... (Author). Descriptors : *Betatrons, Stability, Electron beams, Dispersion relations. Subject Categories : PARTICLE ACCELERATORS. ...
DTIC Science & Technology
... Abstract : Results of an extensive study of the modified betatron accelerators are reported. The topics are beam injection, equilibrium and stability. ...
... as on the thickness and atomic species ... shot accelerators that produce beams of accelerated ... stabilization us- ing controllable deceleration voltage. ...
... Descriptors : *BETATRONS, *PROTON ACCELERATORS, COMPRESSION, STABILITY, ION BEAMS, MAGNETIC INDUCTION, HIGH ENERGY ...
This invention is related to feedforward control processes and, more particularly, to adaptive feedforward processes for controlling particle accelerators. An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio...
National Technical Information Service (NTIS)
The authors investigate the stability of the driving electron or positron beam in the plasma wakefield accelerator (PWFA). Although the beam is subject to self-focusing, filamentation, and two-stream instability, they find that all of these can be stabilized by introducing thermal energy and an ...
Energy Citations Database
In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle ...
DOE Information Bridge
The theory of the stability of high intensity particle beams in circular accelerators and storage rings is developed. A simple one dimensional oscillator system is used to introduce the discussion of the stability problem and of the effect of a frequency ...
... of non-interacting single particles, launched with a distribution of initial conditions, are defocused by the finite beam emittance and focused by ...
Cascade generator stabilization by a break system interval is described. The stabilizing element is located between the low-voltage outlet of the high- intensity source and the ground. With the ion beam passing the grounded target between the last electrode on the acceleration tube and the ground, potential ...
The Advanced Test Accelerator (ATA) is a linear induction electron accelerator whose design parameters are 50 MeV, 10 kA and 70 ns pulse duration. The key physics issues affecting performance of the accelerator involve beam dynamics during transport through the accelerator structure. In this ...
The effect of finite resistance in the vacuum-tank walls on the longitudinal stability of an intense beam of particles in an accelerator is investigated theoretically. We show that even if the particle frequency is an increasing function of particle energy, the wall resistance can render the beam unstable against ...
In two-beam accelerators, the reacceleration of a modulated drive beam can enable high conversion efficiency of electron beam energy to rf energy. However, the stability issues involved with the transport of high current electron beams through rf extraction structures and ...
The Plasma Window is a stabilized plasma arc used as an interface between accelerator vacuum and pressurized targets. There is no solid material introduced into the beam and thus it is also capable of transmitting particle beams and electromagnetic radiat...
The technique and equipment for measuring energy parameters of the beam of the EhGP-10-P charge-exchange electrostatic accelerator are developed. The analysing magnet constant and its variation with energy are determined. The reproducibility and stability...
Linear accelerators driven by pulse forming networks and utilizing beam neutralization may be useful for obtaining high-current ion beams for inertial fusion applications. Such accelerators may be subject to longitudinal velocity bunching instabilities. These instabilities are studied with a computer simulation of ...
In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is ...
NASA Astrophysics Data System (ADS)
In the linear accelerators the particles are accelerated by either electrostatic fields or oscillating radio frequency (RF) fields. Accordingly the linear accelerators are divided by three large groups: electrostatic, induction and RF accelerators. Overview of different types of accelerators is ...
The theory of the stability of high intensity particle beams in circular accelerators and storage rings is developed. A simple one dimensional oscillator system is used to introduce the discussion of the stability problem and of the effect of a frequency distribution. These results are then extended to the case of ...
Proton beam stability when in collision with high current electron bunches was of foremost concern during the design stages of the HERA collider[1]. In initial commissioning the beam-beam interaction proved to be a key factor in determining the lifetime of the proton beam. It was quickly ascertained[2] that the ...
Future synchrotron radiation sources designed to produce low emittance electron beams for wigglers and undulators will present beam position control problems essentially similar to those encountered by users of existing accelerators, however tolerances wi...
A general theory of the transverse instability of coasting beams in circular accelerators produced by the interaction of the beam charge and current with its electromagnetic environment is presented. The theory allows to numerically calculate the threshold current for an arbitrary frequency versus momentum curve. The numerical solution ...
electron-positron beam facility", National Partical Accelerator Conference, 1978,Dubna, Russia, Trans.186 position stability in the accelerator. A beam Position Monitor (BPM) with the resolution better than 0B P M u p L L 0-7803-5573-3/99/$10.00@1999 IEEE. 461 Proceedings of the 1999 Particle ...
