... Accession Number : ADD441802. Title : Accelerated Weathering Light Sources Compared to Sunlight Spectra,. Corporate Author : ...

... 1) The Effects of Acceleration on Precision Frequency Sources ... FThe Effects of Acceleration on Precision Frequency Sources PE: 1ILI ...

Compared to conventional particle accelerators, plasmas can sustain accelerating fields that are thousands of times higher. To exploit this ability, massively parallel SciDAC particle simulations provide physical insight into the development of next-generation accelerators that use laser-driven plasma waves. These ...

The possibility of laser driven accelerators [1] suggests the need for new structures based on micromachining and integrated circuit technology because of the comparable scales. Thus, we are exploring fully integrated structures including sources, optics (for both light and particle) and acceleration in a common ...

... RADIATION, SOURCES, SYMPOSIA, SYNCHROTRONS, ELECTRON ACCELERATORS, LINEAR ACCELERATORS, ELECTRON OPTICS ...

The potential radiological impact of high-energy, high-intensity accelerators in the environment is discussed. It is shown that there are three sources of radiation exposure to the general public resulting from the operation of high-energy accelerators. In order of importance these are (a) the prompt radiation field, produced when the ...

... Accession Number : AD0196177. Title : PARTICLE ACCELERATORS AS NEUTRON SOURCES FOR NEUTRON RADIOGRAPHS. ...

An ideal neutron beam for BNCT is a beam of epithermal neutrons, forward directed, and free of gamma rays and thermal and fast neutrons. Three neutron beams were evaluated, and compared: (1) the operating Brookhaven Medical Research Reactor (BMRR) epither...

Compared with the number of nuclear power plants that will be decommissioned over the next few years accelerators are only a ``small'' source of radioactivity although at CERN the total amount of mostly metallic material activated in the operation of the accelerators is estimated to be of the order of 15 Mtons. ...

Vibrations induced in accelerator structures can cause particle-beam jitter and alignment difficulties. Sources of these vibrations may include pump oscillations, cooling-water turbulence, and vibrations transmitted through the floor to the accelerator structure. Drift tubes (DT) in a drift tube linac (DTL) are components likely to ...

Laser driven accelerators, in which particles are accelerated by the electric field of a plasma wave driven by an intense laser, have demonstrated accelerating electric fields of hundreds of GV/m. These fields are thousands of times those achievable in conventional radiofrequency (RF) accelerators, spurring ...

The continuing need for accelerators of increasingly sophisticated characteristics requires a great variety of rf sources to provide the energy used by these accelerators. The present status of gridded tubes will be reviewed briefly. Klystrons, which are used in most large accelerators, will be considered in some ...

The current limits of magnetic focusing systems are examined and approximate formulas for long solenoids and periodic channels with short lenses (solenoids and quadrupole doublets) are derived. The characteristics and limitations of conventional sources, pulsed ion diodes, and collective-field accelerators for the generation of intense, energetic ion beams ...

Current research efforts into structure based laser acceleration of electrons utilize beams from standard RF linacs. These beams must be coupled into very small structures with transverse dimensions comparable to the laser wavelength. To obtain decent transmission, a permanent magnet quadrupole (PMQ) triplet with a focusing gradient of 560 T/m is used to ...

We apply test-particle numerical simulations to model the acceleration of inner-source C+ by a strong interplanetary shock. The model consists of three distinct parts: (a) the distribution of inner-source pickup ions; (b) the initial acceleration of pickup ions (to produce seed particles) for a kinematically ...

The effects of acceleration on quartz and atomic frequency sources are reviewed. Guidelines are provided for the specification and testing of oscillator acceleration sensitivities. The discussion includes: steady-state acceleration effects, gravity change...

The question of whether polarized beams of 12 GeV or, preferably, higher energy can be produced at other existing or planned accelerators is explored. Sources of polarized H/sup -/ ions suitable for injection into accelerators appear to be feasible with intensities in the milliampere range (an order of magnitude better than present ...

Comparisons are made between electron and proton shielding problems. The health physicist, charged with shielding either type of accelerator, must ask himself, ''Am I faced with a thick or thin shield problem.'' For the electron accelerator, he may be able to remove the photon component with medium or high Z materials ...

We present the results of a literature search into the present state-of-the-art techniques in producing, moderating, collimating, and imaging thermal neutrons, with an emphasis on radiographic diagnosis. The portable linear accelerator source we describe compares favorably with commercially available laboratory facilities for neutron ...

