased to 24 MV/m (H pk = 1250 Oe) from 13 MV/m with chemical treatment alone; the highest E acc reached was 30.5 MV/m

Particle Acceleration in Mildly Relativistic Shearing Flows: The Interplay of Systematic and Stochastic Effects, and the Origin of the Extended High-energy Emission in AGN Jets

Energy Technology Data Exchange (ETDEWEB)

Liu, Ruo-Yu; Rieger, F. M.; Aharonian, F. A., E-mail: ruoyu@mpi-hd.mpg.de, E-mail: frank.rieger@mpi-hd.mpg.de, E-mail: aharon@mpi-hd.mpg.de [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2017-06-10

The origin of the extended X-ray emission in the large-scale jets of active galactic nuclei (AGNs) poses challenges to conventional models of acceleration and emission. Although electron synchrotron radiation is considered the most feasible radiation mechanism, the formation of the continuous large-scale X-ray structure remains an open issue. As astrophysical jets are expected to exhibit some turbulence and shearing motion, we here investigate the potential of shearing flows to facilitate an extended acceleration of particles and evaluate its impact on the resultant particle distribution. Our treatment incorporates systematic shear and stochastic second-order Fermi effects. We show that for typical parameters applicable to large-scale AGN jets, stochastic second-order Fermi acceleration, which always accompanies shear particle acceleration, can play an important role in facilitating the whole process of particle energization. We study the time-dependent evolution of the resultant particle distribution in the presence of second-order Fermi acceleration, shear acceleration, and synchrotron losses using a simple Fokker–Planck approach and provide illustrations for the possible emergence of a complex (multicomponent) particle energy distribution with different spectral branches. We present examples for typical parameters applicable to large-scale AGN jets, indicating the relevance of the underlying processes for understanding the extended X-ray emission and the origin of ultrahigh-energy cosmic rays.

Applications of FLUKA Monte Carlo code for nuclear and accelerator physics

CERN Document Server

Battistoni, Giuseppe; Brugger, Markus; Campanella, Mauro; Carboni, Massimo; Empl, Anton; Fasso, Alberto; Gadioli, Ettore; Cerutti, Francesco; Ferrari, Alfredo; Ferrari, Anna; Lantz, Matthias; Mairani, Andrea; Margiotta, M; Morone, Christina; Muraro, Silvia; Parodi, Katerina; Patera, Vincenzo; Pelliccioni, Maurizio; Pinsky, Lawrence; Ranft, Johannes; Roesler, Stefan; Rollet, Sofia; Sala, Paola R; Santana, Mario; Sarchiapone, Lucia; Sioli, Maximiliano; Smirnov, George; Sommerer, Florian; Theis, Christian; Trovati, Stefania; Villari, R; Vincke, Heinz; Vincke, Helmut; Vlachoudis, Vasilis; Vollaire, Joachim; Zapp, Neil

2011-01-01

FLUKA is a general purpose Monte Carlo code capable of handling all radiation components from thermal energies (for neutrons) or 1keV (for all other particles) to cosmic ray energies and can be applied in many different fields. Presently the code is maintained on Linux. The validity of the physical models implemented in FLUKA has been benchmarked against a variety of experimental data over a wide energy range, from accelerator data to cosmic ray showers in the Earth atmosphere. FLUKA is widely used for studies related both to basic research and to applications in particle accelerators, radiation protection and dosimetry, including the specific issue of radiation damage in space missions, radiobiology (including radiotherapy) and cosmic ray calculations. After a short description of the main features that make FLUKA valuable for these topics, the present paper summarizes some of the recent applications of the FLUKA Monte Carlo code in the nuclear as well high energy physics. In particular it addresses such top...

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

Energy Technology Data Exchange (ETDEWEB)

Spentzouris, P.; /Fermilab; Cary, J.; /Tech-X, Boulder; McInnes, L.C.; /Argonne; Mori, W.; /UCLA; Ng, C.; /SLAC; Ng, E.; Ryne, R.; /LBL, Berkeley

2011-11-14

The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization

Particle acceleration at quasi-perpendicular shock waves: Theory and observations at 1 AU

International Nuclear Information System (INIS)

Parker, L. Neergaard; Zank, G. P.; Hu, Q.

2014-01-01

The injection of particles into the diffusive shock acceleration mechanism at highly perpendicular (where θ Bn > 70°) interplanetary shocks is investigated. This extends the previous study of Neergaard Parker and Zank which focused on the injection problem at quasi-parallel interplanetary shocks. We use observations at 1 AU to construct upstream Maxwellian and κ-distributions that are then diffusively accelerated by the shock, thus yielding the downstream accelerated particle distribution. We compare the theoretical accelerated particle distribution to observations at 1 AU using Advanced Composition Explorer data. We classify our results for quasi-perpendicular shocks into three subcategories: those with ratios of the theoretical spectral index to observed power law of >1, ∼ 1, and <1, and compare the magnetic power spectral density plots of these categories. We find that in general the assumed upstream particle distribution that best fits the energetic particle observations is best represented by a κ-distribution, with κ = 4. The magnetic field fluctuations were representative of quasi-perpendicular shocks and showed no particular bias toward our spectral ratio subcategories. The subcategory with spectral ratio <0.9 yielded the largest injection energies for all groups. In all but two of the cases in this study, there were enough particles in the solar wind thermal core to account for the accelerated distribution, thereby giving a lower limit to the required injection energy needed to diffusively accelerate particles at a quasi-perpendicular interplanetary shock. In the remaining two cases, an additional population of particles was required to match the appropriate amplitude of the spectral index. For these cases, we used a low energy (1-50 keV) v –5 spectrum advocated by Fisk and Gloeckler.

Physics of high energy particle accelerators. AIP conference proceedings No. 127

International Nuclear Information System (INIS)

Month, M.; Dahl, P.F.; Dienes, M.

1985-01-01

Topics covered in this workshop include accelerator physics, particle physics, and new acceleration methods. Eighteen lectures were presented. Individual abstracts were prepared separately for the data base

Cavitation inception on microparticles: a self-propelled particle accelerator

NARCIS (Netherlands)

Arora, M.; Ohl, C.D.; Morch, Knud Aage

2004-01-01

Corrugated, hydrophilic particles with diameters between 30 and 150   μm are found to cause cavitation inception at their surfaces when they are exposed to a short, intensive tensile stress wave. The growing cavity accelerates the particle into translatory motion until the tensile stress decreases,

History and Technology Developments of Radio Frequency (RF) Systems for Particle Accelerators

Science.gov (United States)

Nassiri, A.; Chase, B.; Craievich, P.; Fabris, A.; Frischholz, H.; Jacob, J.; Jensen, E.; Jensen, M.; Kustom, R.; Pasquinelli, R.

2016-04-01

This article attempts to give a historical account and review of technological developments and innovations in radio frequency (RF) systems for particle accelerators. The evolution from electrostatic field to the use of RF voltage suggested by R. Wideröe made it possible to overcome the shortcomings of electrostatic accelerators, which limited the maximum achievable electric field due to voltage breakdown. After an introduction, we will provide reviews of technological developments of RF systems for particle accelerators.

The charged particle accelerators subsystems modeling

International Nuclear Information System (INIS)

Averyanov, G P; Kobylyatskiy, A V

2017-01-01

Presented web-based resource for information support the engineering, science and education in Electrophysics, containing web-based tools for simulation subsystems charged particle accelerators. Formulated the development motivation of Web-Environment for Virtual Electrophysical Laboratories. Analyzes the trends of designs the dynamic web-environments for supporting of scientific research and E-learning, within the framework of Open Education concept. (paper)

Advanced Accelerators for Medical Applications

Science.gov (United States)

Uesaka, Mitsuru; Koyama, Kazuyoshi

We review advanced accelerators for medical applications with respect to the following key technologies: (i) higher RF electron linear accelerator (hereafter “linac”); (ii) optimization of alignment for the proton linac, cyclotron and synchrotron; (iii) superconducting magnet; (iv) laser technology. Advanced accelerators for medical applications are categorized into two groups. The first group consists of compact medical linacs with high RF, cyclotrons and synchrotrons downsized by optimization of alignment and superconducting magnets. The second group comprises laser-based acceleration systems aimed of medical applications in the future. Laser plasma electron/ion accelerating systems for cancer therapy and laser dielectric accelerating systems for radiation biology are mentioned. Since the second group has important potential for a compact system, the current status of the established energy and intensity and of the required stability are given.

Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

Energy Technology Data Exchange (ETDEWEB)

Rubel, Oliver; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Wu, Kesheng; Prabhat,; Weber, Gunther H.; Ushizima, Daniela M.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

2009-10-19

Numerical simulations of laser wakefield particle accelerators play a key role in the understanding of the complex acceleration process and in the design of expensive experimental facilities. As the size and complexity of simulation output grows, an increasingly acute challenge is the practical need for computational techniques that aid in scientific knowledge discovery. To that end, we present a set of data-understanding algorithms that work in concert in a pipeline fashion to automatically locate and analyze high energy particle bunches undergoing acceleration in very large simulation datasets. These techniques work cooperatively by first identifying features of interest in individual timesteps, then integrating features across timesteps, and based on the information derived perform analysis of temporally dynamic features. This combination of techniques supports accurate detection of particle beams enabling a deeper level of scientific understanding of physical phenomena than hasbeen possible before. By combining efficient data analysis algorithms and state-of-the-art data management we enable high-performance analysis of extremely large particle datasets in 3D. We demonstrate the usefulness of our methods for a variety of 2D and 3D datasets and discuss the performance of our analysis pipeline.

High and ultra-high vacuum pumping techniques: applications in accelerators and storage rings

International Nuclear Information System (INIS)

Schaefer, G.

1988-01-01

A survey is given on gas transfer pumps, especially Turbomolecular pumps, and entrapment pumps (cryopumps and getter pumps) mainly with regard to their application in evacuating particle accelerators and storage rings. (A.C.A.S.) [pt

Applications of the ARGUS code in accelerator physics

International Nuclear Information System (INIS)

Petillo, J.J.; Mankofsky, A.; Krueger, W.A.; Kostas, C.; Mondelli, A.A.; Drobot, A.T.

1993-01-01

ARGUS is a three-dimensional, electromagnetic, particle-in-cell (PIC) simulation code that is being distributed to U.S. accelerator laboratories in collaboration between SAIC and the Los Alamos Accelerator Code Group. It uses a modular architecture that allows multiple physics modules to share common utilities for grid and structure input., memory management, disk I/O, and diagnostics, Physics modules are in place for electrostatic and electromagnetic field solutions., frequency-domain (eigenvalue) solutions, time- dependent PIC, and steady-state PIC simulations. All of the modules are implemented with a domain-decomposition architecture that allows large problems to be broken up into pieces that fit in core and that facilitates the adaptation of ARGUS for parallel processing ARGUS operates on either Cray or workstation platforms, and MOTIF-based user interface is available for X-windows terminals. Applications of ARGUS in accelerator physics and design are described in this paper

Accurate and efficient spin integration for particle accelerators

International Nuclear Information System (INIS)

Abell, Dan T.; Meiser, Dominic; Ranjbar, Vahid H.; Barber, Desmond P.

2015-01-01

Accurate spin tracking is a valuable tool for understanding spin dynamics in particle accelerators and can help improve the performance of an accelerator. In this paper, we present a detailed discussion of the integrators in the spin tracking code GPUSPINTRACK. We have implemented orbital integrators based on drift-kick, bend-kick, and matrix-kick splits. On top of the orbital integrators, we have implemented various integrators for the spin motion. These integrators use quaternions and Romberg quadratures to accelerate both the computation and the convergence of spin rotations. We evaluate their performance and accuracy in quantitative detail for individual elements as well as for the entire RHIC lattice. We exploit the inherently data-parallel nature of spin tracking to accelerate our algorithms on graphics processing units.

