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in subjects: "Electron Guns"

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Operating experience with the ALS linac

The linac injector for the Advanced Light Source (ALS) at LBL was recently put into operation. Energy is 50 MeV, frequency 3 GHz. The electron gun delivers up to 6nC in a 3.0-ns bunch at 120 kV. A train of bunches is injected into a 1-Hz booster and accelerated to 1.5 GHz for storage ring injection. A magnetic analysis system is used for optimizing the linac. Measured beam properties from the gun and after acceleration in the linac are described. 9 refs., 3 figs.

Date: May 1, 1991

Creator: Selph, F. & Massoletti, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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X-Y spacial distribution experiments with Parmela or, what I did on my summer vacation

Experiments using the Parmela simulation program predict that the potentially uneven spacial distributions in the electron beam generated by laser emission from the photo cathode gun has no appreciable effect on the beam outcome when compared to a the more uniform thermionic gun. 23 figs., 4 tabs.

Date: August 1, 1991

Creator: Houston, J.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Proposed uv-FEL user facility at BNL

The NSLS at Brookhaven National Laboratory is proposing the construction of a UV-FEL operating in the wavelength range from visible to 750{Angstrom}. Nano-Coulomb electron pulses will be generated at a laser photo-cathode RF gun at a repetition rate of 10 KHz. The 6 ps pulses will be accelerated to 250 MeV in a superconducting linac. The FEL output will serve four stations with independent wavelength tuning, using two wigglers and two rotating mirror beam switches. Seed radiation for the FEL am… more

Date: January 1, 1991

Creator: Ben-Zvi, Ilan; Di Mauro, L. F.; Krinsky, S.; White, M. G.; Yu, L. H.; Batchelor, K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental and theoretical investigation of high gradient acceleration

This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-FG0291ER-40648. Experimental and Theoretical Investigations of High Gradient Acceleration.'' This grant supports three research tasks: Task A consists of the design and fabrication of a 17GHz of photocathode gun, Task B supports the testing of high gradient acceleration using a 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tas… more

Date: February 1, 1992

Creator: Bekefi, G.; Chen, C.; Chen, S.; Danly, B.; Temkin, R.J. & Wurtele, J.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The polarized electron gun for the SLC

A new polarized electron gun for use on the SLC at SLAC has been built and tested. It is a diode gun with a laser driven GaAs photocathode. It is designed to provide short (2ns) pulses of 10 A at 160 kV at 120 Hz. The design features of the gun and results from a testing program on a new and dedicated beam line are presented. Early results from operation on the SLC will also be shown.

Date: March 1, 1992

Creator: Schultz, D. C.; Clendenin, J.; Frisch, J.; Hoyt, E.; Klaisner, L.; Woods, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New high-brightness electron injector for free-electron lasers driven by rf linacs

A free-electron laser oscillator, driven by an rf linac, requires a train of electron bunches delivered to an undulator. The brightness requirement exceeds that available from a conventional linac with rf bunchers. The demonstrated high brightness of laser-illuminated photoemitters indicates that the conventional buncher system might be eliminated entirely, thereby avoiding the usual loarge loss in brightness that occurs in bunchers. A photoemitter with a current density of about 200 A/cm/sup 2… more

Date: January 1, 1985

Creator: Fraser, J.S.; Sheffield, R.L. & Gray, E.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Analytical methods of electrode design for a relativistic electron gun

The standard paraxial ray equation method for the design of electrodes for an electrostatically focused gun is extended to include relativistic effects and the effects of the beam's azimuthal magnetic field. Solutions for parallel and converging beams are obtained and the predicted currents are compared against those measured on the High Brightness Test Stand. 4 refs., 2 figs.

Date: May 9, 1985

Creator: Caporaso, G.J.; Cole, A.G. & Boyd, J.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Investigation of Multi-Charged Heavy Ion Production in an Electron Beam Ion Source

Measurements of multi-charged heavy ions produced in an Electron Beam Ion Source (EBIS) were carried out with a test model ion source 20 cm in length. This test model utilized an electron gun placed external to the bore of the focusing solenoid in order to achieve electrostatically focussed electron beams and isolation of the vacuum surrounding the electron gun from the vacuum in the ionization region within the solenoid bore. An ultrahigh vacuum system utilizing liquid nitrogen (77/sup 0/K) cr… more

Date: December 1, 1977

Creator: Hamm, Robert Wray

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Relativistic fluid formulation and theory of intense relativistic electron beams