The turbulence produced by lower hybrid waves, during interaction of solar wind with the cometary pick-up ions, leads to stochastic acceleration of these ions. The resulting energies of the cometary ions, calculated on the assumption that the entire turbulent electric field is used up for accelerating particles, are much larger ...

There has been some feeling that a PEP upgrade might reduce the need for a 6-GeV synchrotron source. In this note we compare the two sources from a user viewpoint. Specifications for each are laid out and in conclusion, it appears that the PEP ring, at best, will be a useful source for carrying out 6-GeV R&D ...

... applications; Synchrotron light sources and free electron lasers; Low and intermediate energy accelerators; High energy hadron accelerators and ...

In an accelerator, an annular detecting coil is placed around the outer surface of a high-voltage cable through which an electron accelerator tube is connected to a dc high-voltage source. The intensity of the electron beam is measured by detecting the electrical current flowing through the high-voltage cable by means of the ...

In many future collider and FEL designs intense, short bunches are accelerated in a linear accelerator. For example, in parts of the Linac Coherent Light Source (LCLS) a bunch with a peak current of 3.4 kA and an rms length of 30 microns will be accelerated in the SLAC linac. In such machines, in order to predict ...

The possibility of simultaneously accelerating particles with a range of charge-to-mass ratios ( approximately 20%) to the same energy is proposed and demonstrated for a superconducting linac. Uranium ions stripped in a foil with eight charge states have been accelerated through a portion of the ATLAS linac from 286 to 690 MeV, with 94% of the injected ...

The possibility of simultaneously accelerating particles with a range of charge-to-mass ratios ( ~20%) to the same energy is proposed and demonstrated for a superconducting linac. Uranium ions stripped in a foil with eight charge states have been accelerated through a portion of the ATLAS linac from 286 to 690 MeV, with 94% of the injected uranium in the ...

As the frontier of particle physics moves towards higher energies, there is a mounting pressure on the accelerator physics community to develop new accelerating concepts resulting in more compact accelerators. This requires higher accelerating gradients and, owing to the trapping criterion, higher radiation ...

This report discusses the analysis and design of rf cavities and rf power sources in accelerators. (LSP).

This report presents a preliminary evaluation of the economics of using external source neutrons (provided by a DT fusion device or by a high-energy accelerator providing a proton or deuteron particle beam) for breeding fissile fuel, and compares these co...

The coarse-mesh rebalance method, based on neutron conservation, is used in discrete ordinates neutron transport codes to accelerate convergence of the within-group scattering source. Though very powerful for this application, the method is ineffective in accelerating the iteration on the discrete-ordinates-to- ...

There is considerable interest worldwide in the research which could be done at a next generation, advanced radioactive beam facility. To generate high quality, intense beams of accelerated radionuclides via the {open_quotes}isotope separator on-line{close_quotes} (ISOL) method requires two major accelerator components: a high power (100 kW) driver device ...

... and storage rings, misc.; Particle sources and injectors; Radio frequency guns and linac injectors; Particle sources; Linear accelerators; Pulsed and ...

... Accession Number : AD0193695. Title : PORTABLE ACCELERATING TUBE WITH ION SOURCE FOR NEUTRON GENERATOR. Corporate Author : ...

Photoemission shines as a source of the bright electron beams required for free-electron lasers and particle-physics accelerators.

... Pagination or Media Count : 9. Descriptors : *ION SOURCES, USSR, TRANSLATIONS, PROTON ACCELERATORS, PATENTS, INJECTORS. ...

This dissertation tests models of relativistic electron acceleration in the earth's outer radiation belt. The models fall into two categories: external and internal. External acceleration models transport and accelerate electrons from a source region in the outer magnetosphere to the inner magnetosphere. Internal ...

The injector and source of particles for the Advanced Photon Source is a 2856-MHz, S-band, electron-positron linear accelerator (linac). It produces electrons with energies up to 650 MeV or positrons with energies up to 450 MeV. Radiation measurements were made during normal electron and positron operation, as well as during several ...

For some time now, the sources of RF transverse beam steering in the SLAC Linac have been a mystery. The previously known sources, coupler asymmetries and survey misalignment, have predicted deflections which are frequently much smaller than the observed deflections. A new source of RF steering has been discovered: the tilting of ...

A large dynamic aperture for a storage ring is of importance for long lifetimes and a high injection efficiency. Measurements of the dynamic aperture of the third generation synchrotron light source Advanced Light Source (ALS) using beam excitation with kicker magnets are presented. The experiments were done for various accelerator ...