Accurate and efficient spin integration for particle accelerators

Energy Technology Data Exchange (ETDEWEB)

Abell, Dan T.; Meiser, Dominic [Tech-X Corporation, Boulder, CO (United States); Ranjbar, Vahid H. [Brookhaven National Laboratory, Upton, NY (United States); Barber, Desmond P. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2015-01-15

Accurate spin tracking is a valuable tool for understanding spin dynamics in particle accelerators and can help improve the performance of an accelerator. In this paper, we present a detailed discussion of the integrators in the spin tracking code GPUSPINTRACK. We have implemented orbital integrators based on drift-kick, bend-kick, and matrix-kick splits. On top of the orbital integrators, we have implemented various integrators for the spin motion. These integrators use quaternions and Romberg quadratures to accelerate both the computation and the convergence of spin rotations. We evaluate their performance and accuracy in quantitative detail for individual elements as well as for the entire RHIC lattice. We exploit the inherently data-parallel nature of spin tracking to accelerate our algorithms on graphics processing units.

Advanced Accelerators: Particle, Photon and Plasma Wave Interactions

Energy Technology Data Exchange (ETDEWEB)

Williams, Ronald L. [Florida A & M University, Tallahassee, FL (United States)

2017-06-29

The overall objective of this project was to study the acceleration of electrons to very high energies over very short distances based on trapping slowly moving electrons in the fast moving potential wells of large amplitude plasma waves, which have relativistic phase velocities. These relativistic plasma waves, or wakefields, are the basis of table-top accelerators that have been shown to accelerate electrons to the same high energies as kilometer-length linear particle colliders operating using traditional decades-old acceleration techniques. The accelerating electrostatic fields of the relativistic plasma wave accelerators can be as large as GigaVolts/meter, and our goal was to study techniques for remotely measuring these large fields by injecting low energy probe electron beams across the plasma wave and measuring the beam’s deflection. Our method of study was via computer simulations, and these results suggested that the deflection of the probe electron beam was directly proportional to the amplitude of the plasma wave. This is the basis of a proposed diagnostic technique, and numerous studies were performed to determine the effects of changing the electron beam, plasma wave and laser beam parameters. Further simulation studies included copropagating laser beams with the relativistic plasma waves. New interesting results came out of these studies including the prediction that very small scale electron beam bunching occurs, and an anomalous line focusing of the electron beam occurs under certain conditions. These studies were summarized in the dissertation of a graduate student who obtained the Ph.D. in physics. This past research program has motivated ideas for further research to corroborate these results using particle-in-cell simulation tools which will help design a test-of-concept experiment in our laboratory and a scaled up version for testing at a major wakefield accelerator facility.

Relativistic acceleration of captured particles by a longitudinal wave in a slightly inhomogeneous plasma

International Nuclear Information System (INIS)

Erokhin, N.S.; Zol'nikova, N.N.; Mikhajlovskaya, L.A.

1991-01-01

Relativistic acceleration of charged particles, captured by a longitudinal wave in a slightly inhomogeneous plasma without an external magnetic field is considered numerically and analytically. It is shown that with the growth of the plasma inhomogeneity parameter the maximum energy of accelerated captured particles exponentially increases. Attention is paid to the possibility of 'eternal' confinement and, respectively, unlimited acceleration of captured particles by an undamped longitudinal wave in a plasma without a magnetic field

CAS CERN Accelerator School: Power converters for particle accelerators

International Nuclear Information System (INIS)

Turner, S.

1990-01-01

This volume presents the proceedings of the fifth specialized course organized by the CERN Accelerator School, the subject on this occasion being power converters for particle accelerators. The course started with lectures on the classification and topologies of converters and on the guidelines for achieving high performance. It then went on to cover the more detailed aspects of feedback theory, simulation, measurements, components, remote control, fault diagnosis and equipment protection as well as systems and grid-related problems. The important topics of converter specification, procurement contract management and the likely future developments in semiconductor components were also covered. Although the course was principally directed towards DC and slow-pulsed supplies, lectures were added on fast converters and resonant excitation. Finally the programme was rounded off with three seminars on the related fields of Tokamak converters, battery energy storage for electric vehicles, and the control of shaft generators in ships. (orig.)

Accelerator cavities as a probe of millicharged particles

Energy Technology Data Exchange (ETDEWEB)

Gies, H. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Jaeckel, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2006-08-15

We investigate Schwinger pair production of millicharged fermions in the strong electric field of cavities used for particle accelerators. Even without a direct detection mechanism at hand, millicharged particles, if they exist, contribute to the energy loss of the cavity and thus leave an imprint on the cavity's quality factor. Already conservative estimates substantially constrain the electric charge of these hypothetical particles; the resulting bounds are competitive with the currently best laboratory bounds which arise from experiments based on polarized laser light propagating in a magnetic field. We propose an experimental setup for measuring the electric current comprised of the millicharged particles produced in the cavity. (orig.)

Safety training and safe operating procedures written for PBFA (Particle Beam Fusion Accelerator) II and applicable to other pulsed power facilities

Energy Technology Data Exchange (ETDEWEB)

Donovan, G.L.; Goldstein, S.A.

1986-12-01

To ensure that work in advancing pulsed power technology is performed with an acceptably low risk, pulsed power research facilities at Sandia National Laboratories must satisfy general safety guidelines established by the Department of Energy, policies and formats of the Environment, Safety, and Health (ES and H) Department, and detailed procedures formulated by the Pulsed Power Sciences Directorate. The approach to safety training and to writing safe operating procedures, and the procedures presented here are specific to the Particle Beam Fusion Accelerator II (PBFA II) Facility but are applicable as guidelines to other research and development facilities which have similar hazards.

Safety training and safe operating procedures written for PBFA [Particle Beam Fusion Accelerator] II and applicable to other pulsed power facilities

International Nuclear Information System (INIS)

Donovan, G.L.; Goldstein, S.A.

1986-12-01

To ensure that work in advancing pulsed power technology is performed with an acceptably low risk, pulsed power research facilities at Sandia National Laboratories must satisfy general safety guidelines established by the Department of Energy, policies and formats of the Environment, Safety, and Health (ES and H) Department, and detailed procedures formulated by the Pulsed Power Sciences Directorate. The approach to safety training and to writing safe operating procedures, and the procedures presented here are specific to the Particle Beam Fusion Accelerator II (PBFA II) Facility but are applicable as guidelines to other research and development facilities which have similar hazards

Radiation reaction effect on laser driven auto-resonant particle acceleration

International Nuclear Information System (INIS)

Sagar, Vikram; Sengupta, Sudip; Kaw, P. K.

2015-01-01

The effects of radiation reaction force on laser driven auto-resonant particle acceleration scheme are studied using Landau-Lifshitz equation of motion. These studies are carried out for both linear and circularly polarized laser fields in the presence of static axial magnetic field. From the parametric study, a radiation reaction dominated region has been identified in which the particle dynamics is greatly effected by this force. In the radiation reaction dominated region, the two significant effects on particle dynamics are seen, viz., (1) saturation in energy gain by the initially resonant particle and (2) net energy gain by an initially non-resonant particle which is caused due to resonance broadening. It has been further shown that with the relaxation of resonance condition and with optimum choice of parameters, this scheme may become competitive with the other present-day laser driven particle acceleration schemes. The quantum corrections to the Landau-Lifshitz equation of motion have also been taken into account. The difference in the energy gain estimates of the particle by the quantum corrected and classical Landau-Lifshitz equation is found to be insignificant for the present day as well as upcoming laser facilities

State registration and inspection programs for particle accelerators

International Nuclear Information System (INIS)

Bailey, E.D.

1976-01-01

The Suggested State Regulations for Control of Radiation(SSRCR) are recommended by the Council of State Governments and the National Conference of Radiation Control Program Directors as the model regulations which states should adopt in order to have adequate regulation and uniformity from state to state. These regulations are used as a basis for reviewing the current status of accelerator regulation in each state. The SSRCR does contain a separate part for registration (Part B--Registration of Radiation Machine Facilities and Services) and a separate part (Part I--Radiation Safety Requirements for Particle Accelerators) with specific requirements for the possession and use of accelerators. In addition, medical accelerators have additional requirements in Part F--X-Rays in The Heating Acts. These regulations specify requirements related to limitations of use, shielding and safety design requirements, control and interlock systems, warning devices, operating procedures, radiation monitoring, and calibration of medical accelerators

SMALL-SCALE MAGNETIC ISLANDS IN THE SOLAR WIND AND THEIR ROLE IN PARTICLE ACCELERATION. II. PARTICLE ENERGIZATION INSIDE MAGNETICALLY CONFINED CAVITIES

International Nuclear Information System (INIS)

Khabarova, Olga V.; Zank, Gary P.; Li, Gang; Le Roux, Jakobus A.; Webb, Gary M.; Malandraki, Olga E.

2016-01-01

We explore the role of heliospheric magnetic field configurations and conditions that favor the generation and confinement of small-scale magnetic islands associated with atypical energetic particle events (AEPEs) in the solar wind. Some AEPEs do not align with standard particle acceleration mechanisms, such as flare-related or simple diffusive shock acceleration processes related to interplanetary coronal mass ejections (ICMEs) and corotating interaction regions (CIRs). As we have shown recently, energetic particle flux enhancements may well originate locally and can be explained by particle acceleration in regions filled with small-scale magnetic islands with a typical width of ∼0.01 au or less, which is often observed near the heliospheric current sheet (HCS). The particle energization is a consequence of magnetic reconnection-related processes in islands experiencing either merging or contraction, observed, for example, in HCS ripples. Here we provide more observations that support the idea and the theory of particle energization produced by small-scale-flux-rope dynamics (Zank et al. and Le Roux et al.). If the particles are pre-accelerated to keV energies via classical mechanisms, they may be additionally accelerated up to 1–1.5 MeV inside magnetically confined cavities of various origins. The magnetic cavities, formed by current sheets, may occur at the interface of different streams such as CIRs and ICMEs or ICMEs and coronal hole flows. They may also form during the HCS interaction with interplanetary shocks (ISs) or CIRs/ICMEs. Particle acceleration inside magnetic cavities may explain puzzling AEPEs occurring far beyond ISs, within ICMEs, before approaching CIRs as well as between CIRs.

Accelerator mass spectrometry-current status in techniques and applications

International Nuclear Information System (INIS)

Imamura, Mineo; Nagai, Hisao; Kobayashi, Koichi.

1991-01-01

Accelerator mass spectrometry (AMS) is the mass spectrometry by incorporating an accelerator. After samples are ionized, they are accelerated to a certain energy, and mass, energy, nuclear charge (atomic number) are distinguished, and ion counting is made one by one with a heavy ion detector. For the measurement of long half-life radioisotopes, mass spectrometry has been used because of the high sensitivity, but in low energy mass spectrometry, there are the difficulties due to the mixing of the molecular ions having nearly same mass and the existence of isobars. One of the methods solving these difficulties is an accelerator which enables background-free measurement. The progress of AMS is briefly described, and at present, it is carried out in about 30 facilities in the world. In AMS, the analysis is carried out in the order of the ionization of samples, the acceleration of beam, the electron stripping with a thin film, the sorting of the momentum and energy of beam and the identification of particles. The efficiency, sensitivity and accuracy of detection and the application are reported. (K.I.)

Particle acceleration in the interplanetary medium

International Nuclear Information System (INIS)

Engelmann, J.J.

