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Plasma neutralizer for H/sup -/ beams

Description: Neutralization of H/sup -/ beams by a hydrogen plasma is discussed. Optimum target thickness and maximum neutralization efficiency as a function of the fraction of the hydrogen target gas ionized is calculated for different H/sup -/ beam energies. Also, the variation of neutralization efficiency with respect to target thickness for different H/sup -/ beam energies is computed. The dispersion of the neutralized beam by a magnetic field for different energies and different values of B . z is foun… more
Date: January 1, 1977
Creator: Grossman, M.W.
Partner: UNT Libraries Government Documents Department
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Methods for independent plasma production and beam injection for H/sup +/. -->. H/sup -/ surface conversion

Description: Based on the Oak Ridge National Laboratory (ORNL) source development program, ways to create a uniform and dense plasma are briefly reviewed. The positive ions so created will be accelerated towards a surface convertor for producing negative ions. The convertor will be used for reducing the electrons in the extraction region. The significant results and features of this study are presented.
Date: January 1, 1977
Creator: Tsai, C C; Stirling, W L & Davis, R C
Partner: UNT Libraries Government Documents Department
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H/sup -/ source development at ANL

Description: The H/sup -/ source development program at ANL has produced the first operational source for direct H/sup -/ injection into a proton synchrotron and is now directed toward the development of a 30 Hz H/sup -/ source for booster injection into a synchroton. On October 1, 1976, direct injection of 50 MeV H/sup -/ ions into the ANL Zero Gradient Synchrotron (ZGS) and stripping of the H/sup -/ to obtain protons for acceleration to full energy became the normal mode of operation. With >6 mA of 50 MeV… more
Date: January 1, 1977
Creator: Fasolo, J. A.
Partner: UNT Libraries Government Documents Department
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Elastic proton /sup 4/He scattering near 1 GeV. [Multiple diffraction theory]

Description: A multiple diffraction theory approach to p-/sup 4/He scattering is described in which all relevant corrections to Glauber theory are incorported and in which the NN amplitudes are based as far as possible on experiment. Results are compared with five sets of p-/sup 4/He data. (SDF)
Date: August 1, 1977
Creator: Wallace, S. J.
Partner: UNT Libraries Government Documents Department
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Experiments with a Dudnikov-type H source

Description: Operating characteristics of the ion source described were previously reported. It uses a Penning discharge to produce H ions by the surface-plasma principles and was constructed according to the design details presented by Dudnikov. Arc power must be held relatively constant at about 50 watts to maintain stable operation, and this occurs for an indicated cathode temperature of 500/sup 0/C. Within this limitation the source may be operated continuously at 2 mA or pulsed at over 100 mA, as measu… more
Date: January 1, 1977
Creator: Allison, P. W.
Partner: UNT Libraries Government Documents Department
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Negative hydrogen ion sources for neutral beam injectors

Description: Negative ion sources offer an attractive alternative in the design of high energy neutral beam injectors. The requirements call for a single source unit capable of yielding H/sup -/ or D/sup -/ beam currents of up to 10 A, operating with pulses of 1 s duration or longer, with gas and power efficiencies comparable to or better than achievable with double electron capture systems. H/sup -/ beam currents of up to 1 A have already been achieved in pulses of 10 ms; gas and power efficiencies were, h… more
Date: January 1, 1977
Creator: Prelec, K.
Partner: UNT Libraries Government Documents Department
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LAMPF polarized ion facility: status report

Description: The current status of the LAMPF Lamb-shift polarized ion facility is described. The 750 kV Cockcroft-Walton injector is now installed and work is proceeding on the ion source system. Engineering details are described along with an estimated operation date. Improvements in two polarized ion sources now operating at the Los Alamos Scientific Laboratory are being incorporated into this source and include recent modifications to the argon charge-changing region. The status of rapid spin-reversal te… more
Date: January 1, 1977
Creator: Chamberlin, Edwin P.; Stevens, Ralph R., Jr. & McKibben, Joseph L.
Partner: UNT Libraries Government Documents Department
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Neutralization of H/sup -/ beams with gas jets

Description: A test facility was constructed to create a compact curtain-shaped gas jet as a first-generation operational neutralizer for the 150 keV H/sup -/ beam. Different gases and vapors were considered, their optimum target thicknesses and neutralization efficiencies with respect to beam energies were explored. Two techniques of gas jet formation were compared. Multiparallel-channel effusive jets of CO/sub 2/ and H/sub 2/ were selected as test candidates.
Date: January 1, 1977
Creator: Lam, C. K.
Partner: UNT Libraries Government Documents Department
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Direct extraction H/sup -/ ion source