Reduced beam energy spread, fluctuation, and emittance are important to applications of compact, high gradient laser-plasma wakefield accelerators including Thomson gamma sources and high energy colliders. Experiments and simulations will be presented on control of injection to improve beam quality compared to use of self-injection by ...

Betatron and profile oscillations in linear accelerators are discussed. Beam monitoring techniques are compared. (AIP)

Tables for acceleration terminology equivalents based on human and vehicle angular and linear motion

Monte Carlo modelling of an irradiation facility, for boron neutron capture therapy (BNCT) application, using a set of advanced type, accelerator based, 3H(d,n)4He (D-T) fusion neutron source device is presented. Some general issues concerning the design of a proper irradiation beam shaping assembly, based on very hard energy neutron ...

Oak Ridge National Laboratory Physics Division The Oak Ridge Electron Linear Accelerator Pulsed Neutron Source The ORELA is a powerful electron accelerator-based neutron source...

An electron source has been built for the ATOMKI cascade generator to offer possibilities for electron acceleration. A short description of the electron source and that of some experiences connected with the acceleration of electrons is given. (auth)

The ATLAS PII-ECR ion source is the first ECR ion source to be designed for operation on a high voltage platform. The source system is required to provide beams of heavy ions with a velocity of 0.01c for subsequent acceleration by the superconducting ATLAS Positive Ion Injector linac. The ability of the system to ...

The ATLAS PII-ECR ion source is the first ECR ion source to be designed for operation on a high voltage platform. The source system is required to provide beams of heavy ions with a velocity of 0.01c for subsequent acceleration by the superconducting ATLAS Positive Ion Injector linac. The ability of the system to ...

The basic conservation laws for mass, momentum and energy along flow tubes from the sun to the Earth, together with observational constraints coming from remote sensing observations of the corona and in-situ measurements of the wind may be used to derive scaling laws relating the asymptotic solar wind properties to the source regions on the sun. This paper reviews and ...

Results are reported for a computational study of the output beam of the high-current Moscow Meson Factory (MMF) linac H+ and H? injectors for various ion source operation modes and a variety of accelerating tube optics. Values for the emittance and phase density of the beam at the exit of the accelerating tubes are presented. The ...

The basic concept of the ''Pulse Line Ion Accelerator'' is presented, where pulse power sources create a ramped traveling wave voltage pulse on a helical pulse line. Ions can surf on this traveling wave and achieve energy gains much larger than the peak applied voltage. Tapered and untapered lines are ...

Specification, heat treatment, strength, and fatigue life of the Advanced Photon Source (APS) Storage Ring 352-MHz radio frequency (RF) accelerating cavity copper is discussed. Heat transfer studies, including finite element analysis, and configuration of water cooling is described. Requirements for and techniques of machining are considered. Braze and ...

We have investigated the effect of x-ray preheat on the development of mix. In these experiments a planar foil package consisting of two materials separated by a smooth interface was ablatively accelerated using a laser produced x-ray drive source. In the normally preheated case the drive had a component which coupled to the interface, while in the low ...

We have investigated the effect of x-ray preheat on the development of mix. In these experiments a planar foil package consisting of two materials separated by a smooth interface was ablatively accelerated using a laser produced x-ray drive source. In the normally preheated case the drive had a component which coupled to the interface, while in the low ...

In this paper we discuss the potential role of pulse power technology for future high gradient accelerators. Compared to present day pulse power sources the requirements are quite modest and, with the exception of a detailed testing of high repetition rate systems, all components have been tested over several years. We review pulse ...

Increasing the power handling capabilities of rf components is an important issue for the design of rf accelerators and rf sources. RF breakdown is a phenomena that limit the high power performance. A major concern is the damage that can occur in rf components from breakdown. To better understand this damage, we have studied rf breakdown in a rectangular ...

Vibrations induced in accelerator structures can cause particle-beam jitter and alignment difficulties. Sources of these vibrations may include pump oscillations, cooling-water turbulence, and vibrations transmitted through the floor to the accelerator structure. Drift tubes (DT) in a drift tube linac (DTL) are components likely to ...

Hybrid circuits have been widely used for space and military applications. As a result, there is a requirement for determining how these circuits tolerate nuclear radiation. The paper compares reactor generated neutrons with accelerator generated neutrons for testing neutron tolerance of hybrid circuits. The paper presents data obtained by exposing hybrid ...