1987-07-01

Variations in solar wind properties are dominated by a number of high speed streams. By interacting with the quiet wind, the fast streams give rise in the first case to a travelling shock wave, in the second case to a pair of forward and backward shock waves, by which the interaction region, corotating with the sun, is bounded. Two acceleration mechanisms are invoked to account for the energetic ion flux increases: 1) The first order Fermi process, whereby particles increase their energy by compression between converging magnetic scattering centers, located upstream and downstream of the shock. 2) The shock drift mechanism. The composition and the spectrum of the accelerated ions suggest that they probably originate from the suprathermal tail of the solar wind distribution [fr

Accelerator microanalysis

International Nuclear Information System (INIS)

Tuniz, C.

1997-01-01

Particle accelerators have been developed more than sixty years ago to investigate nuclear and atomic phenomena. A major shift toward applications of accelerators in the study of materials structure and composition in inter-disciplinary projects has been witnessed in the last two decades. The Australian Nuclear Science and Technology Organisation (ANSTO) has developed advanced research programs based on the use of particle and photon beams. Atmospheric pollution problems are investigated at the 3 MV Van de Graff accelerator using ion beam analysis techniques to detect toxic elements in aerosol particles. High temperature superconductor and semiconductor materials are characterised using the recoil of iodine and other heavy ions produced at ANTARES, the 10-MV Tandem accelerator. A heavy-ion microprobe is presently being developed at ANTARES to map elemental concentrations of specific elements with micro-size resolution. An Accelerator mass Spectrometry (AMS) system has been developed at ANSTO for the ultra-sensitive detection of Carbon-14, Iodine-129 and other long-lived radioisotopes. This AMS spectrometer is a key instrument for climate change studies and international safeguards. ANSTO is also managing the Australian Synchrotron Research program based on facilities developed at the Photon Factory (Japan) and at the Advanced Photon Source (USA). Advanced projects in biology, materials chemistry, structural condensed matter and other disciplines are being promoted by a consortium involving Australian universities and research institutions. This paper will review recent advances in the use of particle accelerators, with a particular emphasis on applications developed at ANSTO and related to problems of international concern, such as global environmental change, public health and nuclear proliferation

ELECTROMAGNETIC SIMULATIONS OF LINEAR PROTON ACCELERATOR STRUCTURES USING DIELECTRIC WALL ACCELERATORS

International Nuclear Information System (INIS)

Nelson, S; Poole, B; Caporaso, G

2007-01-01

Proton accelerator structures for medical applications using Dielectric Wall Accelerator (DWA) technology allow for the utilization of high electric field gradients on the order of 100 MV/m to accelerate the proton bunch. Medical applications involving cancer therapy treatment usually desire short bunch lengths on the order of hundreds of picoseconds in order to limit the extent of the energy deposited in the tumor site (in 3D space, time, and deposited proton charge). Electromagnetic simulations of the DWA structure, in combination with injections of proton bunches have been performed using 3D finite difference codes in combination with particle pushing codes. Electromagnetic simulations of DWA structures includes these effects and also include the details of the switch configuration and how that switch time affects the electric field pulse which accelerates the particle beam

Cryogenic systems for detectors and particle accelerators

International Nuclear Information System (INIS)

Sondericker, J.H.

1988-01-01

It's been one hundred years since the first successful experiments were carried out leading to the liquefaction of oxygen which birthed the field of cryogenics and about sixty years since cryogenics went commercial. Originally, cryogenics referred to the technology and art of producing low temperatures but today the definition adopted by the XII Congress of the International Institute of Refrigeration describes cryogenics as the study of phenomena, techniques, and concepts occurring at our pertaining to temperatures below 120 K. Modern acceptance of the importance and use of cryogenic fluids continues to grow. By far, the bulk of cryogenic products are utilized by industry for metal making, agriculture, medicine, food processing and as efficient storage of fuels. Cryogenics has found many uses in the scientific community as well, enabling the development of ultra low noise amplifiers, fast cold electronics, cryopumped ultra high vacuums, the production of intense magnetic fields and low loss power transmission through the sue of cryogenically cooled superconductors. High energy physic research has been and continues to use cryogenic hardware to produce liquids used as detector targets and to produce refrigeration necessary to cool superconducting magnets to design temperature for particle accelerator applications. In fact, today's super accelerators achieve energies that would be impossible to reach with conventional copper magnets, demonstrating that cryogenics has become an indispensable ingredient in today's scientific endeavors

Accurate and efficient spin integration for particle accelerators

Directory of Open Access Journals (Sweden)

Dan T. Abell

2015-02-01

Full Text Available Accurate spin tracking is a valuable tool for understanding spin dynamics in particle accelerators and can help improve the performance of an accelerator. In this paper, we present a detailed discussion of the integrators in the spin tracking code gpuSpinTrack. We have implemented orbital integrators based on drift-kick, bend-kick, and matrix-kick splits. On top of the orbital integrators, we have implemented various integrators for the spin motion. These integrators use quaternions and Romberg quadratures to accelerate both the computation and the convergence of spin rotations. We evaluate their performance and accuracy in quantitative detail for individual elements as well as for the entire RHIC lattice. We exploit the inherently data-parallel nature of spin tracking to accelerate our algorithms on graphics processing units.

The theory of accelerated particles in AVF cyclotrons

International Nuclear Information System (INIS)

Schulte, W.M.

1978-01-01

This thesis deals with the study of the motion of accelerated charged particles in an AVF cyclotron. This study has been done on behalf of the VICKSI- project of the Hahn-Meitner-Institut in West Berlin. A new theory is developed which facilitates an accurate description of the influence of the acceleration on the motion in the median plane of a cyclotron. The theory is applied to systems with 1 or 2 Dee electrodes, the frequency of the accelerating voltage being equal to the revolution frequency of the particles or a higher harmonic of this frequency. It turned out that the betatron oscillations in the radial phase space may be disturbed considerably as a result of the acceleration. In the theory the author makes use of the Hamilton formalism. After a number of canonical transformations a Hamilton function was found, in which the most important effects show themselves clearly. The corresponding equations of motion can be solved very quickly with the help of a simple computer program. The results of this theory are in agreement with those of extensive numerical orbit integration programmes. In this thesis attention is also devoted to the centering of the beam in the VICKSI cyclotron just after injection, the possibility to obtain single-turn extraction and the interpretation of the high frequency phase measurements. (Auth.)

Applying the accelerator

Energy Technology Data Exchange (ETDEWEB)

Barbalat, Oscar

1989-12-15

Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology.

Applying the accelerator

International Nuclear Information System (INIS)

Barbalat, Oscar

1989-01-01

Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology

When is quasi-linear theory exact. [particle acceleration

Science.gov (United States)

Jones, F. C.; Birmingham, T. J.

1975-01-01

We use the cumulant expansion technique of Kubo (1962, 1963) to derive an integrodifferential equation for the average one-particle distribution function for particles being accelerated by electric and magnetic fluctuations of a general nature. For a very restricted class of fluctuations, the equation for this function degenerates exactly to a differential equation of Fokker-Planck type. Quasi-linear theory, including the adiabatic assumption, is an exact theory only for this limited class of fluctuations.

Support Vector Machine Based on Adaptive Acceleration Particle Swarm Optimization

Science.gov (United States)

Abdulameer, Mohammed Hasan; Othman, Zulaiha Ali

2014-01-01

Existing face recognition methods utilize particle swarm optimizer (PSO) and opposition based particle swarm optimizer (OPSO) to optimize the parameters of SVM. However, the utilization of random values in the velocity calculation decreases the performance of these techniques; that is, during the velocity computation, we normally use random values for the acceleration coefficients and this creates randomness in the solution. To address this problem, an adaptive acceleration particle swarm optimization (AAPSO) technique is proposed. To evaluate our proposed method, we employ both face and iris recognition based on AAPSO with SVM (AAPSO-SVM). In the face and iris recognition systems, performance is evaluated using two human face databases, YALE and CASIA, and the UBiris dataset. In this method, we initially perform feature extraction and then recognition on the extracted features. In the recognition process, the extracted features are used for SVM training and testing. During the training and testing, the SVM parameters are optimized with the AAPSO technique, and in AAPSO, the acceleration coefficients are computed using the particle fitness values. The parameters in SVM, which are optimized by AAPSO, perform efficiently for both face and iris recognition. A comparative analysis between our proposed AAPSO-SVM and the PSO-SVM technique is presented. PMID:24790584

Support Vector Machine Based on Adaptive Acceleration Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Mohammed Hasan Abdulameer

2014-01-01

Full Text Available Existing face recognition methods utilize particle swarm optimizer (PSO and opposition based particle swarm optimizer (OPSO to optimize the parameters of SVM. However, the utilization of random values in the velocity calculation decreases the performance of these techniques; that is, during the velocity computation, we normally use random values for the acceleration coefficients and this creates randomness in the solution. To address this problem, an adaptive acceleration particle swarm optimization (AAPSO technique is proposed. To evaluate our proposed method, we employ both face and iris recognition based on AAPSO with SVM (AAPSO-SVM. In the face and iris recognition systems, performance is evaluated using two human face databases, YALE and CASIA, and the UBiris dataset. In this method, we initially perform feature extraction and then recognition on the extracted features. In the recognition process, the extracted features are used for SVM training and testing. During the training and testing, the SVM parameters are optimized with the AAPSO technique, and in AAPSO, the acceleration coefficients are computed using the particle fitness values. The parameters in SVM, which are optimized by AAPSO, perform efficiently for both face and iris recognition. A comparative analysis between our proposed AAPSO-SVM and the PSO-SVM technique is presented.

Particle Acceleration in a Statistically Modeled Solar Active-Region Corona

Science.gov (United States)

Toutounzi, A.; Vlahos, L.; Isliker, H.; Dimitropoulou, M.; Anastasiadis, A.; Georgoulis, M.

2013-09-01

Elaborating a statistical approach to describe the spatiotemporally intermittent electric field structures formed inside a flaring solar active region, we investigate the efficiency of such structures in accelerating charged particles (electrons). The large-scale magnetic configuration in the solar atmosphere responds to the strong turbulent flows that convey perturbations across the active region by initiating avalanche-type processes. The resulting unstable structures correspond to small-scale dissipation regions hosting strong electric fields. Previous research on particle acceleration in strongly turbulent plasmas provides a general framework for addressing such a problem. This framework combines various electromagnetic field configurations obtained by magnetohydrodynamical (MHD) or cellular automata (CA) simulations, or by employing a statistical description of the field's strength and configuration with test particle simulations. Our objective is to complement previous work done on the subject. As in previous efforts, a set of three probability distribution functions describes our ad-hoc electromagnetic field configurations. In addition, we work on data-driven 3D magnetic field extrapolations. A collisional relativistic test-particle simulation traces each particle's guiding center within these configurations. We also find that an interplay between different electron populations (thermal/non-thermal, ambient/injected) in our simulations may also address, via a re-acceleration mechanism, the so called `number problem'. Using the simulated particle-energy distributions at different heights of the cylinder we test our results against observations, in the framework of the collisional thick target model (CTTM) of solar hard X-ray (HXR) emission. The above work is supported by the Hellenic National Space Weather Research Network (HNSWRN) via the THALIS Programme.

Particle acceleration by coronal and interplanetary shock waves

International Nuclear Information System (INIS)

Pesses, M.E.

1982-01-01

Utilizing many years of observation from deep space and near-earth spacecraft a theoretical understanding has evolved on how ions and electrons are accelerated in interplanetary shock waves. This understanding is now being applied to solar flare-induced shock waves propagating through the solar atmosphere. Such solar flare phenomena as gamma-ray line and neutron emissions, interplanetary energetic electron and ion events, and Type II and moving Type IV radio bursts appear understandable in terms of particle acceleration in shock waves

CAS CERN Accelerator School: Cyclotrons, linacs and their applications. Proceedings

International Nuclear Information System (INIS)

Turner, S.