E-print Network
The results of an investigation of the characteristics of the beam accelerated up to a final energy in the 10-Bev synchrophasotron are reported. The methods of investigation are described. The following characteristics were determined: the filling of the phase stability region, the distribution in botatron oscillation ...
As a result of stripping of deuterons accelerated in the JINR proton synchrotron a beam of neutrons was formed with regulated momentum and stabilized intensity. The neutron port was formed in such a manner as to use the stripping neutrons emitted at the a...
Highlights of recent experimental and theoretical research progress on the high current beam transport of single and multiple beams by the Heavy Ion Fusion Accelerator Research (HIFAR) group at the Lawrence Berkeley Laboratory (LBL) are presented. In the single beam transport experiment (SBTE), ...
In the Compact Linear Collider (CLIC) now being studied at CERN, the rf power which accelerates the main beam is provided by decelerating a high current drive beam. The drive-beam linac has to accelerate a 4.2 A electron beam up to 2.4 GeV in almost fully loaded structures. ...
Characteristics of electron beams produced by the laser wakefield acceleration are presented. The dependence of the electron beam parameters on the laser focal spot size is investigated. The experimental result shows the generation of quasimonoenergetic electron beam although the laser spot size was several times ...
Recent demand for high-intensity beams of various particles has renewed interest in the investigation of beam current and beam quality limits in linear RF and induction accelerators and beam-transport channels. Previous theoretical work is reviewed, and new work on beam ...
To improve the beam brightness and the stability of the accelerator for nanobeam and microbeam applications, the Dynamitron accelerator was upgraded. Although the microbeam system at Tohoku University can focus the beam to several hundred square micrometers, its beam ...
The Direct Digital Synthesizers (DDS) have a proven record of high frequency stability in accelerator beam control. For the Low Energy Booster working in the frequency range of 47MHz to 60MHz, a highly stable, high resolution DDS can improve the longitudinal beam stabilities. With the DDS as ...
Study of the accumulations of high fluxes of accelerated particles is of great interest for determining the behavior of opposite beams and for establishing the conditions required for creating a stabilized relativistic beam. The builtup flux of charged particles is ultimately contained in a constant ...
ABS>The self-consistent field method is used to investigate the longitudinal stability of a system of identical bunches of finite dimensions interacting with a resonance structure. The growth rates and stability of the beam are determined for all possible modes of oscillation, A study is made of the dependence of the growth ...
Laser wakefield accelerators offer electron beams which could be useful for many applications. However, the problem of stabilizing the electron beam parameters has not been resolved yet. Here, we propose a method to minimize the electron beam pointing and report the generation of a relativistic ...
A new time-of-arrival (TOA) control system has been developed at the Argonne Tandem Linear Accelerator System (ATLAS) for very low intensity radioactive ion beams. This new system utilizes a plastic scintillator which intercepts a small fraction of the beam edge particles and measures the time-of-arrival of a bunched ...
The DARHT-II linear induction accelerator (LIA) accelerates a 2-kA electron beam to more than 17 MeV. The beam pulse has a greater than 1.5-microsecond flattop region over which the electron kinetic energy is constant to within 1%. The beam dynamics are diagnosed with 21 ...
A comprehensive account of developments in the field of recirculating electron accelerators is presented. Chapters are included in the role of recirculation in electron acceleration, the conventional microtron, linear accelerators and recirculation, race-track microtrons, representative projects with race-track microtrons, independent ...
The phase stability in the capture and acceleration scenario (CAS) is studied and compared with that of conventional linear electron accelerators (CLEAs). For the CAS case, it has been found that a slow phase slippage occurs due to the difference between the electron velocity and the phase velocity of the longitudinal ...
A number of high current accelerator designs utilize strong focusing in the form of helical quadrupole and axial guide fields. We obtain a linear dispersion relation for an electron beam propagating in a cylindrical waveguide subject to helical quadrupole...
Results of an extensive study of the modified betatron accelerators are reported. The topics are beam injection, equilibrium and stability. Three-dimensional particle simulations of injections were performed. The results show good agreement with theory. V...
One of the goals of the present Flash X-Ray (FXR) accelerator upgrade effort (1)(2) at Lawrence Livermore National Laboratory (LLNL) is to reduce the cavity transverse impedance, since it has been shown that beam stability is significantly affected by thi...