Recently, analytical formulas have been derived for the Feynman- and Rossi-Alpha measurements in accelerator-driven systems. In such systems, due to the multiplicity of the sources, the Feynman- and Rossi-Alpha formulas contain additional terms as compared with the traditional cases. A numerical evaluation of these formulas for systems ...

One difficulty in radiation therapy is ensuring the correct placement of the radiation field so that the radiation is delivered to the diseased regions while healthy tissues are spared. Currently, field placement is assessed by producing a transmission radiograph (portal image) using the high-energy treatment beam. Often the quality of these images is poor. One factor which influences image ...

A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear ...

The Pierce design acceleration column has been widely used to accelerate high current beams. It operates well in the space charge limited condition, and will produce beams with a temperature comparable with that of the source. It is restricted in current density, however, by the Child-Langmuir relation. If the ion ...

The results of collective simulation of a typical TeV Energy Superconducting Linear Accelerator (TESLA) are reported. Because of accelerating gradient is low and the accelerator is long compared to other TeV colliders, betatron phase mixing must be suppressed along with the usual sources of ...

The paper presents the design of an X-band accelerating section for linearizing the longitudinal phase space in the Frascati Linac Coherent Light Source (SPARC). The nine cells structure, operating on the ? standing wave mode, is fed by a central coupler and has been designed to obtain a 42 MV/m accelerating gradient. The 2D profile ...

The paper presents the design of an X-band accelerating section for linearizing the longitudinal phase space in the Frascati Linac Coherent Light Source (SPARC). The nine cells structure, operating on the ? standing wave mode, is fed by a central coupler and has been designed to obtain a 42 MV/m accelerating gradient. The 2D profile ...

The Advanced Source Development Group at BNL is currently involved in feasibility studies to replace heavy ion beams from a tandem accelerator with a possibly much more efficient and reliable EBIS, coupled with an RFQ accelerator. Discussions with Dr. Liljeby of the M. Siegbahn Institute and with Professor M. Sedlacek of the Royal ...

The new Advanced ECR (AECR) source is being developed for the 88-Inch Cyclotron at Lawrence Berkeley Laboratory. It operates at 14.5 GHz, compared to 6.4 GHz for the present LBL ECR source. An electron gun injects electrons into the plasma chamber to increase the production of high charge state ions. The first AECR beams were injected ...

The grafting of methacrylic acid, styrene (2: 1 mole ratio) co-monomer mixture on polypropylene film and fabric, was studied to compare electron accelerators and isotopes as sources of radiation. An aluminum block that contalns i/8-in.-deep pockets covered with Mylar film for holding sample and monomer during mutual ...

The AFEL accelerator has produced beams of 1 nC with peak currents greater than 100 A and a normalized, rms emittance less than 2? mm mrad. The 1300 MHz standing-wave accelerator uses on-axis coupling cells. The electron source is a photoinjector with a CsK2Sb photocathode. The photoinjector is an integral part of a single 11-cell ...

The AFEL accelerator has produced beams of greater than 2 {times} 10{sup 12} A/m{sup 2} at 1 nC (brightness = 2*I/{var_epsilon}{sup 2}, with I greater than 100 A and {var_epsilon} of than 2 {pi} mm-mrad normalized ms emittance). The 1300 MHz standing-wave accelerator uses on-axis coupling cells. The electron source is a photoinjector ...

The AFEL accelerator has produced beams of greater than 2 x 10(exp 12) A/m(exp 2) at 1 nC (brightness = 2*I/(var epsilon)(exp 2), with I greater than 100 A and (var epsilon) of than 2(pi) mm-mrad normalized ms emittance). The 1300 MHz standing-wave accelerator uses on-axis coupling cells. The electron source is a photoinjector with a ...

Laser driven sources of high energy ions commonly use thin solid foils. However, recently experiments have shown that a gaseous target can produce proton beams with characteristics comparable to those obtained with solid targets. In underdense laser proton acceleration, volume effects dominate the acceleration, ...

This report describes a turn-key system that was developed and implemented to collect the vehicle source height database for incorporation into the new Traffic Noise Model; `TNM.` A total of 2500 individual vehicle pass-byes were measured with this system at 16 different sites around Florida and this data is presented in the form of averaged curves for each vehicle type. The ...

... Descriptors : , (*IRRADIATED FOOD, PROCESSING), (*FOOD, PRESERVATION), (*ELECTRON ACCELERATORS, IRRADIATED FOOD ...