1996-01-01

These proceedings present the lectures given at the eighth specialized course organized by the CERN Accelerator School (CAS), the topic this time being 'Cyclotrons, Linacs and Their Applications'. Following an introductory lecture on linacs, the fundamental features of electron, ion and induction linacs are described together with their RF systems and particle sources. Cyclotrons are then introduced followed by details of their different types, their magnet and RF design, and their injection and extraction systems, with a glance towards exotic and possible future machines. Chapters are then presented on the use of linacs and cyclotrons for medical, fission, fusion and material applications, as well as for isotope production. Finally, descriptions of the design of a radioisotope facility, the matching of accelerators to their task and the computational tools used in their design are included. (orig.)

CAS CERN Accelerator School: Cyclotrons, linacs and their applications. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Turner, S [ed.

1996-03-04

These proceedings present the lectures given at the eighth specialized course organized by the CERN Accelerator School (CAS), the topic this time being `Cyclotrons, Linacs and Their Applications`. Following an introductory lecture on linacs, the fundamental features of electron, ion and induction linacs are described together with their RF systems and particle sources. Cyclotrons are then introduced followed by details of their different types, their magnet and RF design, and their injection and extraction systems, with a glance towards exotic and possible future machines. Chapters are then presented on the use of linacs and cyclotrons for medical, fission, fusion and material applications, as well as for isotope production. Finally, descriptions of the design of a radioisotope facility, the matching of accelerators to their task and the computational tools used in their design are included. (orig.).

Particle Acceleration in Multiple Dissipation Regions

OpenAIRE

Arzner, Kaspar; Vlahos, Loukas

2004-01-01

The sharp magnetic discontinuities which naturally appear in solar magnetic flux tubes driven by turbulent photospheric motions are associated with intense currents. \\citet{Par83} proposed that these currents can become unstable to a variety of microscopic processes, with the net result of dramatically enhanced resistivity and heating (nanoflares). The electric fields associated with such ``hot spots'' are also expected to enhance particle acceleration. We test this hypothesis by exact relati...

Preparation of multilayer graphene sheets and their applications for particle accelerators

Science.gov (United States)

Tatami, Atsushi; Tachibana, Masamitsu; Yagi, Takashi; Murakami, Mutsuaki

2018-05-01

Multilayer graphene sheets were prepared by heat treatment of polyimide films at temperatures of up to 3000 °C. The sheets consist of highly oriented graphite layers with excellent mechanical robustness and flexibility. Key features of these sheets include their high thermal conductivity in the in-plane direction, good mechanical properties, and high carbon purity. The results suggest that the multilayer graphene sheets have great potential for charge stripping foils that persist even under the highest ion beam intensities irradiation and can be used for accelerator applications.

Particle acceleration via reconnection processes in the supersonic solar wind

International Nuclear Information System (INIS)

Zank, G. P.; Le Roux, J. A.; Webb, G. M.; Dosch, A.; Khabarova, O.

2014-01-01

An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized small-scale reconnection processes, essentially between quasi-2D interacting magnetic islands. Charged particles trapped in merging magnetic islands can be accelerated by the electric field generated by magnetic island merging and the contraction of magnetic islands. We derive a gyrophase-averaged transport equation for particles experiencing pitch-angle scattering and energization in a super-Alfvénic flowing plasma experiencing multiple small-scale reconnection events. A simpler advection-diffusion transport equation for a nearly isotropic particle distribution is derived. The dominant charged particle energization processes are (1) the electric field induced by quasi-2D magnetic island merging and (2) magnetic island contraction. The magnetic island topology ensures that charged particles are trapped in regions where they experience repeated interactions with the induced electric field or contracting magnetic islands. Steady-state solutions of the isotropic transport equation with only the induced electric field and a fixed source yield a power-law spectrum for the accelerated particles with index α = –(3 + M A )/2, where M A is the Alfvén Mach number. Considering only magnetic island contraction yields power-law-like solutions with index –3(1 + τ c /(8τ diff )), where τ c /τ diff is the ratio of timescales between magnetic island contraction and charged particle diffusion. The general solution is a power-law-like solution with an index that depends on the Alfvén Mach number and the timescale ratio τ diff /τ c . Observed power-law distributions of energetic particles observed in the quiet supersonic solar wind at 1 AU may be a consequence of particle acceleration associated with dissipative small-scale reconnection processes in a turbulent plasma, including the widely reported c –5 (c particle speed) spectra observed by Fisk and Gloeckler

Production of neutrons in particle accelerators: a PNRI safety concern

International Nuclear Information System (INIS)

Garcia, Corazon M.; Cayabo, Lynette B.; Artificio, Thelma P.; Melendez, Johnylen V.; Piquero, Myrna E.; Parami, Vangeline K.

2002-09-01

In the safety assessment made for the first cyclotron facility in the Philippines, that is the cyclotron in the P.E.T. (Positron Emission Tomography) center of the St. Luke's Medical Center, the concern on the production of neutrons associated with the operation of particle accelerators has been identified. This takes into consideration the principles in the operation of particle accelerators and the associated production of neutrons resulting from their operation, the hazards and risks in their operation. The Bureau of Health Devices and Technology (BHDT) of the Department of Health in the Philippines regulates and controls the presently existing six (6) linear accelerators distributed in different hospitals in the country, being classified as x-ray producing devices. From the results of this study, it is evident that the production of neutrons from the operation of accelerators, produces neutrons and that activation due to neutrons can form radioactive materials. The PNRI (Philippine Nuclear Research Institute) being mandated by law to regulate and control any equipment or devices producing or utilizing radioactive materials should take the proper steps to subject all accelerator facilities and devices in the Philippines such as linear accelerators under its regulatory control in the same manner as it did with the first cyclotron in the country. (Author)

3rd International Conference on Particle Physics Beyond the Standard Model : Accelerator, Non-Accelerator and Space Approaches

CERN Document Server

Beyond The Desert 2002

2003-01-01

The third conference on particle physics beyond the Standard Model (BEYOND THE DESERT'02 - Accelerator, Non-accelerator and Space Approaches) was held during 2--7 June, 2002 at the Finish town of Oulu, almost at the northern Arctic Circle. It was the first of the BEYOND conference series held outside Germany (CERN Courier March 2003, pp. 29-30). Traditionally the Scientific Programme of BEYOND conferences, brought into life in 1997 (see CERN Courier, November 1997, pp.16-18), covers almost all topics of modern particle physics (see contents).

Advanced Accelerator Concepts

Science.gov (United States)

Siemann, Robert

1998-04-01

Current particle accelerators rely on conventional or superconducting radio frequency cavities to accelerate beams of protons or electrons for nuclear and particle research and for medical and materials science studies. New methods for achieving larger accelerating gradients have been proposed and are being studied. These include the use of high power lasers, laser driven plasmas, wake fields generated by intense low energy beams, and millimeter wavelength EM structures. The studies to date, and the prospects for practical applications of these new ideas will be discussed.

Additional acceleration of solar-wind particles in current sheets of the heliosphere

Directory of Open Access Journals (Sweden)

V. Zharkova

2015-04-01

Full Text Available Particles of fast solar wind in the vicinity of the heliospheric current sheet (HCS or in a front of interplanetary coronal mass ejections (ICMEs often reveal very peculiar energy or velocity profiles, density distributions with double or triple peaks, and well-defined streams of electrons occurring around or far away from these events. In order to interpret the parameters of energetic particles (both ions and electrons measured by the WIND spacecraft during the HCS crossings, a comparison of the data was carried out with 3-D particle-in-cell (PIC simulations for the relevant magnetic topology (Zharkova and Khabarova, 2012. The simulations showed that all the observed particle-energy distributions, densities, ion peak velocities, electron pitch angles and directivities can be fitted with the same model if the heliospheric current sheet is in a status of continuous magnetic reconnection. In this paper we present further observations of the solar-wind particles being accelerated to rather higher energies while passing through the HCS and the evidence that this acceleration happens well before the appearance of the corotating interacting region (CIR, which passes through the spacecraft position hours later. We show that the measured particle characteristics (ion velocity, electron pitch angles and the distance at which electrons are turned from the HCS are in agreement with the simulations of additional particle acceleration in a reconnecting HCS with a strong guiding field as measured by WIND. A few examples are also presented showing additional acceleration of solar-wind particles during their passage through current sheets formed in a front of ICMEs. This additional acceleration at the ICME current sheets can explain the anticorrelation of ion and electron fluxes frequently observed around the ICME's leading front. Furthermore, it may provide a plausible explanation of the appearance of bidirectional "strahls" (field-aligned most energetic

Next-generation particle accelerators for frontline research and wide-ranging applications in India - how to realize them?

International Nuclear Information System (INIS)

Bhandari, R.K.; Roy, Amit

2015-01-01

Several modern accelerator facilities have been set up in India for basic and applied research during the past 5 decades. Indian scientists have been able to carry out excellent accelerator-based research at these as well as international facilities. Applications of accelerators in healthcare and industry have also grown in recent years. There is a strong realization now, at all levels, that a quantum jump needs to be given to the field of accelerator science and technology in India to fulfil the aspirations of the research community to be at par internationally in our areas of strength. Applications in industry and healthcare also have to grow substantially to benefit the common man. In this article an analysis of the methodology and logic behind the evolution of our accelerator programme has been presented. More importantly, recommendations have been given for gainfully implementing a rather ambitious programme that is proposed to be taken up in the next few decades. (author)

Acceleration statistics of finite-sized particles in turbulent flow: the role of Faxen forces

OpenAIRE

Calzavarini, Enrico; Volk, Romain; Bourgoin, Mickael; Leveque, Emmanuel; Pinton, Jean-Francois; Toschi, Federico

2008-01-01

International audience; The dynamics of particles in turbulence when the particle size is larger than the dissipative scale of the carrier flow are studied. Recent experiments have highlighted signatures of particles' finiteness on their statistical properties, namely a decrease of their acceleration variance, an increase of correlation times (at increasing the particles size) and an independence of the probability density function of the acceleration once normalized to their variance. These ...

The overview and history of permanent magnet devices in accelerator technology

International Nuclear Information System (INIS)

Kraus, R.H.

1994-01-01

This paper looks at the early history of accelerator development with a particular focus on the important discoveries that opened the door for the application of permanent-magnet materials to this area of science. Researchers began to use permanent-magnet materials in particle accelerators soon after the invention of the alternating gradient principle, that showed magnetic fields could be used to control the transverse envelope of charged-particle beams. Since that time, permanent-magnet materials have found wide application in the modern charged particle accelerator. A brief history of permanent-magnet use in accelerator physics and technology is outlined, some of the general design considerations are presented, and several material properties of concern for particle accelerator applications are discussed

The overview and history of permanent magnet devices in accelerator technology

International Nuclear Information System (INIS)

Kraus, R.H. Jr.

1993-01-01

This paper reviews the early history of accelerator development with a particular focus on the important discoveries that opened the door for the application of permanent-magnet materials to this area of science. Researchers began to use permanent-magnet materials in particle accelerators soon after the invention of the alternating gradient principle, that showed magnetic fields could be used to control the transverse envelope of charged-particle beams. Since that time, permanent-magnet materials have found wide application in the modern charged particle accelerator. The history of permanent-magnet use in accelerator physics and technology is outlined, general design considerations are presented, and material properties of concern for particle accelerator applications are discussed

Technical training: AXEL-2009 - Introduction to Particle Accelerators

CERN Multimedia

HR Department

2009-01-01

CERN Technical Training 2009: Learning for the LHC! AXEL-2009 is a course series on particle accelerators, given at CERN within the framework of the 2009 Technical Training Program. Known in the past as the PS Complex Operation Course (or the ‘PS Shutdown Course’), the general accelerator physics module as been organized since 2003 as a joint venture between the AB Department and Technical Training Service, and is open to a wider CERN community. The AXEL-2009 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is also open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge of accelerators. However, some basic knowledge of trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) from 19 to 23 January 2009, and will be given i...