A plan for exploring the physics and technology of induction linac development is discussed which involves a series of increasingly sophisticated experiments. The first is the single-beam transport experiment, which has explored the physics of a single space-charge-dominated beam. Second is the multiple-beam experiment in which four ...
In a fixed-field alternating-gradient (FFAG) accelerator, the stability limits and the stability of the machine against field perturbations is very much affected by the choice of the betatron oscillation frequencies, nu /sub r/, and nu /sub z/. A general criterion for the stability of the ...
... Descriptors : *Linear accelerators, *Ion accelerators, *Particle accelerator components, *Electron accelerators, *Proton accelerators, Electron beams ...
Some beam-loading problems are investigated for the proposed LAMPF II synchrotron main ring and booster. Estimations for the feedback control requirements to reduce the power consumption, by accelerating protons beyond the Robinson stability limit, are pr...
We present a phenomenology of crystalline beams in storage rings. We use the smooth approximation to solve the equations of a test particle moving in the focussing potential of the storage ring, and in that of the other ions We find simple confinement, and stability conditions.
The equilibrium and stability of the neutral gas transport section of the White Horse beam accelerator is studied. It is found that the beam should be unstable from the two-stream instability and from beam-excited ion-acoustic waves, with the latter being a possible source of emittance growth ...
The block diagram and characteristics of the beam control device are given. The triggering and operational processes are analyzed. Beam frequency corrections reduced coherent phase oscillations to deg 0.05 r and stabilized the beam radial position to an order of plus or minus 1 mm. (tr-auth)
Energy deposition issues are extremely important in the Very Large Hadron Collider (VLHC) with huge energy stored in its 20 TeV (Stage-1) and 87.5 TeV (Stage-2) beams. The status of the VLHC design on these topics, and possible solutions of the problems are discussed. Protective measures are determined based on the operational and accidental beam loss ...
Advanced laser wakefield accelerators offer electron beams which could be useful for many applications. However, the problem of stabilizing the electron beam parameters has not been resolved yet. Here, we report the generation of a relativistic electron beam with a ...
The influence of amplitude value fluctuations of the collective accelerator system parameters on the stability of electron ring number in the Ne ring on the radius of equilibrium orbit is considered. It is shown that for holding ( delta Ne/Ne) value on th...
Beam stability and operational reliability of critical mechanical systems are key performance issues for synchrotron accelerators such as the Advanced Photon Source (APS). Stability is influenced by temperature fluctuations of the process water (PW) used ...
Electron accelerator sources of radiation for industrial processes must maintain constant and reproducible irradiation parameters in order to provide satisfactory dose quality assurance. The advanced control system used in AECL's IMPELATM series of accelerators ensures this by making it possible to decouple the primary accelerator ...
For an energy-efficient accelerator system to be used for a free-electron laser, the stability of an energy-recovery system utilizing a bridge coupler placed between the accelerator and the decelerator is studied numerically. Energy is recovered by recirculating the accelerated electron beam ...
The Holifield Facility 25URC tandem accelerator will begin accelerating radioactive ion beams (RIBs) for nuclear structure and astrophysics research in 1996. This paper addresses the development of the accelerator to allow optimum operation with the particular challenges associated with RIBs. New diagnostics for ...
The production of high energy (multi-GeV) proton beams by an electron ring accelerator is considered. Both the final energy and intensity of the proton beam depend on the choice of parameters for the electron ring. Possible sets of parameters, consistent with all the known requirements of ring stability, and which ...
The dynamics of the beam in structure-based wakefield accelerators leads to beam stability issues not ordinarily found in other machines. In particular, the high current drive beam in an efficient wakefield accelerator loses a large fraction of its energy in the decelerator ...
In this paper, we present a series of analytic expressions to predict the beam dynamics in a long linear accelerator. These expressions can be used to model the linac optics, calculate the magnitude of the wakefields, estimate the emittance dilution due to misaligned accelerator components, and estimate the ...
There are two major issues that are to be confronted in the design of a Fixed-Field Alternating-Gradient (FFAG) accelerator, namely: (1) the stability of motion over the large momentum range needed for the beam acceleration, and (2) the compactness of the trajectories over the same momentum range to limit the ...
Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of ...
... High current electron beam transport in ... Descriptors : *BEAM FORMING, *ELECTRON ACCELERATORS, *ELECTRON BEAMS, HIGH ENERGY ...
The suitable source for the production of intense beams for high power accelerators must obey to the request of high brightness, stability, and reliability. The 2.45 GHz off-resonance microwave discharge sources are the ideal device to generate the requested beams, as they produce multimilliampere ...
