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in subjects: "Lepton Beams"

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A possible design for the NLC e sup + source

The Next Linear Collider (NLC) currently under investigation at SLAC requires a positron source with a flux of about 8.6 {times} 10{sup 13} particles per second, 14.4 times more than the SLC source. Based on the SLC experience, a source for NLC is proposed that can be realized with present accelerator technology. It consists of a 7 GeV S-band electron linac, a solid moving target, a 1.8 GeV L-band positron accelerator and a pre-damping ring with a large acceptance. The pre-damping ring performs… more

Date: February 1, 1992

Creator: Braun, H. (Paul Scherrer Inst. (PSI), Villigen (Switzerland)); Clendenin, J.; Eucklund, S.; Kulikov, A. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)) & Pitthan, R. (European Organization for Nuclear Research, Geneva (Switzerland))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Cavity-coupling investigation for the PHERMEX 50 MHz rf accelerator

The PHERMEX accelerator is a three-cavity rf linac that operates at 50 MHz. Each cavity has a radius of 2.3 m and a length of 2.6 m. The accelerator produces an electron beam with a peak current of 500 A and energy of 30 MeV. The rf power is supplied by multiple 2.5-MW tetrodes feeding coaxial lines with loops in the cavity wall. To increase the fields, multiple tetrodes and coupling loops must be used in each cavity; the problems associated with multiple-loop coupling are investigated. 3 refs.… more

Date: January 1, 1985

Creator: Pogue, E.W. & Buskirk, F.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Large-area cold-cathode grid-controlled electron gun for Antares

The CO/sub 2/ laser amplifiers used in the Antares inertial confinement fusion project require large-area radial beams of high-energy electrons to ionize the laser medium before the main discharge pulse is applied. We have designed a grid-controlled, cold-cathode electron gun with a cylindrical anode having a window area of 9.3 m/sup 2/. A full diameter, 1/4 length prototype of the Antares gun has been built and tested. The design details of the Antares electron gun will be presented as well as… more

Date: January 1, 1979

Creator: Scarlett, W. R.; Andrews, K. & Jansen, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Snakes, rotators, serpents and the octahedral group

Specific configurations of horizontal and vertical bending magnets are given that, when acting on the spin polarization vector of a particle beam, generate a group of 24 operators isomorphic to the group of rotational symmetries of a cube, known as the octahedral group. Some of these configurations have the feature of converting transversely polarized beams to longitudinally polarized beams (or vice versa) at the midpoint of the configuration for, in principle, all beam energies. Since the firs… more

Date: April 1, 1986

Creator: Fieguth, T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Determination of the radius of a self-pinched beam from its energy integral

The total transverse energy (kinetic plus potential) of a self-pinched beam may be used to predict the final equilibrium radius when the beam is mismatched at injection. The dependence of potential energy on the current profile shape is characterized by a dimensionless parameter C(z), variations of which are correlated with the change of emittance.

Date: January 2, 1980

Creator: Lee, Edward P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Transverse electron resonance accelerator

Transverse (to the velocity, v, of the particles to be accelerated) electron oscillations are generated in high (e.g. solid) density plasmas by either an electromagnetic wave or by the field of charged particles traveling parallel to v. The generating field oscillates with frequency ..omega.. = ..omega../sub p/, where ..omega../sub p/ is the plasma frequency. The plasma is confined to a sequence of microstructures with typical dimensions of d approx. = 2..pi..c/..omega../sub p/, allowing the ge… more

Date: January 1, 1985

Creator: Csonka, P.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design and construction of the photocathode electron gun cavity

A 1300-MHz, two-cell rf accelerator cavity has been constructed for the high-brightness photocathode electron source program. Each cell has an rf drive. Cell one has a replacement photocathode plug on the back wall and has a shape designed for linear radial fields. Cell two has a more standard high-shunt-impedance shape. SUPERFISH values for shunt impedances are, respectively, 29.5 and 45.8 M/Omega//m. Peak surface field maximums are 58.9 and 32.1 MV/m for an electron acceleration of 0.9 and 1.… more

Date: January 1, 1988

Creator: Gray, E.R. & Fraser, J.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