Technical Training: AXEL-2005 - Introduction to Particle Accelerators

CERN Multimedia

Monique Duval

2005-01-01

CERN Technical Training 2005: Learning for the LHC! AXEL-2005 is a course series on particle accelerators, given at CERN within the framework of the 2005 Technical Training Programme. Known in the past as the PS Complex Operation Course (or the 'PS Shutdown Course', now AB/OP), the general accelerator physics section is organised since 2003 as a joint venture between the AB department and Technical Training, and is open to a wider CERN community. The AXEL-2005 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to all people (technicians, engineers, physicists) interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course will be given in French on course supports in English; questions and answers possible in both languages. AXEL-2005 - I...

Technical training: AXEL-2012 - Introduction to Particle Accelerators

CERN Multimedia

HR Department

2011-01-01

CERN Technical Training 2012: Learning for the LHC! AXEL-2012 is a course series on particle accelerators, given at CERN within the framework of the Technical Training Program. Being part of BE Department’s Operation Group Shutdown Lecture series, the general accelerator physics module is organized since 2003 as a joint venture between the BE Department and Technical Training, and is open to a wider CERN community. The AXEL-2012 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) from the 16th – 20th of January 2012, and given in English with ...

Technical training: AXEL-2011 - Introduction to Particle Accelerators

CERN Multimedia

HR Department

2010-01-01

CERN Technical Training 2011: Learning for the LHC! AXEL-2011 is a course series on particle accelerators, given at CERN within the framework of the 2011 Technical Training Program. As part of the BE Department’s Operation Group Shutdown Lecture series, the general accelerator physics module has been organized since 2003 as a joint venture between the BE Department and Technical Training, and is open to a wider CERN community. The AXEL-2011 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is also open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge of accelerators. However, some basic knowledge of trigonometry, matrices and differential equations, and some basic knowledge of magnetism would be an advantage. The series will be composed of 10 one-hour courses (Monday 10.01.2011 – Fri 14.01.2011, from 09:00 to 10:30 and from 14:00 to 15:...

Technical training: AXEL-2006 - Introduction to Particle Accelerators

CERN Multimedia

Davide Vitè

2006-01-01

CERN Technical Training 2006: Learning for the LHC! AXEL-2006 is a course series on particle accelerators, given at CERN within the framework of the 2006 Technical Training Programme. Known in the past as the PS Complex Operation Course (or the 'PS Shutdown Course'), the general accelerator physics module is organised since 2003 as a joint venture between the AB department and Technical Training, and is open to a wider CERN community. The AXEL-2006 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) during the week 6-10 February March 2006, and given in English...

Technical Training: AXEL-2005: Introduction to Particle Accelerators

CERN Multimedia

Monique Duval

2005-01-01

CERN Technical Training 2005: Learning for the LHC! AXEL-2005 is a course series on particle accelerators, given at CERN within the framework of the 2005 Technical Training Programme. Known in the past as the PS Complex Operation Course (or the 'PS Shutdown Course', now AB/OP), the general accelerator physics section is organised since 2003 as a joint venture between the AB department and Technical Training, and is open to a wider CERN community. The AXEL-2005 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to all people (technicians, engineers, physicists) interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) during the week 14-18 March 2005, given in Fr...

Technical training: AXEL-2009 - Introduction to Particle Accelerators

CERN Multimedia

HR Department

2008-01-01

CERN Technical Training 2009: Learning for the LHC! AXEL-2009 is a course series on particle accelerators, given at CERN within the framework of the 2009 Technical Training Program. Known in the past as the PS Complex Operation Course (or the ‘PS Shutdown Course’), the general accelerator physics module is organized since 2003 as a joint venture between the AB department and Technical Training, and is open to a wider CERN community. The AXEL-2009 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) from the 19th – 23rd of January 2009, and given in English with...

Technical training: AXEL-2010 - Introduction to particle accelerators

CERN Multimedia

HR Department

2010-01-01

CERN Technical Training 2010: Learning for the LHC! AXEL-2010 is a course series on particle accelerators, given at CERN within the framework of the 2010 Technical Training Program. Known in the past as the PS Complex Operation Course (or the ‘PS Shutdown Course’), the general accelerator physics module is organized since 2003 as a joint venture between the BE department and Technical Training, and is open to a wider CERN community. The AXEL-2010 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) from the 1st – 5th of February 201...

Accelerator development for medical applications

International Nuclear Information System (INIS)

Tanabe, Eiji

2007-01-01

Electron linear accelerators have been widely used in medical applications, especially in radiation therapy for cancer treatment. There are more than 7,000 medical electron linear accelerators in the world, treating over 250,000 patients per day. This paper reviews the current status of accelerator applications and technologies in radiation therapy, and presents the anticipated requirements for advanced radiation therapy technology in the foreseeable future. (author)

Measuring Lagrangian accelerations using an instrumented particle

International Nuclear Information System (INIS)

Zimmermann, R; Fiabane, L; Volk, R; Pinton, J-F; Gasteuil, Y

2013-01-01

Accessing and characterizing a flow imposes a number of constraints on the employed measurement techniques; in particular, optical methods require transparent fluids and windows in the vessel. Whereas one can adapt the apparatus, fluid and methods in the laboratory to these constraints, this is hardly possible for industrial mixers. In this paper, we present a novel measurement technique which is suitable for opaque or granular flows: consider an instrumented particle, which continuously transmits the force/acceleration acting on it as it is advected in a flow. Its density is adjustable for a wide range of fluids and because of its small size and its wireless data transmission, the system can be used both in industrial and in scientific mixers, allowing for a better understanding of the flow within. We demonstrate the capabilities and precision of the particle by comparing its transmitted acceleration to alternative measurements, in particular in the case of a turbulent von Kármán flow. Our technique proves to be an efficient and fast tool to characterize flows. (paper)

Space experiments with particle accelerators: SEPAC

International Nuclear Information System (INIS)

Obayashi, T.

1978-01-01

In this paper, the program of the space experiments with particle accelerators (SEPAC) is described. The SEPAC is to be prepared for the Space Shuttle/First Spacelab Mission. It is planned in the SEPAC to carry out the active and interactive experiments on and in the Earth's ionosphere and magnetosphere. It is also intended to make an initial performance test for the overall program of Spacelab/SEPAC experiments. The instruments to be used are electron beam accelerators, MPD arcjects, and associated diagnostic equipments. The main scientific objectives of the experiments are Vehicle Charge Neutralization, Beam Plasma Physics, and Beam Atmosphere Interactions. The SEPAC system consists of the following subsystems. Those are accelerators, monitoring and diagnostic equipments, and control and data management equipments. The SEPAC functional objectives for experiment operations are SEPAC system checkout, EBA firing test, MPD firing test, electron beam experiments, plasma beam propagation, artificial aurora excitation, equatorial aerochemistry, electron echo experiment, E parallel B experiment, passive experiments, SEPAC system deactivation, and battery charging. Most experiment procedures are carried out by the pre-set computer program. (Kato, T.)

Course Notes: United States Particle Accelerator School Beam Physics with Intense Space-Charge

International Nuclear Information System (INIS)

Barnard, J.J.; Lund, S.M.

2008-01-01

The purpose of this course is to provide a comprehensive introduction to the physics of beams with intense space charge. This course is suitable for graduate students and researchers interested in accelerator systems that require sufficient high intensity where mutual particle interactions in the beam can no longer be neglected. This course is intended to give the student a broad overview of the dynamics of beams with strong space charge. The emphasis is on theoretical and analytical methods of describing the acceleration and transport of beams. Some aspects of numerical and experimental methods will also be covered. Students will become familiar with standard methods employed to understand the transverse and longitudinal evolution of beams with strong space charge. The material covered will provide a foundation to design practical architectures. In this course, we will introduce you to the physics of intense charged particle beams, focusing on the role of space charge. The topics include: particle equations of motion, the paraxial ray equation, and the Vlasov equation; 4-D and 2-D equilibrium distribution functions (such as the Kapchinskij-Vladimirskij, thermal equilibrium, and Neuffer distributions), reduced moment and envelope equation formulations of beam evolution; transport limits and focusing methods; the concept of emittance and the calculation of its growth from mismatches in beam envelope and from space-charge non-uniformities using system conservation constraints; the role of space-charge in producing beam halos; longitudinal space-charge effects including small amplitude and rarefaction waves; stable and unstable oscillation modes of beams (including envelope and kinetic modes); the role of space charge in the injector; and algorithms to calculate space-charge effects in particle codes. Examples of intense beams will be given primarily from the ion and proton accelerator communities with applications from, for example, heavy-ion fusion, spallation

Analysis of secondary particle behavior in multiaperture, multigrid accelerator for the ITER neutral beam injector.

Science.gov (United States)

Mizuno, T; Taniguchi, M; Kashiwagi, M; Umeda, N; Tobari, H; Watanabe, K; Dairaku, M; Sakamoto, K; Inoue, T

2010-02-01

Heat load on acceleration grids by secondary particles such as electrons, neutrals, and positive ions, is a key issue for long pulse acceleration of negative ion beams. Complicated behaviors of the secondary particles in multiaperture, multigrid (MAMuG) accelerator have been analyzed using electrostatic accelerator Monte Carlo code. The analytical result is compared to experimental one obtained in a long pulse operation of a MeV accelerator, of which second acceleration grid (A2G) was removed for simplification of structure. The analytical results show that relatively high heat load on the third acceleration grid (A3G) since stripped electrons were deposited mainly on A3G. This heat load on the A3G can be suppressed by installing the A2G. Thus, capability of MAMuG accelerator is demonstrated for suppression of heat load due to secondary particles by the intermediate grids.

Improved techniques of impedance calculation and localization in particle accelerators

CERN Document Server

Biancacci, Nicolò; Migliorati, Mauro; Métral, Elias; Salvant, Benoit

In this thesis we mainly focus on particle accelerators applied to high energy physics research where a fundamental parameter, the luminosity, is maximized in order to increase the rate of particle collisions useful to particle physicists. One way to increase this parameter is to increase the intensity of the circulating beams which is limited by the onset of collective effects that may drive the beam unstable and eventually provoke beam losses or reduce the beam quality required by the particle physics experiments. One major cause of collective effects is the beam coupling impedance, a quantity that quantifies the effect of the fields scattered by a beam passing through any accelerator device. The development of an impedance budget is required in those machines that are planning substantial upgrades as shown in this thesis for the CERN PS case. The main source of impedance in the CERN LHC are the collimators. Within an impedance reduction perspective, in order to reach the goals of the planned upgrades, it ...

Determination of Beam Intensity and Position in a Particle Accelerator

CERN Document Server

Kasprowicz, Grzegorz; Raich, Uli

2011-10-04

A subject of the thesis is conception, design, implementation, tests and deployment of new position measurement system of particle bunch in the CERN PS circular accelerator. The system is based on novel algorithms of particle position determination. The Proton Synchrotron accelerator (PS), installed at CERN†, although commissioned in 1959, still plays a central role in the production of beams for the Antiproton Decelerator, Super Proton Synchrotron, various experimental areas and for the Large Hadron Collider (LHC)‡. The PS produces beams of different types of particles, mainly protons, but also various species of ions. Almost all these particle beams pass through the PS. The quality of the beams delivered to the LHC has a direct impact on the effective luminosity, and therefore the performance of the instrumentation of the PS is of great importance. The old trajectory and orbit measurement system of the PS is dated back to 1988 and no longer fulfilled present day requirements. It used 40 beam posi...