PubMed
A new approach to solving the kinetic equation for the beam distribution function, (very useful from the practical point of view), is discussed, in which the authors also obtain a complement to the Skrinsky's condition for the self-focused bunched beam. This problem belongs to the theory of nonlinear systems in which both regular and chaotic ...
A design study has recently been conducted for exploring the feasibility of a relativistic-klystron two-beam accelerator (RK-TBA) system as a rf power source for a 1 TeV linear collider. The author present, in this paper, the beam dynamics part of this study. They have achieved in their design study acceptable transverse and ...
This report discusses the follow topics on radio frequency quadrupole accelerators: RFQ characteristics; low velocity accelerators; alternating-gradient focusing; acceleration; RFQ accelerator; bunching; adiabatic capture; injectors; transverse input matching; rf structures; mechanical designs; structure ...
Beam-beam effects present one of major factors limiting the luminosity of colliders. In the linac-ring option of eRHIC design, an electron beam accelerated in a superconducting energy recovery linac collides with a proton beam circulating in the RHIC ring. There are some features of beam-beam ...
The article compares the relative stability of MCM-41 and related mesoporous materials in electron beam at an accelerating voltage of 100 300 kV. The work encountered in electron microscopy presents a comparison with similar research that has been carried out on nonporous and microporous silicates, especially [alpha]-quartz and zeolite ...
The linear induction accelerator, RADLAC II, is being upgraded to produce a 20-MeV, 40-kA annular beam. Previously, the accelerator produced a 15-MeV, 15-kA beam. Improvements in the pulsed power, injector design, and magnetic field have resulted in a faster rising, flat-topped voltage pulse. The first experiments ...
A digital fast feedback system for beam energy and position stabilization at the target of the CEBAF accelerator is capable of suppressing beam motion in the frequency band from 0 to 80 Hz and also performs narrow band suppression at the first twelve power line harmonics. The system utilizes two VME computers and ...
This paper investigates dynamic stability of an axially accelerating viscoelastic beam undergoing parametric resonance. The effects of shear deformation and rotary inertia are taken into account by the Timoshenko thick beam theory. The beam material obeys the Kelvin model in which the material ...
A model has been developed to analyze the static and dynamic behavior of superconducting accelerating cavities operated in self-excited loops in the presence of phase and amplitude feedback, ponderomotive effects, and beam loading. This is an extension of an earlier analysis of the stabilization of superconducting cavities which has ...
... Accelerators and Colliders; Beam Dynamics; Applications and New Methods of Acceleration; New Methods; Linear Accelerators and Pulsed Power ...
The high power RF system of the NIST-LANL RTM has been tested at nominal full power levels and has accelerated electron beams successfully. RF stability and calibration measurements have been made using the accelerated electron beam. These measurements have been used to calculate the effective ...
The magnetic-optics channel which shapes the extracted 70-GeV proton beam of the accelerator of the Institute of High-Energy Physics for neutrino experiments is described. The tolerances on the adjustment and the stability of the electrical power supplies for the magnetic elements of the channel, the influence of the field harmonics on ...
Section 2.5.8 of the Handbook of Accelerator Physics and Engineering on Landau damping is rewritten. An solvable example is first given to demonstrate the interplay between Landau damping and decoherence. This example is an actual one when the beam oscillatory motion is driven by a wake force. The dispersion relation is derived and its implication on ...
Cellulose is a natural raw material used in great quantity as stabilizer, tabletting agent, anti-caking agent, flavor carrier, etc. Due to its structure it has limited uses exhibiting some disadvantages in certain applications. Irradiation technique is frequently used to change the polymeric materials. The purpose of the work is to discuss the action of ...
Beam stability issues of the VLHC rings in Phase 1 and Phase 2 are reviewed. For accelerator rings of circumference 232 km and beam pipe radius of the order of 1 cm, the impedance of the vacuum chamber is dominated by the resistive wall. The most dangerous instabilities are the single-bunch transverse mode coupling ...
In order to study the spin structure of the neutron at high energy, a beam rich in polarized neutrons needs to be developed. The neutron has no charge and cannot be accelerated, so either deuterons or helions must be considered. When it comes to spin manipulation and stability of the polarization in a circular ...
A phase oscillation damping system has been deveioped and successfully tested at the Brookhaven cosmotron. Pbase differences between the induced voltage in the beam pickup plates and the rf accelerating voltage are detected and fed back to the frequency control system. The frequency of the rf accelerating voltage is thus ...