A new general relativistic fluid formulation has been obtained for intense relativistic electron beams (IREB) with arbitrarily high relativistic mass factor ..gamma... This theory is valid for confined IREB equilibria such as those found inside high energy accelerators as well as in the pinched and ion-focused regimes of beam propagation in plasma channels. The new relativistic fluid formulation is based on the covariant relativistic fluid formulation of Newcomb with the parameter lambda identi… more

Date: January 1, 1984

Creator: Siambis, J.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Design of a high-brightness, high-duty factor photocathode electron gun

The proposed UV-FEL user's facility at Brookhaven National Laboratory will require a photocathode gun capable of producing short (< 6 psec) bunches of electrons in high repetition rates (5 kHz), low energy spread (< 1.5.%), a peak current of 300 A (after compression) and a total bunch charge of up to 2 nC. At the highest charge the normalized transverse emittance should be less than 7 {pi} mm-mrad. We are presently designing a gun that is expected to exceed these requirements. This gun will con… more

Date: September 1, 1991

Creator: Lehrman, I. S.; Birnbaum, I. A.; Fixler, S. Z.; Heuer, R. L.; Siddiqi, S.; Sheedy, E. (Grumman Corp., Princeton, NJ (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Investigation of electron-beam charging for inertial-confinement-fusion targets. Charged Particle Research Laboratory report No. 3-82

Techniques for charging inertial confinement fusion targets using electron beam are investigated. A brief review of the various possible charging techniques is presented, along with a discussion of the advantages and disadvantages of each. The reasons for selecting the electron beam charging and a physical picture of the charging mechanism are described. Experimental results are presented and compared with the theoretical predictions.

Date: April 1, 1982

Creator: Kim, K. & Elsayed-Ali, H.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The Los Alamos high-brightness photoinjector

For a number of years Los Alamos National Laboratory has been developing photocathode RF guns for high-brightness electron beam applications such as free-electron lasers (FELs). Previously thermionic high-voltage guns have been the source of choice for the electron accelerators used to drive FELs. The performance of such FELs is severely limited by the emittance growth produced by the subharmonic bunching process and also by the low peak current of the source. In a photoinjector, a laser driven… more

Date: January 1, 1991

Creator: O'Shea, P.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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SLAC low emittance accelerator test facility

SLAC is proposing to build a new Accelerator Test Facility (ATF) capable of producing a 50 MeV electron beam with an extremely low geometric tranverse emittance (1.5 x 10/sup -10/ rad.m) for the purpose of testing new methods of acceleration. The low emittance will be achieved by assembling a linear accelerator using one standard SLAC three-meter section and a 400 kV electron gun with a very small photocathode (40 microns in diameter). The photocathode will be illuminated from the back by short… more

Date: May 1, 1986

Creator: Loew, G. A.; Miller, R. H. & Sinclair, C. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Selective generation and extraction of low emittance electrons from plasmas: A new concept for E-beam cathodes

It is shown that hollow cathode discharges can operate in a mode characterized by a two-component electron energy distribution: bulk electrons with a thermal distribution with a temperature of a few electron volts, and a component of fast electrons with an energy of about 30 eV and a thermal spread of about 0.1 eV. Measurements of both parallel and perpendicular energy spreads confirm the existence of fast, low energy spread electrons. Selective extraction of these electrons can form the basis … more

Date: September 19, 1991

Creator: Hershcovitch, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Radio frequency photocathode guns

This report examines the causes and the effects of beam emittance growth on the performance of radio frequency photocathode guns. (LSP)

Date: April 1, 1992

Creator: Palmer, R. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Characteristics of an electron-beam rocket pellet accelerator

A proof-of-principle (POP) electron-beam pellet accelerator has been developed and used for accelerating hydrogen and deuterium pellets. An intact hydrogen pellet was accelerated to a speed of 460 m/s by an electron beam of 13.5 keV. 0.3 A, and 2 ms. The maximum speed is limited by the acceleration path length (0.4 m) and pellet integrity. Experimental data have been collected for several hundred hydrogen pellets, which were accelerated by electron beams with parameters of voltage up to 16 kV, … more

Date: January 1, 1991

Creator: Tsai, C. C.; Foster, C. A.; Milora, S. L. & Schechter, D. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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1991 Summer Research Program for High School Juniors at the University of Rochester's Laboratory for Laser Energetics