Determination of beam intensity and position in a particle accelerator

CERN Document Server

Kasprowicz, G

2011-01-01

A subject of the thesis is conception, design, implementation, tests and deployment of new position measurement system of particle bunch in the CERN PS circular accelerator. The system is based on novel algorithms of particle position determination. The Proton Synchrotron accelerator (PS), installed at CERN, although commissioned in 1959, still plays a central role in the production of beams for the Antiproton Decelerator, Super Proton Synchrotron, various experimental areas and for the Large Hadron Collider (LHC). The PS produces beams of different types of particles, mainly protons, but also various species of ions. Almost all these particle beams pass through the PS. The quality of the beams delivered to the LHC has a direct impact on the effective luminosity, and therefore the performance of the instrumentation of the PS is of great importance. The old trajectory and orbit measurement system of the PS is dated back to 1988 and no longer fulfilled present day requirements. It used 40 beam position monitors...

Propositions for a PDF model based on fluid particle acceleration

International Nuclear Information System (INIS)

Minier, J.P.; Pozorski, J.

1997-05-01

This paper describes theoretical propositions to model the acceleration of a fluid particle in a turbulent flow. Such a model is useful for the PDF approach to turbulent reactive flows as well as for the Lagrangian modelling of two-phase flows. The model developed here draws from ideas already put forward by Sawford but which are generalized to the case of non-homogeneous flows. The model is built so as to revert continuously to Pope's model, which uses a Langevin equation for particle velocities, when the Reynolds number becomes very high. The derivation is based on the technique of fast variable elimination. This technique allow a careful analysis of the relations between different levels of modelling. It also allows to address certain problems in a more rigorous way. In particular, application of this technique shows that models presently used can in principle simulate bubbly flows including the pressure-gradient and added-mass forces. (author)

An Expert System For Tuning Particle-Beam Accelerators

Science.gov (United States)

Lager, Darrel L.; Brand, Hal R.; Maurer, William J.; Searfus, Robert M.; Hernandez, Jose E.

1989-03-01

We have developed a proof-of-concept prototype of an expert system for tuning particle beam accelerators. It is designed to function as an intelligent assistant for an operator. In its present form it implements the strategies and reasoning followed by the operator for steering through the beam transport section of the Advanced Test Accelerator at Lawrence Livermore Laboratory's Site 300. The system is implemented in the language LISP using the Artificial Intelligence concepts of frames, daemons, and a representation we developed called a Monitored Decision Script.

Linear induction accelerators

International Nuclear Information System (INIS)

Briggs, R.J.

1986-06-01

The development of linear induction accelerators has been motivated by applications requiring high-pulsed currents of charged particles at voltages exceeding the capability 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, but the 50-MeV, 10-kA Advanced Test Accelerator (ATA) at LLNL is the highest voltage machine in existence at this time. The advent of magnetic pulse power systems makes sustained operation at high-repetition rates practical, and this capability for high-average power is very likely to open up many new applications of induction machines in the future. This paper surveys the US induction linac technology with primary emphasis on electron machines. A simplified description of how induction machines couple energy to the electron beam is given, to illustrate many of the general issues that bound the design space of induction linacs

Safety and regulatory aspects of accelerators

International Nuclear Information System (INIS)

Singh, Pitamber

2017-01-01

Particle accelerators are devices that produce beams of energetic ions and electrons which have applications in various fields. Historically, particle accelerators were developed for nuclear physics research. Although the particle physics community is still the main user group, joined by others. There is also an increasing interest in radiation therapy in the medical world and industry has been a long-time user of ion implantation an many other applications. Accelerators are also being used for nuclear energy generation using Thorium and waste management through incineration of minor actinides using accelerator driven sub-critical reactor system (ADS). This is of great interest to India as it has large resources of good quality thorium. The ADS are considered to be an inherently safe system as the reactor is sub-critical. However, ADS require high energy and high current proton beams which involve complex technologies. Accelerators deliver energy to the charged particles by means of electromagnetic fields. Depending on how the electric and magnetic fields are used, the accelerators can be grouped in three categories namely electrostatic or DC accelerators, RF accelerators and colliding rings. In DC accelerators, particles pass through a high voltage and gain energy given by E= qV where q is the charge of ion and V is the voltage tough which ion pass. In order to sustain high voltage accelerator column section is housed inside a pressure vessel which is filled with gas, normally SF_6, at high pressure (100 -150 psig)

Formation of spectrum of accelerated particles and the hydromagnetic turbulence in the variable magnetic field

International Nuclear Information System (INIS)

Savane, Y. Sy; Diaby, I.; Faza Barry, M.; Lomonossov, V.

2002-11-01

We study the acceleration of charged particles by the variable magnetic field. The study is based on the determination of spectrum of accelerated particles and the spectrum of hydro magnetic turbulence. We plan the self-consistent system of equation and we also find out the solution of the system for the spectrum of particles and hydro magnetic turbulence with the conditions of effective acceleration in the cosmic space of solar system. (author)

Simulations and measurements of coupling impedance for modern particle accelerator devices

CERN Document Server

AUTHOR|(CDS)2158523; Biancacci, Nicolò; Mostacci, Andrea

In this document it has been treated the study of the coupling impedance in modern devices, already installed or not, in different particle accelerators. In the specific case: • For a device in-phase of project, several simulations for impedance calculation have been done. • For a component already realized and used, measurements of coupling impedance value have been done. Simulations are used to determine the impact of the interconnect between to magnets, designed for the future particle accelerator FCC, on the overall impedance of the machine which is about 100 km long. In particular has been done a check between theory, simulations and measurements of components already built, allowing a better and deeper study of the component we have analysed. Controls that probably will be helpful to have a clear guideline in future works. The measurements instead concern in an existing component that was already used in LHC, the longest particle accelerator ever realised on the planet, 27 km long. The coupling impe...

The appreciation of stochastic motion in particle accelerators

International Nuclear Information System (INIS)

Symon, Keith; Sessler, Andrew

2003-01-01

A description is given of the analytic and numerical work, performed from July 1955 through August 1956, so as to develop, and then study, the process of making intense proton beams, suitable for colliding beams. It is shown how this investigation led, in a most natural way, to the realization that stochasticity can arise in a simple Hamiltonian system. Furthermore, the criterion for the onset of stochasticity was understood, and carefully studied, in two different situations. The first situation was the proposed (and subsequently used) ''stacking process'' for developing an intense beam, where stochasticity occurs as additional particles are added to the intense circulating beam. The second situation occurs when one seeks to develop ''stochastic accelerators'' in which particles are accelerated (continuously) by a collection of radio frequency systems. It was in the last connection that the well-known criterion for stochasticity, resonance overlap, was obtained

Development of a charged particle multidetector and application to physics at the Vivitron accelerator

International Nuclear Information System (INIS)

Belier, G.

1994-05-01

The charged particle multidetector ICARE is an apparatus designed for the Vivitron accelerator, with the aim to study both heavy ions reaction mechanisms and the structure of the nuclei. It will be able to work independently with its own electronic and acquisition system as well as in association with other types of multidetectors (Eurogam, Demon, ...). The development of ICARE is based on compactness and modularity criteria and takes into account the expected multiplicities and energies of the particles to be detected. It is composed of 48 compact telescopes of low energy threshold, 8 of them being heavy ion telescopes (Z 147 Gd superdeformed states of highest angular momenta. In the gamma ray spectra detected by the Eurogam array in coincidence with fission fragments, a positive contribution corresponding to energy differences are observed, which are consistent with the emission by superdeformed states. (from author) 64 figs., 12 tabs., 91 refs

New developments in particle acceleration techniques. Proceedings. Vol. 2

International Nuclear Information System (INIS)

Turner, S.

1987-01-01

A Workshop organised jointly by the European Committee for Future Accelerators (ECFA), the CERN Accelerator School (CAS), the Institut National de Physique Nucleaire et de Physique des Particules (IN2P3), the Institut pour la Recherche Fondamentale/Commissariat a l'Energie Atomique (IRF/CEA) and the European Physical Society (EPS) was held at the Laboratoire de l'Accelerateur Lineaire (LAL), Orsay, from 29 June to 4 July 1987. Its purpose was to review current experimental and theoretical developments in charged-particle accelerator techniques and to address problems related to future very-high-energy machines. These proceedings contain the great majority of the papers presented at the Workshop, the corresponding questions and answers, and the round-table discussion. The principal topics were semi-conventional high-frequency linacs, transformer acceleration mechanisms, acceleration using plasma, e + e - sources, including low-emittance production and preservation, final focus and interaction point, and other new ideas. Among the latter were open accelerating structures, crystal X-ray accelerators, ferroelectrics, and acceleration using lasers. (orig.)

New developments in particle acceleration techniques. Proceedings. Vol. 1

International Nuclear Information System (INIS)

Turner, S.

1987-01-01

A Workshop organised jointly by the European Committee for Future Accelerators (ECFA), the CERN Accelerator School (CAS), the Institut National de Physique Nucleaire et de Physique des Particules (IN2P3), the Institut pour la Recherche Fondamentale/Commissariat a l'Energie Atomique (IRF/CEA) and the European Physical Society (EPS) was held at the Laboratoire de l'Accelerateur Lineaire (LAL), Orsay, from 29 June to 4 July 1987. Its purpose was to review current experimental and theoretical developments in charged-particle accelerator techniques and to address problems related to future very-high-energy machines. These proceedings contain the great majority of the papers presented at the Workshop, the corresponding questions and answers, and the round-table discussion. The principal topics were semi-conventional high-frequency linacs, transformer acceleration mechanisms, acceleration using plasma, e + e - sources including low-emittance production and preservation, final focus and interaction point, and other new ideas. Among the latter were open accelerating structures, crystal X-ray accelerators, ferroelectrics, and acceleration using lasers. (orig.)

The United States Particle Accelerator School: Educating the Next Generation of Accelerator Scientists and Engineers

International Nuclear Information System (INIS)

Barletta, William A.

2009-01-01

Only a handful of universities in the US offer any formal training in accelerator science. The United States Particle Accelerator School (USPAS) is National Graduate Educational Program that has developed a highly successful educational paradigm that, over the past twenty-years, has granted more university credit in accelerator/beam science and technology than any university in the world. Sessions are held twice annually, hosted by major US research universities that approve course credit, certify the USPAS faculty, and grant course credit. The USPAS paradigm is readily extensible to other rapidly developing, cross-disciplinary research areas such as high energy density physics.

The United States Particle Accelerator School: Educating the next generation of accelerator scientists and engineers

International Nuclear Information System (INIS)

Barletta, William A.

2008-01-01

Only a handful of universities in the US offer any formal training in accelerator science. The United States Particle Accelerator School (USPAS) is National Graduate Educational Program that has developed a highly successful educational paradigm that, over the past twenty-years, has granted more university credit in accelerator / beam science and technology than any university in the world. Sessions are held twice annually, hosted by major US research universities that approve course credit, certify the USPAS faculty, and grant course credit. The USPAS paradigm is readily extensible to other rapidly developing, crossdisciplinary research areas such as high energy density physics

Load management strategy for Particle-In-Cell simulations in high energy particle acceleration

Energy Technology Data Exchange (ETDEWEB)

Beck, A., E-mail: beck@llr.in2p3.fr [Laboratoire Leprince-Ringuet, École polytechnique, CNRS-IN2P3, Palaiseau 91128 (France); Frederiksen, J.T. [Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø (Denmark); Dérouillat, J. [CEA, Maison de La Simulation, 91400 Saclay (France)

2016-09-01

In the wake of the intense effort made for the experimental CILEX project, numerical simulation campaigns have been carried out in order to finalize the design of the facility and to identify optimal laser and plasma parameters. These simulations bring, of course, important insight into the fundamental physics at play. As a by-product, they also characterize the quality of our theoretical and numerical models. In this paper, we compare the results given by different codes and point out algorithmic limitations both in terms of physical accuracy and computational performances. These limitations are illustrated in the context of electron laser wakefield acceleration (LWFA). The main limitation we identify in state-of-the-art Particle-In-Cell (PIC) codes is computational load imbalance. We propose an innovative algorithm to deal with this specific issue as well as milestones towards a modern, accurate high-performance PIC code for high energy particle acceleration.