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

A novel advanced accelerator is proposed. The counterstreaming electron beam accelerator relies on the same physical mechanism as that of the plasma accelerator but replaces the stationary plasma in the plasma accelerator by a magnetized relativistic electron beam, drifting antiparallel to the driving source and the driven particles, as the wave supporting medium. The plasma wave in a counterstreaming electron beam can be excited either by a density-ramped driving electron beam or by properly b… more

Date: March 1, 1987

Creator: Yan, Y.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The Brookhaven National Laboratory (BNL) Accelerator Test Facility

The design of the Brookhaven National Laboratory Accelerator Test Facility is presented including the design goals and computational results. The heart of the system is a radiofrequency electron gun utilizing a photo-excited metal cathode followed by a conventional electron linac. The Nd:YAG laser used to drive the cathode with 6 ps long pulses can be synchronized to a high peak power CO{sub 2} laser in order to study laser acceleration of electrons. Current operational status of the project wi… more

Date: January 1, 1990

Creator: Batchelor, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Digitally based pattern generator for an electron-beam welder

A digitally based deflection generator for an electron-beam welder is presented. Up to seven patterns of any shape are stored in programmable read-only memory (PROM). The pattern resolution is 39% at frequencies from 10 Hz to 1 kHz and can be x-t, y-t, or x-y formed. Frequency and pattern selections may be chosen by the welder computer or manually selected on the front panel. The ability to repeatedly synchronize two waveforms of any shape and frequency enables an unlimited variety of welds.

Date: February 19, 1981

Creator: Whitten, L. G., III

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Propagation of a Nonrelativistic Electron Beam in a Plasma in a Magnetic Field

Propagation of a nonrelativistic electron beam in a plasma in a strong magnetic field has been studied using electrostatic one-dimensional particle simulation models. Electron beams of finite pulse length and of continuous injection are followed in time to study the effects of beam-plasma interaction on the beam propagation. For the case of pulsed beam propagation, it is found that the beam distribution rapidly spreads in velocity space generating a plateaulike distribution with a high energy t… more

Date: October 1, 1986

Creator: Okuda, H.; Horton, R.; Ono, M. & Ashour-Abdalla, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Pressure and lifetime behavior of NSLS storage rings

Several contributions to the total beam lifetime in an electron storage ring are briefly discussed, including the transverse distribution of electrons in the bunch, the Touschek effect, beam-gas interactions, and various instabilities. Conditioning of the NSLS vuv and x-ray rings is described. The pressure-lifetime performance of the two rings are then presented. (LEW)

Date: January 1, 1986

Creator: Halama, H.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

An interference wiggler for precise diagnostics of electron beam energy

Relativistic electrons passing through two identical magnetic sections generate synchrotron radiation whose spectrum is strongly modulated as the photon energy varies. The modulation is caused by the interference of radiation from each section, and has been observed in the spectrum of spontaneous radiation from transverse optical klystron which utilizes two undulators. In this paper, another device based on two simple wigglers is analyzed. The device, which will be called the interference wiggl… more

Date: March 1, 1987

Creator: Kim, Kwang-Je

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Calculation of a tracking force

The original calculation (1975-76) of an electromagnetic mechanism for beam-channel tracking is presented. The system model is not realistic because only a flat profile channel which completely encloses the beam is considered. However, a clear demonstration of the existence of a tracking force is made, as a point of departure for the more recent studies which incorporate a realistic model of the beam head and conductivity profile.

Date: January 10, 1983

Creator: Lee, Edward P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Induction linear accelerator technology for SDIO applications

The research effort reported concentrated primarily on three major activities. The first was aimed at improvements in the accelerator drive system of an induction linac to meet the high repetition rate requirements of SDI applications. The second activity centered on a redesign of the accelerator cells to eliminate the beam breakup instabilities, resulting in optimized beam transport. The third activity sought to improve the source of electrons to achieve a higher quality beam to satisfy the re… more

Date: November 1, 1986

Creator: Birx, D.; Reginato, L.; Rogers, D. & Trimble, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Particle acceleration by collective effects

Successful acceleration of protons and other ions has been achieved experimentally in this decade by a number of different collective methods. The attainment of very high accelerating fields has been established although so far the acceleration distance has been confined to only a few centimeters. Efforts are in progress to understand the accelerating mechanisms in detail and, as a result, to devise ways of extending considerably the acceleration distance. A review is given of the current progr… more