Ten students participated in the 1991 summer high school student research program at the University of Rochester's Laboratory for Laser Energetics (LLE). The participants spent 8 weeks working and learning at LLE. They spent most of their time working on individual research projects. Each student was assigned a project, upon which he/she worked under the direct supervision of one of the staff members of the laboratory. The students, their high schools, and their projects are listed in Table 1. … more

Date: September 1, 1991

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Multi-channel pulser for the SLC thermionic electron source

A new pulser developed for the SLC thermionic gun has been operational since September 1984. It consists of two planar triode amplifiers with a common output triode driving the gun cathode to produce two independent pulses of up to 9A with a 3 nsec FWHM pulse width. Three long-pulse amplifiers are also connected to the cathode to produce pulses with widths controllable between 100 nsec and 1.6 ..mu..sec. Each amplifier has independent timing and amplitude control through a fiber optic link to t… more

Date: January 1, 1985

Creator: Browne, M. J.; Clendenin, J. E.; Corredoura, P. L.; Jobe, R. K.; Koontz, R. F. & Sodja, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Beam emittance and the effects of the rf, space charge and wake fields: Application to the ATF photoelectron beam

Laser driven photoelectron guns are of interest for use in new methods of accelerations, future development of Linear Colliders and new experiments such as Free Electron laser (IFEL). Such guns are potential source of low emittance-high current and short bunch length electron beams, where the emitted electrons are accelerated quickly to a relativistic energy by a strong rf, electric field in the cavity. We present a brief overview of the beam dynamic studies, e.g. emittance for the Brookhaven N… more

Date: January 1, 1991

Creator: Parsa, Z.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development program for a 200 kW, CW, 110 GHz gyrotron. Quarterly report No. 1, June-September 1979

The objective of this program is the design and development of a millimeter-wave device to produce 200 kW of continuous-wave power at 110 GHz. The device, which will be a gyrotron oscillator, will be compatible with power delivery to an electron-cyclotron plasma. Smooth control of rf power output over a 17 dB range is required, and the device should be capable of operation into a severe time-varying rf load mismatch. Progress toward this goal is described and specifications of the gyrotron are … more

Date: January 1, 1979

Creator: Arnold, K.W.; Tancredi, J.J.; Caplan, M.; Ha, K.W.; Birnbaum, D.N. & Weiss, W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High brightness cathode experiments on the experimental test accelerator (ETA). Final report

The experiments performed on the ETA during the months of September through October of 1984 were intended to accomplish two objectives; to discover or develop a source capable of producing an electron beam whose brightness is substantially higher than that of previous sources, and to determine, if possible, the mechanisms which limit the source brightness so that further enhancements might be obtained. The results of the experiments met these objectives to a limited degree. A cathode material (… more

Date: January 1, 1984

Creator: Schlitt, L. & Proulx, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Facilities and techniques for x-ray diagnostic calibration in the 100-eV to 100-keV energy range

The Lawrence Livermore National Laboratory (LLNL) has been a pioneer in the field of x-ray diagnostic calibration for more than 20 years. We have built steady state x-ray sources capable of supplying fluorescent lines of high spectral purity in the 100-eV to 100-keV energy range, and these sources have been used in the calibration of x-ray detectors, mirrors, crystals, filters, and film. This paper discusses our calibration philosophy and techniques, and describes some of our x-ray sources. Exa… more

Date: June 1, 1986

Creator: Gaines, J. L. & Wittmayer, F. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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SLAC pulsed x-ray facility

The Stanford Linear Accelerator Center (SLAC) operates a high energy (up to 33 GeV) linear accelerator delivering pulses up to a few microseconds wide. The pulsed nature of the electron beam creates problems in the detection and measurement of radiation both from the accelerator beam and the klystrons that provide the rf power for the accelerator. Hence, a pulsed x-ray facility has been built at SLAC mainly for the purpose of testing the response of different radiation detection instruments to … more

Date: May 1, 1986

Creator: Ipe, N.E.; McCall, R.C. & Baker, E.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Large-aperture discharges in E-beam sustained CO/sub 2/ amplifiers

The very large energy fluxes required for the attainment of scientific breakeven in laser-fusion experiments can only be obtained by the construction of multiple-beam, large-aperture lasers. Accordingly, the next generation CO/sub 2/ laser currently being designed at LASL consists of six electron-beam sustained amplifier modules, each module containing 12 large-aperture (approximately 30 x 30 cm) laser discharges sustained by (and surrounding) a single, cylindrical cold-cathode electron gun. Th… more

Date: January 1, 1977

Creator: Leland, W. T.; Ganley, J. T.; Kircher, M. & York, G. W., Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department