Contributions to the 1999 particle accelerator conference

Energy Technology Data Exchange (ETDEWEB)

Bernard, M. [Laboratoire de l' Accelerateur Lineaire, 91 - Orsay (France); Fartoukh, S.; Jablonka, M.; Joly, J.M.; Lalot, M.; Magne, C.; Napoly, O. [CEA/Saclay, 91 - Gif sur Yvette (France); Baboi, N.; Schreiber, S.; Simrock, S.; Weise, H. [DESY, Hamburg (Germany)

2000-06-01

This document puts together the 10 contributions of the laboratory to the 1999 particle accelerator conference. The titles of the papers are: 1) Evidence for a strongly coupled dipole mode with insufficient damping in the first accelerating module of the TESLA test facility (TTF); 2) An alternative scheme for stiffening superconducting RF cavities by plasma spraying; 3) A laser triggered electron source for pulsed radiolysis; 4) A cure for the energy spread increasing related bunch lengthening in electron storage rings; 5) Single bunch longitudinal instabilities in proton storage rings; 6) Analytical investigation on the halo formation in space charge dominated beams; 7) Analytical investigation on the dynamic apertures of circular accelerators; 8) The intrinsic upper limit to the beam energy of an electron-positron circular collider; 9) Coaxial disc windows for a high power superconducting cavity input coupler; and 10) RF pulsed tests on 3 GHz niobium cavities.

Contributions to the 1999 particle accelerator conference

International Nuclear Information System (INIS)

Bernard, M.; Fartoukh, S.; Jablonka, M.; Joly, J.M.; Lalot, M.; Magne, C.; Napoly, O.; Baboi, N.; Schreiber, S.; Simrock, S.; Weise, H.

2000-06-01

This document puts together the 10 contributions of the laboratory to the 1999 particle accelerator conference. The titles of the papers are: 1) Evidence for a strongly coupled dipole mode with insufficient damping in the first accelerating module of the TESLA test facility (TTF); 2) An alternative scheme for stiffening superconducting RF cavities by plasma spraying; 3) A laser triggered electron source for pulsed radiolysis; 4) A cure for the energy spread increasing related bunch lengthening in electron storage rings; 5) Single bunch longitudinal instabilities in proton storage rings; 6) Analytical investigation on the halo formation in space charge dominated beams; 7) Analytical investigation on the dynamic apertures of circular accelerators; 8) The intrinsic upper limit to the beam energy of an electron-positron circular collider; 9) Coaxial disc windows for a high power superconducting cavity input coupler; and 10) RF pulsed tests on 3 GHz niobium cavities

Evaluation of a new method of RF power coupling to acceleration cavity of charged particles accelerators

Directory of Open Access Journals (Sweden)

A M Poursaleh

2017-08-01

Full Text Available In this paper, the feasibility studty of a new method of RF power coupling to acceleration cavity of charged particles accelerator will be evaluated. In this method a slit is created around the accelerator cavity, and RF power amplifier modules is connected directly to the acceleration cavity. In fact, in this design, the cavity in addition to acting as an acceleration cavity, acts as a RF power combiner. The benefits of this method are avoiding the use of RF vacuum tubes, transmission lines, high power combiner and coupler. In this research, cylindrical and coaxial cavities were studied, and a small sample coaxial cavity is build by this method. The results of the resarch showed that compact, economical and safe RF accelerators can be achieved by the proposed method

Experimental Insights into the Mechanisms of Particle Acceleration by Shock Waves

Science.gov (United States)

Scolamacchia, T.; Scheu, B.; Dingwell, D. B.

2011-12-01

The generation of shock waves is common during explosive volcanic eruptions. Particles acceleration following shock wave propagation has been experimentally observed suggesting the potential hazard related to this phenomenon. Experiments and numerical models focused on the dynamics of formation and propagation of different types of shock waves when overpressurized eruptive mixtures are suddenly released in the atmosphere, using a pseudo-gas approximation to model those mixtures. Nevertheless, the results of several studies indicated that the mechanism of coupling between a gas and solid particles is valid for a limited grain-size range, which at present is not well defined. We are investigating particle acceleration mechanisms using a vertical shock tube consisting of a high-pressure steel autoclave (450 mm long, 28 mm in diameter), pressurized with argon, and a low-pressure 140 mm long acrylic glass autoclave, with the same internal diameter of the HP reservoir. Shock waves are generated by Ar decompression at atmospheric pressures at Pres/Pamb 100:1 to 150:1, through the failure of a diaphragm. Experiments were performed either with empty autoclave or suspending solid analogue particles 150 μm in size inside the LP autoclave. Incident Mach number varied from 1.7 to 2.1. Absolute and relative pressure sensors monitored P histories during the entire process, and a high-speed camera recorded particles movement at 20,000 to 30,000 fps. Preliminary results indicate pressure multiplication at the contact between shock waves and the particles in a time lapse of 100s μs, suggesting a possible different mechanism with respect to gas-particle coupling for particle acceleration.

A theory of two-beam acceleration of charged particles in a plasma waveguide

International Nuclear Information System (INIS)

Ostrovsky, A.O.

1993-11-01

The progress made in recent years in the field of high-current relativistic electron beam (REB) generation has aroused a considerable interest in studying REB potentialities for charged particle acceleration with a high acceleration rate T = 100MeV/m. It was proposed, in particular, to employ high-current REB in two-beam acceleration schemes (TBA). In these schemes high current REB (driving beam) excites intense electromagnetic waves in the electrodynamic structure which, in their turn, accelerate particles of the other beam (driven beam). The TBA schemes can be divided into two groups. The first group includes the schemes, where the two beams (driving and driven) propagate in different electrodynamic structures coupled with each other through the waveguides which ensure the microwave power transmission to accelerate driven beam particles. The second group includes the TBA schemes, where the driving and driven beams propagate in one electrodynamic structure. The main aim of this work is to demonstrate by theory the possibility of realizing effectively the TBA scheme in the plasma waveguide. The physical model of the TBA scheme under study is formulated. A set of equations describing the excitation of RF fields by a high-current REB and the acceleration of driven beam electrons is also derived. Results are presented on the the linear theory of plasma wave amplification by the driving beam. The range of system parameters, at which the plasma-beam instability develops, is defined. Results of numerical simulation of the TBA scheme under study are also presented. The same section gives the description of the dynamics of accelerated particle bunching in the high-current REB-excited field. Estimates are given for the accelerating field intensities in the plasma and electron acceleration rates

Time-dependent diffusive acceleration of test particles at shocks

Energy Technology Data Exchange (ETDEWEB)

Drury, L.O' C. (Dublin Inst. for Advanced Studies (Ireland))

1991-07-15

The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author).

Time-dependent diffusive acceleration of test particles at shocks

International Nuclear Information System (INIS)

Drury, L.O'C.

1991-01-01

The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author)

Precision siting of a particle accelerator

International Nuclear Information System (INIS)

Cintra, Jorge Pimentel

1996-01-01

Precise location is a specific survey job that involves a high skilled work to avoid unrecoverable results at the project installation. As a function of the different process stages, different specifications can be applied, invoking different instruments: theodolite, measurement tape, distanciometer, invar wire. This paper, based on experience obtained at the installation of particle accelerator equipment, deals with general principles of precise location: tolerance definitions, increasing accuracy techniques, schedule of locations, sensitivity analysis, quality control methods. (author)

A compact, repetitive accelerator for military and industrial applications

International Nuclear Information System (INIS)

Zutavern, F.J.; O'Malley, M.W.; Ruebush, M.H.; Rinehart, L.F.; Loubriel, G.M.; Babcock, S.R.; Denison, G.J.

1998-04-01

A compact, short pulse, repetitive accelerator has many useful military and commercial applications in biological counter proliferation, materials processing, radiography, and sterilization (medical instruments, waste, and food). The goal of this project was to develop and demonstrate a small, 700 kV accelerator, which can produce 7 kA particle beams with pulse lengths of 10--30 ns at rates up to 50 Hz. At reduced power levels, longer pulses or higher repetition rates (up to 10 kHz) could be achieved. Two switching technologies were tested: (1) spark gaps, which have been used to build low repetition rate accelerators for many years; and (2) high gain photoconductive semiconductor switches (PCSS), a new solid state switching technology. This plan was economical, because it used existing hardware for the accelerator, and the PCSS material and fabrication for one module was relatively inexpensive. It was research oriented, because it provided a test bed to examine the utility of other emerging switching technologies, such as magnetic switches. At full power, the accelerator will produce 700 kV and 7 kA with either the spark gap or PCSS pulser

Numerical simulations of intense charged particle beam propagation in a dielectric wakefield accelerator

International Nuclear Information System (INIS)

Gai, W.; Kanareykin, A.D.; Kustov, A.L.; Simpson, J.

1995-01-01

The propagation of an intense electron beam through a long dielectric tube is a critical issue for the success of the dielectric wakefield acceleration scheme. Due to the head-tail instability, a high current charged particle beam cannot propagate long distance without external focusing. In this paper we examine the beam handling and control problem in the dielectric wakefield accelerator. We show that for the designed 15.6 GHz and 20 GHz dielectric structures a 150 MeV, 40 endash 100 nC beam can be controlled and propagate up to 5 meters without significant particle losses by using external applied focusing and defocusing channel (FODO) around the dielectric tube. Particle dynamics of the accelerated beam is also studied. Our results show that for typical dielectric acceleration structures, the head-tail instabilities can be conveniently controlled in the same way as the driver beam. copyright 1995 American Institute of Physics

Kinetic modeling of particle acceleration in a solar null point reconnection region

DEFF Research Database (Denmark)

Baumann, Gisela; Haugbølle, Troels; Nordlund, Åke

2013-01-01

The primary focus of this paper is on the particle acceleration mechanism in solar coronal 3D reconnection null-point regions. Starting from a potential field extrapolation of a SOHO magnetogram taken on 2002 November 16, we first performed MHD simulations with horizontal motions observed by SOHO...... particles and 3.5 billion grid cells of size 17.5\\,km --- these simulations offer a new opportunity to study particle acceleration in solar-like settings....... applied to the photospheric boundary of the computational box. After a build-up of electric current in the fan-plane of the null-point, a sub-section of the evolved MHD data was used as initial and boundary conditions for a kinetic particle-in-cell model of the plasma. We find that sub...

Scientists confirm delay in testing new CERN particle accelerator

CERN Multimedia

2007-01-01

"Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inswitzerland on Monday confirmed a delay in tests of a massive new particle accelerator." (1 page)

Particle acceleration at corotating interaction regions in the three-dimensional heliosphere

International Nuclear Information System (INIS)

Desai, M.I.; Marsden, R.G.; Sanderson, T.R.; Balogh, A.; Forsyth, R.J.; Gosling, J.T.

