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Experimental aspects of ion acceleration and transport in the Earth's magnetosphere. [Plasmasphere (leV), exo-plasmasphere (leV-lkeV), plasma sheet (1-10 keV), ring current (10-300 keV), trapped radiation belts (>300 keV)]

Description: Major particle population within the Earth's magnetosphere have been studied via ion acceleration processes. Experimental advances over the past ten to fifteen years have demonstrated the complexity of the processes. A review is given here for areas where composition experiments have expanded perception on magnetospheric phenomena. 64 refs., 6 figs., 1 tab. (WRF)
Date: January 1, 1985
Creator: Young, D. T.
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Partner: UNT Libraries Government Documents Department
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Bunched beam neutralization

Description: One of the steps involved in producing an intense ion beam from conventional accelerators for Heavy Ion Fusion (HIF) is beam bunching. To maintain space charge neutralized transport, neutralization must occur more quickly as the beam bunches. It has been demonstrated at BNL that a 60 mA proton beam from a 750 kV Cockcroft--Walton can be neutralized within a microsecond. The special problem in HIF is that the neutralization must occur in a time scale of nanoseconds. To study neutralization on a … more
Date: January 1, 1979
Creator: Gammel, G. M.; Maschke, A. W. & Mobley, R. M.
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Partner: UNT Libraries Government Documents Department
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Nuclear cross sections for light ions on /sup 6/Li. [100 keV to several MeV]

Description: We review our measurements of total and differential cross sections for protons, deuterons and /sup 3/He incident on /sup 6/Li. These are the reactions which are important for evaluating a fusion reactor based on burning /sup 6/Li. Several of these reactions had not previously been measured, and among those that had there were large discrepancies in some cases. We employed several checks in our measurements to verify that the errors (including systematic errors) were 10 to 20%.
Date: January 1, 1980
Creator: Holland, R.E.; Elwyn, A.J.; Davids, C.N.; Meyer-Schuetzmeister, L.; Monahan, J.E.; Mooring, F.P. et al.
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Partner: UNT Libraries Government Documents Department
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Negative ion source and beam development at BNL

Description: Neutral beam injector based on H/sup -/ ions for Tokamak fusion reactors is gradually evolving from the accumulated research results at BNL. Progress is reported on both Penning and magnetron surface plasma ion sources for direct extraction of negative ions. Schemes for transporting and accelerating of the ion beam are also described. Test results of the gas jets for H/sup -/ ..-->.. H/sup 0/ conversion are also included. The next generation of a high energy neutral injector test stand to be… more
Date: January 1, 1978
Creator: Lam, C; Grossman, M; Kovarik, V; Larson, R; McKenzie-Wilson, R; Prelec, K et al.
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Partner: UNT Libraries Government Documents Department
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Gas bubble and damage microstructure in helium implanted nickel. [20 and 500 keV/sup 4/ He/sup +/]

Description: Transmission electron microscopy has been used to study the depth distribution of bubbles (or voids) and dislocation damage in nickel irradiated at 500/sup 0/C with 20- and 500-keV /sup 4/He/sup +/ ions to total doses ranging from 2.9 x 10/sup 15/ to 5 x 10/sup 17/ ions/cm/sup 2/. The size, number density, and volume fraction of bubbles (or voids) were measured from micrographs taken from samples sectioned parallel to the surface normal. The results for 500-keV irradiation show that the peaks i… more
Date: January 1, 1978
Creator: Kaminsky, M.; Das, S.K. & Fenske, G.
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Partner: UNT Libraries Government Documents Department
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Semi-microscopic calculations of elastic, inelastic, and total neutron scattering by /sup 239/Pu

Description: The purpose of the present work is first to investigate the capabilities of a semi-microscopic optical-model potential involving fewer adjustable parameters than phenomenological models and second, to test the sensitivity of this potential to various rotational band assumptions. Our analysis of the model capabilities is performed using experimental elastic, inelastic, and total cross sections from approx. 10 keV to 15 MeV as well as neutron strength functions, and our sensitivity study is perfo… more
Date: January 1, 1984
Creator: Lagrange, C.; Madland, D.G. & Girod, M.
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Partner: UNT Libraries Government Documents Department
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Structural change of graphite during electron irradiation

Description: Highly oriented pyrolytic graphite was irradiated at room temperature with 300-keV electrons. High resolution transmission electron microscopy and electron energy loss spectroscopy were employed to study the structure of electron-irradiated graphite. Results consistently indicated absence of long-range order periodicity in the basal plane, and loose retention of the c-axis periodicity. Structure was modeled based on a mixture of sixfold and non-sixfold atom rings. Formation of non-sixfold atom … more
Date: January 1, 1992
Creator: Koike, J. (Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering) & Pedraza, D.F. (Oak Ridge National Lab., TN (United States))
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Partner: UNT Libraries Government Documents Department
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Time dependent Hartree-Fock theory of ion-atom collisions: application to F/sup 9 +/ + Ne