The design of the Linac Coherent Light Source (LCLS) requires two-stage bunch compression for stability against timing and charge jitters. Coherent synchrotron radiation (CSR) induced in these bunch compressors can drive a microbunching instability that may degrade the beam brightness. In this paper, we study effects of the longitudinal wakefield in the ...

A buncher is an RF accelerator followed by a drift space. Its purpose is to bunch the dc ion source beam into suitable bunches for acceleration in a linac. The voltage in a simple buncher is a sine wave at the linac frequency. A more elaborate wave form can result in increased capture of ion source beam. The ...

A sputtered ion source was developed for use with the commercial Lintott ion accelerator. This source is readily interchanged with the existing commercial sources, and it requires no modifications to the Lintott accelerator. Sample currents in excess of 1...

This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free ...

In an effort to ensure that the stability goals of the NSLS II will be met once the accelerator structure is set on the selected BNL site a comprehensive evaluation of the ground vibration observed at existing light source facilities has been undertaken. The study has relied on measurement data collected and reported by the operating facilities as well as ...

The absolute dose rate around beta sources for intravascular brachytherapy was measured with thin thermoluminescent (TL) dosimeters and radiochromic film. The calibration of these dosimeters was performed at the dose maximum in a 6 MeV electron beam of a linear accelerator. Compared to the values given by the manufacturers, higher dose ...

Current high-intensity laser sources offer a multitude of research, experiment and application possibilities, ranging from e.g. ionisation studies of atomic and molecular systems to particle acceleration for medical purposes. Planned upgrades of existing laser sources will further increase the deliverable intensities and make certain ...

In this paper, the Boltzmann equation, including ionization sources, is numerically solved by weather differencing in two spacial dimensions. The algorithm is stable and allows object boundary conditions to be installed in a natural manner. The experimental response of a cylindrical cavity to electron injection sources at pressures of 0.2 and 300 mtorr is ...

It is a known fact that blind algorithms have convergence times of an order of magnitude longer than their nonblind counterparts. However, as shown in this letter, the knowledge of a subset of signals can greatly accelerate the convergence of blind source separation. The convergence behavior of the proposed algorithm is compared with ...

It is well known that exposure to an accelerator environment can cause ``conditioning'' of the vacuum chamber surfaces. In order to understand the manner in which the surface structure might influence the production of gases and electrons in the accelerator, such surfaces should be studied both before and after exposure to accelerator ...

The problem of particle acceleration in relativistic shocks and shear flows is reviewed. We compare different acceleration mechanisms and show that the converter mechanism, suggested recently, is the least sensitive to the geometry of the magnetic field in accelerators and can routinely operate up to cosmic-ray ...

Particle acceleration based on high intensity laser systems (a process known as laser-plasma acceleration) has achieved high quality particle beams that compare favourably with conventional acceleration techniques in terms of emittance, brightness and pulse duration. A long-term difficulty associated with ...

The conditions of known experiments on the trigger acceleration of the radiative decay of isomeric nuclear states are compared. It is shown that in the case of quasi-monochromatic inducing sources, the use of Moessbauer targets can increase the efficiency of the process by a few orders of magnitude. It is pointed out that the ...

The conditions of known experiments on the trigger acceleration of the radiative decay of isomeric nuclear states are compared. It is shown that in the case of quasi-monochromatic inducing sources, the use of M�ssbauer targets can increase the efficiency of the process by a few orders of magnitude. It is pointed out that the ...

A comparison is made between the production of high intensity beams of helium-like uranium ions, U/sup 90 +/, by conventional and exotic ion sources, and by the foil stripping of highly accelerated ions output from the Bevalac. The parameter requirements are specified and compared to the parameters achievable by present day ion ...

This paper describes a systematic investigation of the understanding of the concept of acceleration among students enrolled in a variety of introductory physics courses at the University of Washington. The criterion for assessing understanding of a kinematical concept is the ability to apply it successfully in interpreting simple motions of real objects. The main thrust of ...

Accelerator-based neutron sources are an attractive alternative to nuclear reactors for providing epithermal neutron beams for Boron Neutron Capture Therapy. Based on clinical requirements and neutronics modeling the use of proton and deuteron induced reactions in {sup 7}Li and {sup 9}Be targets has been compared. Excellent epithermal ...

The C-metric is one of few known exact solutions of Einstein's field equations which describes the gravitational field of moving sources. For a vanishing or positive cosmological constant, the C-metric represents two accelerated black holes in asymptotically flat or de Sitter spacetime. For a negative cosmological constant the structure of the ...