Date: September 1, 1976

Creator: Keefe, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Four Exposure Holography System

A four exposure holographic interferometry system, designed for studying transient phenomena occurring on nanosecond time scales and particularly those associated with relativistic electron beams, is described. This system permits four holographic exposures of a single transient event to be made with independently adjustable interpulse spacings of from 6 to 28 nsec. The system is portable, allows for a wide range of image magnifications, features colinear scene beams to facilitate alignment and… more

Date: March 1977

Creator: Mix, L. P. & Kessler, R. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Compact electron accelerator for pumping gas lasers

A description is given of the design and application of a simple e-beam generator for the repetitive pulse pumping of gas lasers. The circuit uses a low inductance Marx and series tuned pulse forming elements.

Date: October 22, 1976

Creator: Duncan, C. V. & Bradley, L. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development of methods and procedures for high rate low energy expenditure fabrication of solar cells. Quarterly progress report No. 2, January 1--March 31, 1976

This program involves ion implantation and processing by pulsed electron beams to fabricate silicon solar cells in vacuum at high speed without the use of high-temperature operations. Individual elements of the method are being successfully developed and program objectives are being approached.

Date: April 1, 1976

Creator: Kirkpatrick, A. R. & Minnucci, J. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Lasing attempts with a microwiggler on the Los Alamos FEL

The APEX FEL normally lases near a wavelength of 3{mu}m using a permanent magnet wiggler with a 2.7-cm period and a linear accelerator of 40-MeV energy. Los Alamos National Laboratory is conducting a series of experiments with the goal of lasing at significantly shorter wavelengths with the same accelerator and the same kind of near-concentric resonator, but using a novel pulsed microwiggler of 0.5-cm period capable of generating a peak field of several tesla. We plan to lase on a fundamental w… more

Date: January 1, 1992

Creator: Warren, R. W.; O'Shea, P. G.; Bender, S. C.; Carlsten, B. E.; Early, J. W.; Feldman, D. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Thermal management of magnetic focussing horns used in the narrow and broad band neutrino beams at the AGS

Operation of the AGS Neutrino Horns and their internal and external targets takes place in an environment of high voltage, severe shock and vibration, and high radiation. To insure reliable operation, energy from Joulean heating and the proton beam interaction must be dissipated to keep component temperatures at the lowest levels practical. This has been accomplished by carefully choosing component materials and providing dedicated air and water cooling systems to transfer the 6 kW of heat effi… more

Date: January 1, 1987

Creator: Leonhardt, W.; Carroll, A.; Monaghan, R.; Pearson, C.; Pendzick, A.; Ryan, G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effects of slots/holes in disks on frequencies of TM/sub 01/ and EH/sub 11/ waves in the disk-loaded waveguide

The increase in the BBU threshold current is very important for the high and medium energy electron linacs because of a larger operating current attainable or a smaller emittance available at certain operating current. For this purpose, many means can be used, among which the improvement in the accelerating structure itself is always fundamental. SLAC's three-meter long section is unique with truly constant gradient performance. The theoretical analyses and operating experiences at SLAC have in… more

Date: March 1, 1985

Creator: Yao, C.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

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

We propose to investigate new methods of particle acceleration using a short-pulse CO{sub 2} laser as the power source and grating-like structures as accelerator cavities''. Phase I of this program is intended to demonstrate the principle of the method. We will focus the laser light to a 3 mm line on the surface of the microstructure. The structure is used to transform the electric field pattern of the incoming transversely polarized laser beam to a mode which has a component along the electron… more

Date: October 29, 1989

Creator: Chen, W.; Claus, J.; Fernow, R. C.; Fischer, J.; Gallardo, J. C.; Kirk, H. G. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Plasma beat-wave accelerator

We perform an analytic study of some quantities relevant to the plasma beat-wave accelerator (PBWA) concept. We obtain analytic expressions for the plasma frequency, longitudinal electron velocity, plasma density and longitudinal plasma electric field of a nonlinear longitudinal electron plasma oscillation with amplitude less than the wave-breaking limit and phase velocity approaching the speed of light. We also estimate the luminosity of a single-pass e/sup +/e/sup -/ linear PBWA collider assu… more

Date: June 1, 1983

Creator: Noble, R.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department