Description: Atomic collisions at intermediate energies are formulated in terms of a time dependent self-consistent field. Numerical problems which arise in applying the formalism to heavy ions and atoms are discussed. Results are presented on charge capture and ionization in F/sup 9 +/ + Ne collisions.
Date: January 1, 1984
Creator: Bottcher, C.
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Partner: UNT Libraries Government Documents Department
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Pulsed beam chopper for the PSR at LAMPF

Description: A traveling-wave beam chopper has been designed to provide properly structured negative-ion beam to the Proton Storage Ring (PSR) and other LAMPF users. The chopper must provide a 20-mrad kick with pulse rise time <5 ns for the 750-keV H/sup -/ ions in the injector transpoft line. Variable pulse lengths from 15 ns to 750 ..mu..s at repetition rates up to 16.7 MHz must be generated in synchronization with the PSR circulation frequency. Parameter studies led to an optimized design combining good … more
Date: January 1, 1983
Creator: Lunsford, J. S. & Hardekopf, R. A.
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Partner: UNT Libraries Government Documents Department
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Compact 250-kV Injector System for PIGMI

Description: A 250-kV proton injector to be used in the development of a linac suitable for medical applications has been constructed. This injector utilizes a spherical Pierce geometry to produce a converging beam. A gas insulated accelerating column is cantilevered on a grounded vacuum system, with a separate high voltage equipment dome connected to a 300-kV Cockcroft-Walton power supply. The injector can be operated locally or remotely, with the remote control accomplished by a microprocessor system link… more
Date: January 1, 1978
Creator: Hamm, R. W.; Stevens, R. R. Jr.; Mueller, D. W. & Lederer, H. M.
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Partner: UNT Libraries Government Documents Department
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On the HEMP (high-altitude electromagnetic pulse) environment for protective relays

Description: An assessment of the transient environment for protective relays produced by high-altitude electromagnetic pulse (HEMP) events is presented in this paper. Several mechanisms for coupling of HEMP to relay terminals are used to develop estimates of possible HEMP threats to relays. These predicted relay responses to HEMP events are compared to measured data on a solid state based relay's impulse strength. 12 refs., 13 figs., 3 tabs.
Date: January 1, 1990
Creator: Thomas, D. E.; Wiggins, C. M.; Salas, T. M. (BDM International, Inc., Albuquerque, NM (USA)) & Barnes, P. R. (Oak Ridge National Lab., TN (USA))
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Partner: UNT Libraries Government Documents Department
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Radio-frequency quadrupole linear accelerator

Description: The radio-frequency quadrupole (RFQ) is a new linear accelerator concept in which rf electric fields are used to focus, bunch, and accelerate the beam. Because the RFQ can provide strong focusing at low velocities, it can capture a high-current dc ion beam from a low-voltage source and accelerate it to an energy of 1 MeV/nucleon within a distance of a few meters. A recent experimental test at the Los Alamos Scientific Laboratory (LASL) has confirmed the expected performance of this structure an… more
Date: January 1, 1980
Creator: Wangler, T. P. & Stokes, R. H.
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Partner: UNT Libraries Government Documents Department
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Targets produced in mass separators

Description: Isotopically enriched nuclear targets are prepared directly in the electromagnetic mass separators by allowing the resolved ion species to impinge on a suitable substrate. The calutron, a multi-milliampere mass separator, has been successful in producing ion-implanted targets for nuclear research and in the doping of semiconductors. The typical accelerating energy for this method is 40 keV, although this can be increased by using multiply-charged ions. For highly enriched targets from materials… more
Date: January 1, 1980
Creator: Tracy, J. G.
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Partner: UNT Libraries Government Documents Department
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Using the NBS neutron calibration facility. [2 to 144 keV neutrons]

Description: A description of the NBS neutron calibration facility is given, and those aspects of the facility important to potential users are reviewed. The facility consists of a 10 MW heavy water cooled reactor and a /sup 252/Cf source, both with appropriate irradiation provisions for instrument or phantom irradiation. (GHT)
Date: January 1, 1976
Creator: Hoy, J. E.
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Partner: UNT Libraries Government Documents Department
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Measurements of anti W in methane tissue-equivalent gas for protons