In this paper the virtual source technique is used to compute scattering of a plane wave from a periodic ocean surface. The virtual source technique is a method of imposing boundary conditions using virtual sources, with initially unknown complex amplitudes. These amplitudes are then determined by applying the boundary conditions. The ...

Based on two conceptual design studies performed by the LANL Accelerator Technology Division, the possibilities in terms of accelerator systems for replacing ORELA with a more intense Maxwellian-type continuous-energy neutron source are summarized and discussed. The neutron intensities from ORELA are compared with ...

The authors present a new method for fast transport synthetic acceleration (TSA) of source iterations for S{sub N} problems, using a pure absorber problem stretched to have a mean free path comparable to a diffusion length. The resulting scheme is at first glance unstable, with a large negative eigenvalue at high spatial frequencies, ...

Four experiments are reported. Constant arc voltage operation was compared with constant arc current operation over a similar range of plasma density. The higher arc voltage required in the constant arc current operation produced more H/sup -/, but it was at the expense of an even larger increase in the accelerated electron current. A comparison of ...

accelerator science, and a source of many innovative concepts, within the Accelerator and Fusion Research Division. We have core expertise in accelerator physics and theory,...

accelerator science, and a source of many innovative concepts, within the Accelerator and Fusion Research Division. We have core expertise in accelerator physics and theory,...

Using the dielectric wall accelerator technology, they are developing a compact induction accelerator system primarily intended for pulsed radiography. Unlike the typical induction accelerator cell that is long compared with its accelerating gap width, th...

A laser source of neutral atoms for loading the electron rings by ions of elements chosen for acceleration in a collective accelerator has been developed and successfully tested in bench-scale experiments. The source permits to obtain fluxes of atoms of a...

Development of a 4 mA, 2.5 MeV Tandem Cascade Accelerator (TCA) for the production of neutrons via the {sup 7}Li(p,n){sup 7}Be nuclear reaction is currently nearing completion at SRL. The TCA is a tandem electrostatic accelerator which uses a high current negative ion source in conjunction with a high current solid state cascade ...

Development of a 4 mA, 2.5 MeV Tandem Cascade Accelerator (TCA) for the production of neutrons via the [sup 7]Li(p,n)[sup 7]Be nuclear reaction is currently nearing completion at SRL. The TCA is a tandem electrostatic accelerator which uses a high current negative ion source in conjunction with a high current solid state cascade ...

The operation and critical parameters of railguns are described. The potential and actual performance with other types of macroparticle accelerators is compared. Their research and industrial applications are discussed. Railgun accelerators have the poten...

We present a novel radiation hydrodynamics code, START, which is a smoothed particle hydrodynamics (SPH) scheme coupled with accelerated radiative transfer. The basic idea for the acceleration of radiative transfer is parallel to the tree algorithm that is hitherto used to speed up the gravitational force calculation in an N-body system. It is demonstrated ...

Hadron therapy, which is taken here to exclude neutrons but include ions, has its roots in a paper by Robert R. Wilson in [Radiology 47, 487 (1946)]. His paper spoke mainly of protons and the advantages of their Bragg peak behavior, but it also had the foresight to mention carbon ions. Pioneering work with different ion species was started at LBL in 1975 and continued for about 15 years. Today, ...

Diffuse optical tomographic image reconstruction uses advanced numerical models that are computationally costly to be implemented in the real time. The graphics processing units (GPUs) offer desktop massive parallelization that can accelerate these computations. An open-source GPU-accelerated linear algebra library package is used to ...

Diffuse optical tomographic image reconstruction uses advanced numerical models that are computationally costly to be implemented in the real time. The graphics processing units (GPUs) offer desktop massive parallelization that can accelerate these computations. An open-source GPU-accelerated linear algebra library package is used to ...

Basic types of accelerators for use as radiation sources are described and applications discussed. (C.J.G.)

Both travelers were members of a nine-person US delegation that participated in an international workshop on accelerator-based 14 MeV neutron sources for fusion materials research hosted by the University of Tokyo. Presentations made at the workshop reviewed the technology developed by the FMIT Project, advances in accelerator ...

As introduction a short overview of the history of brachytherapy (BT) is given, with a focus on the evolution in the photon sources that have been used over the years. A major step in this evolution was the introduction of the automatic afterloading devices, which could be compared to the introduction of linear accelerators in external ...

