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Recent US target-physics-related research in heavy-ion inertial fusion: simulations for tamped targets and for disk experiments in accelerator test facilities

Description: Within the last few years, there have also appeared in the Heavy-Ion Fusion literature several studies of targets which have outer tampers. One-dimensional simulations indicate higher target gains with a judicious amount of tamping. But for these targets, a full investigation has not been carried through in regards to conservative criteria for fluid instabilities as well as reasonable imperfections in target fabrication and illumination symmetry which all affect target ignition and burn. Compar… more
Date: June 24, 1982
Creator: Mark, J.W.K.
Partner: UNT Libraries Government Documents Department
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Time-Dependent Two-Dimensional Radiation Hydrodynamics of Accreting Matter Onto Highly Magnetized Neutron Stars

Description: We present for the first time, the self-consistent solution of the two-dimensional, time-dependent equations of radiation-hydrodynamics governing the accretion of matter onto the highly magnetized polar caps of luminous x-ray pulsars. The calculations show a structure in the accretion column very different from previous one-zone uniform models. We have included all the relevant magnetic field corrections to both the hydrodynamics and the radiative transport. We include a new theory for the diff… more
Date: November 24, 1989
Creator: Klein, R.I. (California Univ., Los Angeles, CA (USA). Dept. of Astronomy Lawrence Livermore National Lab., CA (USA) California Univ., Los Angeles, CA (USA). Inst. of Geophysics and Planetary Physics) & Arons, J. (California Univ., Berkeley, CA (USA). Dept. of Astronomy California Univ., Los Angeles, CA (USA). Inst. of Geophysics and Planetary Physics CEA Centre d'Etudes Nucleaires de Saclay, 91 -
Partner: UNT Libraries Government Documents Department
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/sup 56/Ni and the light curve of Type I supernova

Description: The explanation of SN Type I by radioactive decay of /sup 56/Ni requires a relatively small value of the transparency function M/sub ej//v/sub 9//sup 2/ = 0.22 in units of M/sub solar/'s and 10/sup 9/ cm s/sup -1/ to explain the light curve. A minimum mass of /sup 56/Ni is required to explain the peak and near peak luminosity. Subsequent radioactive decay energy must escape in some other form than optical light in order to explain the rapid early and late time decay. Early ultraviolet and infra… more
Date: July 24, 1980
Creator: Colgate, S.A. & Petschek, A.G.
Partner: UNT Libraries Government Documents Department
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Evaluation of soil damping techniques used in soil structure interaction analysis of a nuclear power plant

Description: A prediction of dynamic soil properties at the site of a nuclear power plant plays a very important role in the seismic analysis of the facility. Conventional modal analysis procedures can accommodate virtually any range of equivalent elastic soil stiffness which is used to characterize the site. However, high radiation damping associated with energy dissipation in the soil half-space is difficult to accommodate in an elastic modal solution to the dynamic problem. Several methods are available … more
Date: February 24, 1982
Creator: Nelson, T.A.
Partner: UNT Libraries Government Documents Department
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Scale effects in sliding friction: An experimental study

Description: Solid friction is considered by some to be a fundamental property of two contacting materials, while others consider it to be a property of the larger tribosystem in which the materials are contained. A set of sliding friction experiments were designed to investigate the hypothesis that the unlubricated sliding friction between two materials is indeed a tribosystems-related property and that the relative influence of the materials properties or those of the machine on friction varies from one s… more
Date: July 24, 1991
Creator: Blau, P.J.
Partner: UNT Libraries Government Documents Department
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Energy balance measurements for Shiva

Description: The Lawrence Livermore Laboratory Shiva laser-target interaction facility is designed for experiments at 20 to 30 terawatts. At this power level there will be larger fluxes of neutrons, x-rays, electrons and ions than have been previously measured. The measurements of energy converted into the various reaction products is crucial both in target design and performance analysis of the actual experiment. The total energy absorbed is measured by a box calorimeter surrounding the target except for b… more
Date: October 24, 1977
Creator: Glaros, S.S.; Rupert, V.C.; Gunn, S.R.; Phillion, D.W. & Kornblum, H.N.
Partner: UNT Libraries Government Documents Department
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Nuclear interactions of heavy ions

Description: A possible source of preheat for heavy ion driven inertial fusion targets is the production of fast precursors by nuclear interactions between the incident heavy ions and the outer parts of the target. A model has been developed which roughly describes these interactions for all beam-target combinations for all incident energies. This interaction model has been applied to a specific capsule design. The resultant preheat is an order of magnitude below the level which could impair target performa… more
Date: February 24, 1982
Creator: Tabak, M. & Bangerter, R.
Partner: UNT Libraries Government Documents Department
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Wear and corrosion performance of metallurgical coatings in sodium