Description: A set of measurements of anti W (the quotient of the energy of a directly ionizing particle by the number of ion pairs created as the particle stops) for protons and carbon ions in gases relevant to neutron dosimetry is reported. The results obtained thus far for protons in tissue equivalent gas are presented.
Date: January 1, 1976
Creator: Rohrig, N. & Colvett, R. D.
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Partner: UNT Libraries Government Documents Department
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U-235 neutron fission cross section from 0. 1 to 20. 0 MeV

Description: The status of the U-235 fast neutron fission cross section is discussed based primarily on material contributed and considered at the NEANDC/NEACRP Specialists Meeting on Fast Neutron Fission Cross Sections held at Argonne National Laboratory in June 1976. However, some newer measurements and evaluations are discussed as well. Specifically, recent measurements at ANL over the energy range 0.2 to 8.2 MeV, using several BND's, are reported. Data from the last 10 years are found to be in good agre… more
Date: January 1, 1977
Creator: Poenitz, W. P.
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Partner: UNT Libraries Government Documents Department
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Nonparametric analysis of an international neutron dosimetry intercomparison

Description: An International Neutron Dosimetry Intercomparison (INDI) was carried out in 1973 at the Radiological Research Accelerator Facility (RRAF) of Brookhaven National Laboratory under the sponsorship of the International Commission on Radiation Units and Measurements (ICRU). Fourteen groups of scientists, from six countries, performed measurements to determine the separate neutron and photon (x- and gamma-ray) tissue kermas in free air for four energies of monoenergetic neutrons, 15.1, 5.5, 2.1, and… more
Date: January 1, 1976
Creator: Goodman, L. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Technical progress report, October 1, 1974--September 30, 1975. [Summaries of research activities at Wisconsin Univ]

Description: Six areas of research are reported: I. Equilibrium fractions of D/sup -/ ions when D/sup +/, D/sub 2//sup +/ or D/sub 3//sup +/ ions are incident on a Cs vapor target. II. Charge exchange collisions when hydrogen and deuterium ions are incident on a Cs vapor target, in which the total charge exchange cross sections sigma/sub +/sub 0// for H/sup +/, H/sub 2//sup +/, D/sup +/, D/sub 2//sup +/, are reported. III. Charge exchange cross sections with rare gas ions incident on a Cs vapor target for H… more
Date: January 1, 1976
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Exit charge state dependence of convoy electron production in heavy-ion solid collisions

Description: The dependence of the yield of convoy electrons emitted near the forward direction in collisions involving fast ions and thin solid targets on the emergent projectile charge state is presented and described in terms of primary electron loss events in the solid. The data include a large array of projectiles, projectile energies and charge states, as well as targets ranging in thickness from the non-equilibrium well into the equilibrium thickness region. The description presented is consistent wi… more
Date: January 1, 1986
Creator: Huelskoetter, H. P.; Burgdoerfer, J. & Sellin, I. A.
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Partner: UNT Libraries Government Documents Department
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Measurements of distributions of energy loss and additivity of energy loss for 50 to 150 keV protons in hydrogen and nine hydrogen gases

Description: Detailed measurements of energy-loss distributions were made for 51, 102 and 153 keV protons traversing hydrogen, methane, ethyne, ethene, ethane, propyne, propadiene, propene, cyclopropane and propane. Less detailed measurements were made at 76.5 and 127.5 keV. To simplify comparison with theory, all of the measurements were made at a gas density that gave a 4% energy loss. The mean energy, second central moment (a measure of the width of the distribution) and the third central moment (a measu… more
Date: January 1, 1976
Creator: Thorngate, J. H.
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Partner: UNT Libraries Government Documents Department
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Kerma factors for tissue compositions, compounds and mixtures. [Thermal to 30 MeV]

Description: Tables of calculated kerma factors for neutrons, being prepared for an ICRU report on Neutron Dosimetry for Biology and Medicine, are discussed. The philosophy and limitations of the calculations, some of the problems encountered, and new experimental and theoretical information needed to improve the knowledge of energy transfer to matter are covered. The tables cover the energy range from thermal to 30 MeV and will appear in the ICRU report. (GHT)
Date: January 1, 1976
Creator: Caswell, R. S.; Coyne, J. J. & Randolph, M. L.
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Partner: UNT Libraries Government Documents Department
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Measurement of the neutron total cross section of sodium. [40 keV to 20 MeV]

Description: The transmission of neutrons through a sample of pure sodium was measured in the energy range 40 keV to 20 MeV. The measurement points out several areas for improvement in the sodium evaluation for ENDF/B-V, the most important being the broadening of the minimum at 300 keV.
Date: January 1, 1976
Creator: Larson, D. C.; Harvey, J. A. & Hill, M. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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