Radiation damage in target, container, and window materials for spallation neutron sources is am important factor in the design of target stations for accelerator-driver transmutation technologies. Calculations are described that use the LAHET and SPECTER codes to obtain displacement and helium production rates in tungsten, 316 stainless steel, and Inconel ...

Negative ion sources and the mechanisms for negative ion production are reviewed. Several classes of sources with surface origin of negative ions are examined in detail: surface-plasma sources where ion production occurs on the electrode in contact with the plasma, and pure surface'' sources ...

A functional description of multicusp H- sources is given, focusing on the fundamental elements of this source type: the discharge chamber, the extraction plasma region, and electron dumping. Design choices for these elements will be presented and compared. The options of rf and filament heating of the discharge chamber will be ...

Sandia National Laboratories (SNL) designs, tests and operates a variety of accelerators that generate large amounts of high energy Bremsstrahlung radiation over an extended time. Typically, groups of similar accelerators are housed in a large building that is inaccessible to the general public. To facilitate independent operation of each ...

Several accelerator designs are discussed in search for a greater than 1 TeV electron accelerator. The types considered are linear accelerators, the inverse Cerenkov accelerators, the wiggler (inverse free electron laser), plasma accelerators, and the grating accelerator. A ...

We compare different acceleration mechanisms in application to relativistic jets and show that the converter mechanism, suggested recently, is the least sensitive to the geometry of the magnetic field in accelerators, and can routinely operate up to cosmic-ray energies close to the fundamental limit. The converter mechanism utilizes ...

A single science textbook often provides the syllabus for courses at upper secondary and tertiary levels, and may be used as a principal source of information or explanation. The research reported in this article challenges such practices. The ways in which the concept, acceleration, is treated in physics textbooks is compared with ...

Many high energy solar energetic particles (SEPs), potentially threatening astronauts and instruments on space missions, are considered to be accelerated by CME-driven shocks in interplanetary space. So that it is important to know the mechanisms of space energetic particles transport with acceleration of CME-driven shocks. But they still remain a puzzle ...

Heavy elements detected in the atmospheres of hot white dwarfs are commonly explained in terms of a diffusion model involving an equilibrium between radiative forces and gravity. In spite of the declining relative importance of radiative accelerations at lower effective temperatures, an increasing number of cooler DA white dwarfs are also found to host significant abundances ...

Fermilab is currently constructing the 'SRF Test Accelerator at the New Muon Lab' (NML). NML consists of a photo-emitted RF electron gun, followed by a bunch compressor, low energy test beamlines, SCRF accelerating structures, and high energy test beamlines. The initial primary purpose of NML will be to test superconducting RF ...

A full 3D electromagnetic finite element analysis and particle tracking study is undertaken of the ISIS Penning surface plasma H- ion source. The extraction electrode, 90� analysing magnet, post-extraction acceleration gap and 700 mm of drift space have been modelled in CST Particle Studio 2008 to study the beam acceleration and ...

This paper reviews the requirements and current status of cathodes for accelerator applications, and proposes a research and development plan for advancing cathode technology. Accelerator cathodes need to have long operational lifetimes and produce electron beams with a very low emittance. The two principal emission processes to be considered are ...

The major radiological environmental impact of the Lawrence Berkeley Laboratory is due to the operation of four particle accelerators in the pursuit of fundamental research in various disciplines including biology, chemistry, medicine and physics. Potential sources of population exposure at the Laboratory are discussed. The major ...

In this work, the performance of an accelerator-based neutron source design has been compared with that of a modern fluoride-filtered reactor-based epithermal beam having near-optimal quality for treatment of deep seated tumors in relation to its applicability for BNCT. The accelerator is a ...

The toroidal field coils in Tore Supra are supra-conducting, and their number is restricted to 18. As a result, the ripple is fairly large, about 7% at the plasma boundary. Tore Supra has consequently been equipped with dedicated ripple loss diagnostics, which has allowed ripple loss studies. This paper reports on the measurements made with these diagnostics and provides an analysis of the ...

A prototype rf power source based on the Relativistic Klystron Two- Beam Accelerator (RK-TBA) concept is being constructed at LBNL to study physics, engineering, and costing issues. The prototype, called RTA, is described and compared to a full scale design appropriate for driving the Next Linear Collider. Specific details of the ...