Description: A direct extraction H/sup -/ ion source of the Penning design described by Dudnikov was built and tested. To date a beam of 108 mA was extracted from a 10 x 0.5 mm/sup 2/ slit and transported through a 90/sup 0/ bending magnet into a Faraday cup at a duty factor of approximately 7 Hz x 700 ..mu..s (0.5 percent). The duty factor limitation is imposed by operating temperature requirements so that at reduced arc current a dc beam of 4 mA was reached.
Date: January 1, 1977
Creator: Allison, P. W.
Partner: UNT Libraries Government Documents Department
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Acceleration of one ampere negative ion beams to energies up to 120 keV

Description: One of the objectives of the BNL Neutral Beam Development Group is to accelerate negative hydrogen ion beams to energies of several hundreds of kilovolts. In a first attempt, negative ions, produced from surface plasma sources, are extracted at around 15 keV and accelerated across a single gap to energies of 120 keV. Beam currents in excess of one ampere have been accelerated.
Date: January 1, 1977
Creator: Lam, C. & Sluyters, T.
Partner: UNT Libraries Government Documents Department
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ORNL negative ion program

Description: The ORNL Negative Ion Program is interested in developing small-scale or bench type experiments which are inexpensive and are designed to test principles involved in negative ion plasma generator development. The following four ideas are being considered: (1) H/sup -/ production from H/sup +/ ions in a modified duoPIGatron; (2) double charge exchange production of H/sup -/ ions utilizing the double sheath of a duoPIGatron; (3) surface generation of negative ions from thermally dissociated hydro… more
Date: January 1, 1977
Creator: Stirling, W. L.
Partner: UNT Libraries Government Documents Department
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Injection methods in the Fermilab booster

Description: At present there are two working injection methods; single-turn using a ferrite kicker magnet and multiturn using a pulsed set of 4 dipoles in one straight section. The operating characteristics of these methods are described. The expected implementation of H/sup -/ injection will involve the incorporation of devices for all three methods in one 6-m long straight section. The H/sup -/ scheme is described and the expected operating characteristics compared to the present methods.
Date: January 1, 1977
Creator: Cosgrove, D. F.; Gray, E.; Hojvat, C.; Johnson, R. P. & Owen, C.
Partner: UNT Libraries Government Documents Department
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Negative hydrogen ion injection into the Zero Gradient Synchrotron

Description: In October 1976 the Zero Gradient Synchrotron (ZGS) became the first high energy proton synchrotron to use charge exchange injection in routine operations. Conversion to H/sup -/ injection has been very successful, yielding record high beam intensities within the first month of use and normal (>90 percent) operating efficiencies within the second month. A brief discussion is given of the history of H/sup -/ at the ZGS, the hardware uniquely associated with charge exchange injection, and the ope… more
Date: January 1, 1977
Creator: Potts, C. W.
Partner: UNT Libraries Government Documents Department
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Report of Working Group on Accelerator Problems

Description: There are many experimental elementary particle objectives which are uniquely achievable with polarized proton beams. These objectives require both higher beam energies and intensities than are presently available. The polarized ion source working group concluded that it looks quite practical to produce polarized H sources with output currents of several mA. The significance of this is best demonstrated by the fact that the ZGS operates at its space charge limit using a 6 mA H/sup -/ impolarize… more
Date: October 18, 1977
Creator: Cho, Y.; Montague, B. W.; Kubischta, W.; Turrin, A.; Courant, E. D. & Ratner, L.
Partner: UNT Libraries Government Documents Department
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Fundamental atomic collisional processes in negative ion sources for H/sup -/

Description: The basic collision processes which create or destroy H/sup -/ in gas-phase collisions like those which occur in ion sources are discussed. Cross sections are presented which show that, for known processes, destruction is generally more likely than production. One possible production mechanism (on which there is no data) is suggested, and isotope effects between hydrogen and deuterium are discussed.
Date: January 1, 1977
Creator: Crandall, D. H. & Barnett, C. F.
Partner: UNT Libraries Government Documents Department
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H/sup -/ ion source diagnostics

Description: Electrostatic probe measurements, H/sub ..cap alpha../ line broadening, and gas pressure and gas flow measurements are discussed with regard to the Brookhaven National Laboratory H/sup -/ ion source. Probe measurements imply the plasma density and electron temperature for certain source conditions. Line broadening experiments indicate an atom temperature of several tenths of an eV. The importance of fine structure splitting in analyzing the line profiles is discussed and the H/sub ..cap alpha..… more
Date: January 1, 1977
Creator: Grossman, M.W.
Partner: UNT Libraries Government Documents Department
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Development of H/sup -/ sources at Brookhaven National Laboratory

Description: Negative hydrogen ion sources have been developed at Brookhaven National Laboratory for several years, with the initial goal to design a source for accelerator applications and later on to design a large unit for applications in neutral beam injectors of magnetic fusion devices. Three types of sources were investigated, a hollow discharge duoplasmatron yielding H/sup -/currents up to 60 mA, a Penning source yielding H/sup -/ currents up to 440 mA, and a magnetron source yielding H/sup -/ curren… more
Date: January 1, 1977
Creator: Prelec, K.
Partner: UNT Libraries Government Documents Department
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Work function dependence and isotope effect in the production of negative hydrogen ions during sputtering of adsorbed hydrogen on Cs covered Mo(100) surfaces