Density perturbations in a hydrogen-filled capillary discharge waveguide have been used to control the injection of electrons into a laser wakefield. This has allowed injection and acceleration in channels of lower density than previously possible, and the production of relativistic electron beams with improved stability. For ...
... Descriptors : *ELECTRON ACCELERATORS, *LINEAR ACCELERATORS, USSR, ALIGNMENT, ELECTRON BEAMS, PRECISION ...
We review the current and future accelerator technologies for generation of high brightness radiation beam.
During the past several years there has been an increasing interest in using wakefield acceleration techniques as a means for achieving TeV energies with the next generation of linear colliders. The principal design goals for a wakefield accelerator that is to be sued in this context are high accelerating gradients and large ...
Advances in and physics of the acceleration of particles using underdense plasma structures driven by lasers were the topics of presentations and discussions in Working Group 1 of the 2010 Advanced Accelerator Concepts Workshop. Such accelerators have demonstrated gradients several orders beyond conventional machines, with ...
The RADLAC program encompasses high power electron beam propagation experiments and accelerator development, both for advanced propagation experiments and to develop compact accelerator options for future charged particle beam weapons (CPBW). Propagation experiments include conditioning cell and lead pulse ...
ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and ...
The phase stability of the output power from high-power microwave tubes is a critical issue in applications such as electron acceleration and radar. The radio frequency (rf) phase stability of cyclotron autoresonance maser (CARM) amplifiers is investigated, and the phase stability of a CARM amplifier with a ...
The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 ...
... joint planning, national and international ... ETA (Experimental Test Accelerator) Beam Channel. ... BEAMS, *PARTICLE ACCELERATORS, RADIATION ...
... PRESSURE STABILIZED BEAM FINITE ELEMENT -- 6 PERFORMING ORG. ... PRESSURE STABILIZED BEAM FINITE ELEMENT INTRODUCTION ...
... (Author). Descriptors : *ION ACCELERATORS, ELECTROMAGNETS, ION BEAMS, FOCUSING, RINGS, USSR, LINEAR ACCELERATORS. ...
This report contains lecture notes on beam dynamics and acceleration concepts in particle accelerators. (LSP)
... Descriptors : *LINEAR ACCELERATORS, *MEDICAL EQUIPMENT, ELECTRON ACCELERATORS, RADIOTHERAPY, ELECTRON BEAMS ...
... joint planning, national and international ... ACCELERATORS, *PROTON ACCELERATORS, PARTICLE ACCELERATOR TECHNIQUES ...
The Ground Test Accelerator (GTA) under construction at the Los Alamos National Laboratory is part of the Neutral Particle Beam Program supported by the Strategic Defense Initiative Office. The GTA is a full-sized test facility to evaluate the feasibility of using a negative ion accelerator to produce a neutral particle ...
Beam-beam effects present one of major factors limiting the luminosity of colliders. In the linac-ring option of the eRHIC design, an electron beam accelerated in a superconducting energy recovery linac(ERL) collides with a proton beam circulating in the Rille ring. Some specific features of ...
... designed electron guns can generate electron beams with emmitance ... NEC, provide beam acceleration without increasing beam emittance, and d ...
... Title : Investigation of Ion Beam Production and Acceleration Using Linear Electron Beams and a Pulse Powered Plasma Focus. ...
Beam dynamics issues affect many different aspects of the SLC performance. This paper concentrates on the multi-particle beam dynamics in the linac and the associated limitations that are imposed on the overall SLC performance. The beam behavior in the presence of strong wakefields has been studied in order to optimize the performance ...
A simple theoretical study and numerical estimate is presented for the transverse amplitude growth of a nonrelativistic heavy ion beam in an induction linac, as envisaged for use in commercial power plants, due to the nonregenerative coherent beam breakup mode. An equivalent electrical circuit has been used to represent the ...
The E-157 plasma wakefield experiment addresses issues relevant to a meter long plasma accelerator module. In particular, a 1.4 m long plasma source has been developed for the experiment. The transverse dynamics of the beam in the plasma is studied: multiple betatron oscillations of the beam envelope, flipping of the ...
This book contains papers on the following topics: an introduction to the physics of particle accelerators; transverse motion of single particles in accelerators; fundamentals-longitudinal motion; rf system considerations for a large hadron collider; beam observation and the nature of instabilities; bunched beam ...
