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Development of a low intensity current monitor system

Description: This report documents the development of a current transformer system used to measure pulsed ion beam currents with a wide dynamic intensity range (nA to mA, and factor of 10{sup 6}). Peak beam currents at the LAMPF accelerator typically range from 100 to nA to 40 mA with pulse widths varying from 30 to 1000 {mu}s. Signal conditioning of the peak current output provides an average current readout with a range of 1 nA to 2 mA, noise of approximately {plus minus}0.5 nA, and accuracy of {plus minu… more
Date: January 1, 1991
Creator: Gallegos, F.R.
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Partner: UNT Libraries Government Documents Department
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Optically pumped polarized ion sources

Description: Recent operating experience and development of the Optically Pumped Polarized Ion Source (OPPIS) projects at LAMPF and other laboratories is reviewed. 11 refs., 4 figs., 1 tab.
Date: January 1, 1991
Creator: van Dyck, O.B.
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Partner: UNT Libraries Government Documents Department
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MBE-4 experiments with bright Cesium+ beams

Description: Since 1985 the Heavy Ion Fusion Accelerator Research program at the Lawrence Berkeley Laboratory has been studying current amplification and emittance variations in MBE-4, a four-cesium-beam ion induction linac. This experiment models much of the accelerator physics of the electrostatically focused section of a fusion driver. Four space-charged Cs{sup +} beams, initially about one meter in length at currents of 5--10 mA, are focused by electrostatic quadrupoles and accelerated in parallel from … more
Date: August 1, 1991
Creator: Fessenden, T.J.
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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

Description: 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.
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Partner: UNT Libraries Government Documents Department
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Emittance variations in current-amplifying ion induction linacs

Description: Since 1985 the Heavy Ion Fusion Accelerator Research program at the Lawrence Berkeley Laboratory has been studying current amplification and emittance variations in MBE-4, a four-cesium-beam induction linac. This experiment models much of the accelerator physics of the electrostatically focused section of a fusion driver. Four space-charge dominated Cs{sup +} beams, initially about one meter in length at currents of 5--10 mA, are focused by electrostatic quadrupoles and accelerated in parallel … more
Date: April 1, 1991
Creator: Fessenden, T.J.
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Partner: UNT Libraries Government Documents Department
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Review of MEVVA ion source performance for accelerator injection

Description: The Mevva (metal vapor vacuum arc) ion source provides high current beams of multiply-charged metal ions suitable for use in heavy ion synchrotrons as well as for metallurgical ion implantation. Pulsed beam currents of up to several amperes can be produced at ion energies of up to several hundred keV. Operation has been demonstrate for 48 metallic ion species: Li, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, Sr, Y, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Ba, La, Ce, Pr, Nd, Sm, Gd, Dy,… more
Date: May 1, 1991
Creator: Brown, I.G.; Godechot, X. (Lawrence Berkeley Lab., CA (USA)); Spaedtke, P.; Emig, H.; Rueck, D.M. & Wolf, B.H. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany, F.R.))
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Partner: UNT Libraries Government Documents Department
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Operation of a TFTR ion source with a ground potential gas feed into the neutralizer

Description: TFTR long pulse ion sources have been operated with gas fed only into the neutralizer. Gas for the plasma generator entered through the accelerator rather than directly into the arc chamber. This modification has been proposed for tritium beam operation to locate control electronics at ground potential and to simplify tritium plumbing. Source operation with this configuration and with the nominal gas system which feeds gas into both the ion source and the center of the neutralizer are compared.… more
Date: July 1, 1991
Creator: Kamperschroer, J. H.; Dudek, L. E.; Grisham, L. R.; Newman, R. A.; O'Conner, T. E.; Stevenson, T. N. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transverse emittance studies of an induction accelerator of heavy ions

Description: Current amplification of heavy ion beams is an integral feature of the induction linac approach to heavy ion fusion. As part of the Heavy Ion Fusion Accelerator Research program at LBL we have been studying the evolution of the transverse emittance of ion beams while they are undergoing current amplification, achieved by longitudinal bunch compression and acceleration. Experiments are conducted on MBE-4, a four beam Cs{sup +} induction linac. The space-charge dominated beams of MBE-4 are focuse… more
Date: April 1, 1991
Creator: Garvey, T.; Eylon, S.; Fessenden, T.J.; Hahn, K. & Henestroza, E.
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Partner: UNT Libraries Government Documents Department
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New beam instrumentation in the AGS Booster

Description: The AGS Booster was designed to accelerate beams from 2{times}10{sup 10} polarized protons to 1.5{times}10{sup 13} protons and heavy ions through Au{sup +33}. The range of beam parameters and the high vacuum, and radiation environment presented challenges for the beam instrumentation. Some interesting beam monitors in the Booster and transport lines, will be described. Where available, results will be presented. 21 refs., 7 figs.
Date: January 1, 1991
Creator: Witkover, R.L.
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Partner: UNT Libraries Government Documents Department
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Beam instrumentation in the AGS Booster