Description: The enhancement of the H/sup -/ yield, during sputtering of adsorbed hydrogen on a Mo(100) surface, by a Cs overlayer was investigated. An exponential dependence of the H/sup -/ yield on the work function was observed for a wide range of Cs coverages. A simple electron tunneling model was proposed. A large reduction in the ion yield was also observed when D/sub 2/ replaced H/sub 2/ as the adsorbate.
Date: January 1, 1977
Creator: Yu, M. L.
Partner: UNT Libraries Government Documents Department
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Residual stresses in Peach Bottom test elements analysis vs experiment

Description: Operating stresses and residual shutdown stresses in fuel test elements irradiated in the Peach Bottom Reactor were calculated with finite element methods. Calculations of deformation and stress due to primary loads were also made. Results of the calculations were used to develop an experimental analysis of graphite fuel and reflector elements. Measured deflections and fracture loads were then compared with predictions made with the analytical methods and data to be verified.
Date: March 1, 1977
Creator: Homeyer, W. G.; Tzung, F. K. & Chiang, D. D.
Partner: UNT Libraries Government Documents Department
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Negative-ion-based neutral beams and upgraded fusion devices (TFTR, MFTF)

Description: The development of negative-ion-based (H/sup -/, D/sup -/) neutral beams for TFTR and MFTF is discussed. Problems with existing equipment include providing beam current and current density, voltage holding, and gas pumping. The problem of stripping the D/sup -/ is described; it is concluded that photodetachment would be desirable to prevent formation of high-energy D/sup +/. Estimates of the parameters associated with photodetachment show it may be feasible although a detailed study will be req… more
Date: November 29, 1977
Creator: Hooper, E. B. Jr. & Fink, J. H.
Partner: UNT Libraries Government Documents Department
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Review of some past and present powder metallurgy programs at the Los Alamos Scientific Laboratory

Description: Powder metallurgy programs at LASL are reviewed. Topics covered include: KlWl reactor fuel elements; Phoebus reactor fuel elements, criticality control and poison plate material, structural composites for fuel element supports, and heat shields for fuel element supports; thermionic emitter reactor uranium carbide--zirconium carbide fuel pins, and molybdenum--uranium oxide fuel pins; laser and electron beam fusion targets; and current work in MHD components. (GHT)
Date: January 1, 1977
Creator: Sheinberg, H.
Partner: UNT Libraries Government Documents Department
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Profiling hydrogen in materials using ion beams

Description: Over the last few years many ion beam techniques have been reported for the profiling of hydrogen in materials. Nine of these were evaluated using similar samples of hydrogen ion-implanted into silicon. When possible the samples were analyzed using two or more techniques to confirm the ion-implanted accuracy. The results of this analysis which has produced a consensus profile of H in silicon which is useful as a calibration standard are reported. The analytical techniques used have capabilities… more
Date: January 1, 1977
Creator: Ziegler, J.F.; Wu, C.P. & Williams, P.
Partner: UNT Libraries Government Documents Department
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Preliminary design of the High Intensity Synchrotron (HIS) for the proposed Intense Pulsed Neutron Source Facility (IPNS) at Argonne

Description: A brief description is given of the synchrotron design for an Intense Pulsed Neutron Source proposed as a national facility for condensed matter research using neutron scattering and radiation damage methods. The discussion includes: (1) H/sup -/ beam injection; (2) machine parameters; (3) magnetic fields; (4) beam extraction; (5) space charge effects; (6) beam bunching; (7) ring magnets; (8) vacuum chamber; (9) power supply; and (10) rf system. (PMA)
Date: January 1, 1977
Creator: Simpson, J.; Crosbie, E.; Khoe, T.; Foss, M.; Thompson, K. & Bywater, J.
Partner: UNT Libraries Government Documents Department
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Residual stress and strain examination in Peach Bottom fuel test elements

Description: An examination of residual stresses and strains has been carried out experimentally on structural graphite components removed from Peach Bottom High-Temperature Gas-Cooled Reactor (HTGR) fuel elements. The purpose of this work is to confirm predicted stress distributions. Twenty-nine teledial fuel elements (of six- and eight-hole design) were irradiated in the Peach Bottom HTGR to fluences of less than or equal to 4 x 10/sup 25/ n/m/sup 2/ (E greater than 29 fJ) and time-average temperatures up… more
Date: May 20, 1977
Creator: Wallroth, C. F.; Miller, C. M. & Saurwein, J. J.
Partner: UNT Libraries Government Documents Department
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