1998-01-01

We have investigated the relationship between the energetic (∼1MeV) proton intensity (J) and the magnetic compression ratio (C) measured at the trailing edges of corotating interaction regions observed at Ulysses. In general, our results show that the proton intensity was well correlated with the compression ratio, provided that the seed intensity remained constant, consistent with predictions of the Fermi model. Specifically, our results indicate that particles were accelerated to above ∼1MeV in energy at or near the trailing edges of the compression regions observed in the midlatitude southern heliosphere, irrespective of whether the bounding reverse shocks were present or not. On the basis of this, we conclude that shock acceleration is probably not the only mechanism by which particles are accelerated to above ∼1MeV in energy at compression or interaction regions (CIRs). On the basis of magnetic field measurements obtained near the trailing edges of several midlatitude CIRs, we propose that particles could have been accelerated via the Fermi mechanism by being scattered back and forth across the trailing edges of the compression regions by large-amplitude Alfvacute en waves. Our results also show that the proton intensity was well correlated with the compression ratio during low solar activity periods but was essentially independent of C during periods of high solar activity. We suggest that the correlation between J and C was not observed during solar active periods because of significant variations in the seed intensity that result from sporadic contributions from transient solar events. In contrast, the correlation was observable during quiescent periods probably because contributions from transients had decreased dramatically, which allowed the CIRs to accelerate particles out of a seed population whose intensity remained relatively unperturbed. copyright 1998 American Geophysical Union

Technical training: AXEL-2008 - Introduction to Particle Accelerators

CERN Multimedia

2008-01-01

CERN Technical Training 2008: Learning for the LHC! AXEL-2008 is a course series on particle accelerators, given at CERN within the framework of the AB Operation Group Shut-down Lectures. Since 2003, this course has been organized as a joint venture between the AB Department and Technical Training and is open to a wider CERN community. The AXEL-2008 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is also open to technicians, engineers and physicists interested in this field. The course does not require any prior knowledge of accelerators. However, some basic knowledge of trigonometry, matrices and differential equations and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) from 29th January to 1st February 2008, and given in English with questions and answers als...

Technical training: AXEL-2008 - Introduction to Particle Accelerators

CERN Multimedia

2008-01-01

CERN Technical Training 2008: Learning for the LHC! AXEL-2008 is a course series on particle accelerators, given at CERN within the framework of the AB Operation Group Shut-down Lectures. Since 2003, this course is organized as a joint venture between the AB department and Technical Training, and is open to a wider CERN community. The AXEL-2008 course series is designed for technicians who are operating an accelerator, or whose work is closely linked to accelerators, but it is open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge on accelerators. However, some basic knowledge on trigonometry, matrices and differential equations, and some basic notions of magnetism would be an advantage. The course series will be composed of 10 one-hour lectures (mornings and afternoons) from the 29th of January to the 1st February 2008, and given in English with questions and answers also possible in French. The lecturer is Rende Steerenberg, engineer and sup...

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

Science.gov (United States)

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

2005-01-01

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

Particle acceleration in binaries

Directory of Open Access Journals (Sweden)

Sinitsyna V.G.

2017-01-01

Full Text Available Cygnus X-3 massive binary system is one of the powerful sources of radio and X-ray emission consisting of an accreting compact object, probably a black hole, with a Wolf-Rayet star companion. Based on the detections of ultra high energy gamma-rays by Kiel and Havera Park, Cygnus X-3 has been proposed to be one of the most powerful sources of charged cosmic ray particles in the Galaxy. The results of long-term observations of the Cyg X-3 binary at energies 800 GeV–85 TeV detected by SHALON in 1995 are presented with images, integral spectra and spectral energy distribution. The identification of source with Cygnus X-3 detected by SHALON was secured by the detection of its 4.8 hour orbital period in TeV gamma-rays. During the whole observation period of Cyg X-3 with SHALON significant flux increases were detected at energies above 0.8 TeV. These TeV flux increases are correlated with flaring activity at a lower energy range of X-ray and/or at observations of Fermi LAT as well as with radio emission from the relativistic jets of Cygnus X-3. The variability of very high-energy gamma-radiation and correlation of radiation activity in the wide energy range can provide essential information on particle mechanism production up to very high energies. Whereas, modulation of very high energy emission connected to the orbital motion of the binary system, provides an understanding of the emission processes, nature and location of particle acceleration.

Parallel beam dynamics simulation of linear accelerators

International Nuclear Information System (INIS)

Qiang, Ji; Ryne, Robert D.

2002-01-01

In this paper we describe parallel particle-in-cell methods for the large scale simulation of beam dynamics in linear accelerators. These techniques have been implemented in the IMPACT (Integrated Map and Particle Accelerator Tracking) code. IMPACT is being used to study the behavior of intense charged particle beams and as a tool for the design of next-generation linear accelerators. As examples, we present applications of the code to the study of emittance exchange in high intensity beams and to the study of beam transport in a proposed accelerator for the development of accelerator-driven waste transmutation technologies

Interdisciplinary glossary — particle accelerators and medicine

International Nuclear Information System (INIS)

Dmitrieva, V V; Dyubkov, V S; Nikitaev, V G; Ulin, S E

2016-01-01

A general concept of a new interdisciplinary glossary, which includes particle accelerator terminology used in medicine, as well as relevant medical concepts, is presented. Its structure and usage rules are described. An example, illustrating the quickly searching technique of relevant information in this Glossary, is considered. A website address, where one can get an access to the Glossary, is specified. Glossary can be refined and supplemented. (paper)

Picosecond CO2 laser for relativistic particle acceleration

International Nuclear Information System (INIS)

Pogorelsky, I.; Ben-Zvi, I.; Kimura, W.D.; Kurnit, N.A.; Kannari, F.

1994-01-01

A table-top 20-GW 50-ps CO 2 laser system is under operation at the Brookhaven Accelerator Test Facility. We compare laser performance with model predictions. Extrapolations suggest the possibility of compact terawatt CO 2 laser systems suitable as laser accelerator drivers and for other strong-field applications. Latest progress on an Inverse Cherenkov Laser Accelerator experiment is reported

Vancouver Accelerator Conference

Energy Technology Data Exchange (ETDEWEB)

Anon.

1985-06-15

Anyone who contends that particle physics is conducted in an ivory tower, not contributing to other fields of science or to humanity at large, should have attended the 1985 Particle Accelerator Conference in Vancouver. Over a thousand participants contributed 781 papers and only a fraction were actually related to accelerators for high energy physics. The majority of present developments are in the service of other fields of science, for alternative power sources, for medicine, for industrial applications, etc.

Vancouver Accelerator Conference

International Nuclear Information System (INIS)

Anon.

1985-01-01

Anyone who contends that particle physics is conducted in an ivory tower, not contributing to other fields of science or to humanity at large, should have attended the 1985 Particle Accelerator Conference in Vancouver. Over a thousand participants contributed 781 papers and only a fraction were actually related to accelerators for high energy physics. The majority of present developments are in the service of other fields of science, for alternative power sources, for medicine, for industrial applications, etc

Acceleration of superparamagnetic particles with magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Stange, R., E-mail: Robert.stange@tu-dresden.de; Lenk, F.; Bley, T.; Boschke, E.

2017-04-01

High magnetic capture efficiency in the context of Biomagnetic Separation (BMS) using superparamagnetic particles (SMPs) requires efficient mixing and high relative velocities between cellular and other targets and SMPs. For this purpose, batch processes or microfluidic systems are commonly used. Here, we analyze the characteristics of an in-house developed batch process experimental setup, the Electromagnetic Sample Mixer (ESM) described earlier. This device uses three electromagnets to increase the relative velocity between SMPs and targets. We carry out simulations of the magnetic field in the ESM and in a simpler paradigmatic setup, and thus were able to calculate the force field acting on the SMPs and to simulate their relative velocities and fluid dynamics due to SMP movement. In this way we were able to show that alternate charging of the magnets induces a double circular stream of SMPs in the ESM, resulting in high relative velocities of SMPs to the targets. Consequently, due to the conservation of momentum, the fluid experiences an acceleration induced by the SMPs. We validated our simulations by microscopic observation of the SMPs in the magnetic field, using a homemade apparatus designed to accommodate a long working-distance lens. By comparing the results of modeling this paradigmatic setup with the experimental observations, we determined that the velocities of the SMPs corresponded to the results of our simulations. - Highlights: • Investigation of a batch process setup for complex forming at Biomagnetic Separation. • Simulation of fluid flow characteristics in this Electro Magnetic Samplemixer. • Simulation of relative velocities between magnetic particles and fluid in the setup. • Simulation of fluid flow induced by the acceleration of magnet particles. • Validation of magnetic fields and flow characteristics in paradigmatic setups. • Reached relative velocity is higher than the sedimentation velocity of the particles • Alternating

Accelerator requirments for strategic defense

International Nuclear Information System (INIS)

Gullickson, R.L.

1987-01-01

The authors discuss how directed energy applications require accelerators with high brightness and large gradients to minimize size and weight for space systems. Several major directed energy applications are based upon accelerator technology. The radio-frequency linear accelerator is the basis for both space-based neutral particle beam (NPB) and free electron laser (FEL) devices. The high peak current of the induction linac has made it a leading candidate for ground based free electron laser applications

Frontier applications of electrostatic accelerators

Science.gov (United States)

Liu, Ke-Xin; Wang, Yu-Gang; Fan, Tie-Shuan; Zhang, Guo-Hui; Chen, Jia-Er

2013-10-01

Electrostatic accelerator is a powerful tool in many research fields, such as nuclear physics, radiation biology, material science, archaeology and earth sciences. Two electrostatic accelerators, one is the single stage Van de Graaff with terminal voltage of 4.5 MV and another one is the EN tandem with terminal voltage of 6 MV, were installed in 1980s and had been put into operation since the early 1990s at the Institute of Heavy Ion Physics. Many applications have been carried out since then. These two accelerators are described and summaries of the most important applications on neutron physics and technology, radiation biology and material science, as well as accelerator mass spectrometry (AMS) are presented.

Community petascale project for accelerator science and simulation: Advancing computational science for future accelerators and accelerator technologies

International Nuclear Information System (INIS)

Spentzouris, P.; Cary, J.; McInnes, L.C.; Mori, W.; Ng, C.; Ng, E.; Ryne, R.

2008-01-01

The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R and D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

AXEL-2015 - Introduction To Particle Accelerators | starting 19 January

CERN Multimedia

2014-01-01

CERN Technical Training 2015: Learning for the LHC AXEL-2015 is a lecture series on particle accelerators, given at CERN within the framework of the 2014 Technical Training Programme. As part of the BE Department’s Operations Group Shutdown Lecture series, the general accelerator physics module has been organised since 2003 as a joint venture between the BE Department and Technical Training, and is open to the general CERN community. The AXEL-2015 course is designed for technicians who are operating an accelerator or whose work is closely linked to accelerators, but it is also open to technicians, engineers, and physicists interested in this field. The course does not require any prior knowledge of accelerators. However, some basic knowledge of trigonometry, matrices and differential equations and some basic knowledge of magnetism would be an advantage. The series will consists of 10 one-hour sessions (Monday 19 January 2015 – Friday 23 January 2015, from 9 a.m. to 10.15 a.m. and ...

Dissemination and support of ARGUS for accelerator applications

International Nuclear Information System (INIS)

1992-01-01

The ARGUS code is a three-dimensional code system for simulating for interactions between charged particles, electric and magnetic fields, and complex structure. It is a system of modules that share common utilities for grid and structure input, data handling, memory management, diagnostics, and other specialized functions. The code includes the fields due to the space charge and current density of the particles to achieve a self-consistent treatment of the particle dynamics. The physic modules in ARGUS include three-dimensional field solvers for electrostatics and electromagnetics, a three-dimensional electromagnetic frequency-domain module, a full particle-in-cell (PIC) simulation module, and a steady-state PIC model. These are described in the Appendix to this report. This project has a primary mission of developing the capabilities of ARGUS in accelerator modeling of release to the accelerator design community. Five major activities are being pursued in parallel during the first year of the project. To improve the code and/or add new modules that provide capabilities needed for accelerator design. To produce a User's Guide that documents the use of the code for all users. To release the code and the User's Guide to accelerator laboratories for their own use, and to obtain feed-back from the. To build an interactive user interface for setting up ARGUS calculations. To explore the use of ARGUS on high-power workstation platforms

1999 Review of superconducting dipole and quadrupole magnets for particle accelerators