Description: The AGS Booster was designed to accelerate low intensity (2 {times} 10{sup 10}) polarized protons, high intensity (1.5{times}10{sup 13}) protons and heavy ions through Au{sup +33}. Coping with this wide range of beams, the 3 {times} 10{sup {minus}11} Torr vacuum and the radiation environment presented challenges for the beam monitors. Some of the more interesting instrumentation design and performance during the recent Booster proton commissioning will be described.
Date: January 1, 1991
Creator: Witkover, R.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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REX, a 5-MV pulsed-power source for driving high-brightness electron beam diodes

Description: The Relativistic Electron-beam Experiment, or REX accelerator, is a pulsed-power source capable of driving a 100-ohm load at 5 MV, 50 kA, 45 ns (FWHM) with less than a 10-ns rise and 15-ns fall time. This paper describes the pulsed-power modifications, modelling, and extensive measurements on REX to allow it to drive high impedance (100s of ohms) diode loads with a shaped voltage pulse. A major component of REX is the 1.83-m-diam {times} 25.4-cm-thick Lucite insulator with embedded grading ring… more
Date: January 1, 1991
Creator: Carlson, R.L.; Kauppila, T.J. & Ridlon, R.N.
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Partner: UNT Libraries Government Documents Department
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Vacuum behavior of the x-ray lithography source

Description: Photon stimulated desorption, PSD, is the major source of the gas load in electron storage rings and therefore strongly influences both beam lifetime and beam quality. The 200 MeV compact ring at the NSLS is an ideal tool to study PSD since its energy can be varied from 60 to 200 MeV and the photoelectrons produced by synchrotron radiation can be measured in clearing electrodes installed to collect trapped ions. Using these electrodes we show: (1) photoelectrons are produced only by photons hav… more
Date: January 1, 1991
Creator: Halama, H.J. & Murphy, J.B.
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Partner: UNT Libraries Government Documents Department
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Electron-beam generation, transport, and transverse oscillation experiments using the REX injector

Description: The REX machine at LANL is being used as a prototype to generate a 4-MV, 4.5-kA, 55-ns flat-top electron beam as a source for injection into a linear induction accelerator of the 16-MeV Dual-Axis Radiographic Hydrotest facility. The pulsed-power sources drives a planar velvet cathode producing a beam that is accelerated through a foilless anode aperture and transported by an air core magnetic lens for injection into the first of 48 linear induction cells. Extensive measurements of the time-reso… more
Date: January 1, 1991
Creator: Carlson, R.L.; Allison, P.W.; Kauppila, T.J.; Moir, D.C. & Ridlon, R.N.
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Partner: UNT Libraries Government Documents Department
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Status of the uranium upgrade of ATLAS

Description: The ATLAS Positive Ion Injector (PII) is designed to replace the tandem injector for the ATLAS heavy-ion facility. When the PII project is complete, ATLAS will be able to accelerate all ions through uranium to energies above the Coulomb barrier. PII consists of an ECR ion source on a 350 KV platform and a very low-velocity superconducting linac. The linac is composed of an independently-phased array of superconducting four-gap interdigital resonators which accelerate over a velocity range of .0… more
Date: January 1, 1991
Creator: Bollinger, L. M.; Billquist, P. J.; Bogaty, J. M.; Clifft, B. E.; Markovich, P.; Munson, F. H. et al.
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Partner: UNT Libraries Government Documents Department
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Fixed Field Alternating Gradient recirculator for heavy ion fusion

Description: A heavy ion fusion driver is considered in which a beam is passed repeatedly through a LIA (linear induction accelerator) by recirculating with two spiral sector FFAG (Fixed Field Alternating Gradient) 180 degree bends. The driver consists of three such rings: a 10--100 MeV low energy ring (LER), a 100--1000 MeV medium energy ring (MER), and a 1--10 GeV high energy ring (HER). Using a scaling field of 14 kG and taking the length of the straight sections to equal the path length in the bends, th… more
Date: March 1, 1991
Creator: Paul, A.C. & Neil, V.K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Beam current monitoring in the AGS Booster and its transfer lines

Description: The new AGS Booster is designed to accelerate low intensity polarized protons and heavy ions, and high intensity protons. The wide range of beam parameters and the vacuum, thermal and radiation environment, presented challenges in the instrumentation design. This paper describes the problems and solutions for the beam current monitors in the Booster and its transport lines. Where available, results of the initial operation will be presented. 11 refs., 3 figs.
Date: January 1, 1991
Creator: Witkover, R.L.; Zitvogel, E. & Castillo, V.
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Partner: UNT Libraries Government Documents Department
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Dynamics of lattice damage accumulation for MeV ions in silicon