During the last year, we have begun detailed development of a railgun launcher and power source. We are developing a launcher with a gas injector. The injector accelerates the projectile to more than 1 km/s reducing the dwell time of the plasma arc and the erosion of the rails. The injected projectile, with a fuse, also serves as the main switch in the ...

The major attractions of the pulsed drift-tubes are that they are non-resonant structures and that they appear suitable for accelerating a very high current bunch at low energies. The mechanical tolerances of the non-resonant structure are very loose and the cost per meter should be low; the cost of the transport system is expected to be the major cost. The pulse power ...

An over-dense microwave driven ion source capable ofproducing deuterium (or hydrogen) beams at 100-200 mA/cm2 and with atomicfraction>90 percent was designed and tested with an electrostaticlow energy beam transport section (LEBT). This ion source wasincorporatedinto the design of an Accelerator Driven Neutron ...

The authors begins by introducing both the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wakefield Accelerator (PWFA). After these two methods of producing relativistic electron plasma waves have been introduced, he begins his study of certain key accelerator issues relevant to plasma-based accelerators. ...

The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory to build a nuclear astrophysics accelerator facility 1.4 km below ground. DIANA is part of the US proposal DUSEL (Deep Underground ...

A flexible multiple source model capable of fast reconstruction of clinical electron beams is presented in this paper. A source model considers multiple virtual sources emulating the effect of the accelerator head components. A reference configuration (10MeV and 10�10cm2 field size) for a Siemens KD2 linear ...

Accelerator Driven Systems (ADS) present one of the most viable solutions for transmutation and effective utilization of nuclear fuel. Spent fuel from reactors will be partitioned to separate plutonium and other minor actinides to be transmuted in the ADS. Without the ADS, minor actinides must be stored at a geologic repository for long periods of time. One problem with ADS is ...

Typical high-energy negative ion electrostatic accelerators such as the ones designed for fusion applications produce a significant amount of secondary particles. These particles may originate from coextracted electrons, which flow from the ion source, impacting the accelerator grids or as by-products of collisions between ...

facility is composed of ion sources (PIG and ECR types), RFQ linear accelerator, Alvarez linear accelerator sources (now the 3rd ion source is added) , the recent development of time sharing mode in the acceleratorVol. 31 (2000) ACTA PHYSICA POLONICA B No 1 HEAVY ION ...

Operational problems in the production and acceleration of /sup 14/C beams for nuclear structure research in Los Alamos National Laboratory's Van de Graaff accelerators are discussed. Methods for the control of contamination in ion sources, accelerators and personnel are described. Sputter ...

In the early seventies, significant discoveries for H(-) ion sources were made at Novosibirsk. These and many improvements which followed have led to useful accelerator sources. With these sources charge-exchange injection into circular accelerators has b...

Radio-frequency (RF) driven ion sources are being developed in Lawrence Berkeley National Laboratory (LBNL) for sealed-accelerator-tube neutron generator application. By using a 5-cm-diameter RF-driven multicusp source H{sup +} yields over 95% have been achieved. These experimental findings will enable one to develop compact neutron ...

Radio-frequency (RF) driven ion sources are being developed in Lawrence Berkeley National Laboratory (LBNL) for sealed-accelerator-tube neutron generator application. By using a 5-cm-diameter RF-driven multicusp source H{sup +} yields over 95% have been achieved. These experimental findings will enable one to develop compact neutron ...

The ultrafast, high brightness x-ray free electron laser (XFEL) sources of the future have the potential to revolutionize the study of time dependent phenomena in the natural sciences. These linear accelerator (linac) sources will generate femtosecond (fs) x-ray pulses with peak flux comparable to conventional ...

Using high current, cw linear accelerator technology, a spallation neutron source can achieve much higher average intensities than existing or proposed pulsed spallation sources. With about 100 mA of 300 MeV protons or deuterons, the accelerator based neutron research facility (ABNR) would initially achieve the ...

Reports of operations are presented for twenty-seven facilities, along with reports on accelerators in progress, ion sources, insulating gases, charging systems, stripping foils, accelerating tubes, and upgraded accelerator systems. (GHT)

Some aspects of physics that contributed to design and operation of the ETA 10 kAmp electron accelerator are discussed. These include: the electron source, the emittance growth in the injector, beam transport through the accelerator, and the influence of the beam breakup accelerator instability.

An automatic frequency control system is described for maintaining the drive frequency applied to a linear accelerator to produce maximum particle output from the accelerator. The particle output amplitude is measured and the frequency of the radio frequency source powering the linear accelerator is adjusted to ...