Description: Although the domination of electronic stopping over nuclear stopping may be regarded as an important practical advantage for high energy (MeV) ion processing, exact knowledge of the doping introduced into the active regions as well as of the process-associated defects and their thermal stability is essential for an understanding of device performance. In the present work we review that the results of our recent investigations into lattice damage accumulation in single crystal Si resulting from … more
Date: January 1, 1991
Creator: Golanski, A. (Centre National d'Etudes des Telecommunications (CNET), 38 - Meylan (France)); Grob, A.; Grob, J.J. (Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires); Holland, O.W.; Pennycook, S.J. & White, C.W. (Oak Ridge National Lab., TN (USA))
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Partner: UNT Libraries Government Documents Department
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Space charge and wake field analysis for a high brightness electron source

Description: We present a brief overview of the formalism used, and some simulation results for transverse and longitudinal motion of a bunch of particles moving through a cavity (e.g., the Brookhaven National Laboratory high brightness photocathode gun), including effects of the accelerating field, space charge forces (e.g., arising from the interaction of the cavity surface and the self field of the bunch). 3 refs., 12 figs.
Date: January 1, 1991
Creator: Parsa, Z.
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Partner: UNT Libraries Government Documents Department
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Low-emittance uniform density Cs sup + sources for heavy ion fusion accelerators studies

Description: Low-emittance (high-brightness) Cs{sup +} thermionic sources were developed for the heavy ion induction linac experiment MBE-4 at LBL. The MBE-4 linac accelerates four 10 mA beams from 200 ke V to 900 ke V while amplifying the current up to a factor of nine. Recent studies of the transverse beam dynamics suggested that characteristics of the injector geometry were contributing to the normalized transverse emissions growth. Phase-space and current density distribution measurements of the beam ex… more
Date: April 1, 1991
Creator: Eylon, S.; Henestroza, E.; Garvey, T.; Johnson, R. & Chupp, W.
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Partner: UNT Libraries Government Documents Department
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The diagnostics system for the multiple heavy ion beams induction linac experiment, MBE-4

Description: MBE-4 is a four beam current amplifying induction linac experiment conducted at LBL as a part of the Heavy Ion Fusion Accelerator Research (HIFAR) program for studying accelerator physics issues of a heavy ion driver for inertial fusion. The four ion beams (Cs{sup +}, 10 mA) are focused by electrostatic quadrupoles and accelerated fro about 200 keV to 900 keV through 24 induction gaps. Current amplification of up to nine times is achieved while the beam pulse duration is compressed from about 3… more
Date: September 1, 1991
Creator: Eylon, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The diagnostics system for the multiple heavy ion beams induction linac experiment, MBE-4

Description: MBE-4 is a four beam current amplifying induction linac experiment conducted at LBL as a part of the Heavy Ion Fusion Accelerator Research (HIFAR) program for studying accelerator physics issues of a heavy ion driver for inertial fusion. The four ion beams (Cs{sup +}, 10 mA) are focused by electrostatic quadrupoles and accelerated fro about 200 keV to 900 keV through 24 induction gaps. Current amplification of up to nine times is achieved while the beam pulse duration is compressed from about 3… more
Date: September 1, 1991
Creator: Eylon, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Beam loading in a high current accelerating gap

Description: Energy exchange between a high-current beam and a source at an accelerating gap is treated with a simple transmission line theory. There exists a matching condition for which the beam energy gain is equal to the source voltage. The total energy gain in a multigap system is expressed in terms of individual source voltages and the beam current.
Date: January 1, 1991
Creator: Rhee, M. J. & Ding, B. N.
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Partner: UNT Libraries Government Documents Department
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Upgrade of LAMPF's 750-keV, H sup + transport

Description: The results of the upgrade to the 750-keV H{sup +} transport at LAMPF are reported. The transport takes the beam from the exit of the 750-kV column to the entrance of the 201-MHz drift tube linac. Components of the transport are used to bunch the beam, to match the beam to the linac, and to adjust the peak current of the beam. The transport is a critical section of LAMPF's accelerator system; a properly tuned and stable beam significantly reduces high-energy losses in the accelerator. The trans… more
Date: January 1, 1991
Creator: Hurd, J. W.; Browman, A. A.; Jones, K. W. & Jakobson, M. J.
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Partner: UNT Libraries Government Documents Department
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Beam instrumentation in the AGS Booster

Description: The AGS Booster was designed to accelerate low intensity (2 {times} 10{sup 10}) polarized protons, high intensity (1.5{times}10{sup 13}) protons and heavy ions through Au{sup +33}. Coping with this wide range of beams, the 3 {times} 10{sup {minus}11} Torr vacuum and the radiation environment presented challenges for the beam monitors. Some of the more interesting instrumentation design and performance during the recent Booster proton commissioning will be described.
Date: December 31, 1991
Creator: Witkover, R. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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