Description: The friction, wear, and corrosion performance of several metallurgical coatings in 200 to 650/sup 0/C sodium are reviewed. Emphasis is placed on those coatings which have successfully passed the qualification tests necessary for acceptance in breeder reactor environments. Tests include friction, wear, corrosion, thermal cycling, self-welding, and irradiation exposure under as-prototypic-as-possible service conditions. Materials tested were coatings of various refractory metal carbides in metall… more
Date: April 24, 1980
Creator: Johnson, R. N. & Farwick, D. G.
Partner: UNT Libraries Government Documents Department
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Shiva optical diagnostics

Description: In the laser fusion program at Lawrence Livermore Laboratory, no target experiment is complete unless it is complemented by careful measurements of the laser pulse that irradiates the target. For this purpose, an incident beam diagnostics (IBD) package has been designed for the Shiva laser. The package will furnish data on items such as the total energy and the focusable energy out of the laser chain, and the spatial and temporal energy and power distribution at the target plane. Understanding … more
Date: October 24, 1977
Creator: Rienecker, F.; Kobierecki, M.; Ozarski, R.; Seppala, L.; Manes, K. & Merritt, B.
Partner: UNT Libraries Government Documents Department
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Mechanical design of the Tandem Mirror Experiment Upgrade vacuum system

Description: The Tandem Mirror Experiment Upgrade (TMX Upgrade) vacuum system uses most of the vacuum system from the original TMX and substantially increases its capabilities. The vacuum system provides the main structure for the experimental apparatus, as well as providing and maintaining the vacuum environment. The vacuum vessel provides the structure supporting all magnets, as they are contained inside the vacuum vessel, all of the neutral-beam injectors, and the various diagnostics. The vessel provides… more
Date: September 24, 1981
Creator: Lang, D. D.; Calderon, M. O.; Thomas, S. R. & Garner, D. R.
Partner: UNT Libraries Government Documents Department
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Hadron masses in lattice gauge theories: The inclusions of dynamical fermions

Description: Hadron masses are calculated on an 8/sup 3/ /times/ 16 lattice using four flavors of staggered fermion to generate the gauge configurations, but using Wilson fermions to calculate the hadron propagators. The identification of a value of the Wilson hopping parameter with the value of the bare quark mass used in the simulations is discussed.
Date: November 24, 1987
Creator: Richards, D.G.
Partner: UNT Libraries Government Documents Department
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Tandem mirror fusion-fission hybrid studies

Description: Initial tandem mirror hybrid studies predict the ability to produce large amounts of fissile fuel (2 to 7 tons U233 per year from a 4000 MW plant) at a cost that adds less than 25% to the cost of power from a LWR.
Date: April 24, 1980
Creator: Lee, J. D.
Partner: UNT Libraries Government Documents Department
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High performance inertial fusion targets

Description: Inertial confinement fusion (ICF) designs are considered which may have very high gains (approximately 1000) and low power requirements (<100 TW) for input energies of approximately one megajoule. These include targets having very low density shells, ultra thin shells, central ignitors, magnetic insulation, and non-ablative acceleration.
Date: August 24, 1977
Creator: Nuckolls, J.H.; Bangerter, R.O.; Lindl, J.D.; Mead, W.C. & Pan, Y.L.
Partner: UNT Libraries Government Documents Department
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Pion induced double-charge exchange above the resonance

Description: The zero degree excitation function for ({pi}{sup +}, {pi}{sup -}) is calculated for pion energies of 300 to 1400 MeV assuming a sequential mechanism. The cross section around 1225 MeV is 10{sup 4} smaller than at 800 MeV. Experiments at this energy should be ideal for searches for effects due to exchange currents, and other non-conventional mechanisms. 15 refs.
Date: October 24, 1989
Creator: Oset, E.; Strottman, D. (Valencia Univ. (Spain). Dept. de Fisica Teorica & Los Alamos National Lab., NM (USA))
Partner: UNT Libraries Government Documents Department
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Optical coatings for laser fusion applications

Description: Lasers for fusion experiments use thin-film dielectric coatings for reflecting, antireflecting and polarizing surface elements. Coatings are most important to the Nd:glass laser application. The most important requirements of these coatings are accuracy of the average value of reflectance and transmission, uniformity of amplitude and phase front of the reflected or transmitted light, and laser damage threshold. Damage resistance strongly affects the laser's design and performance. The success o… more
Date: April 24, 1980
Creator: Lowdermilk, W.H.; Milam, D. & Rainer, F.
Partner: UNT Libraries Government Documents Department
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Simulations of intermediate density laser fusion targets: recent progress in design and analysis

Description: The attainment of low-adiabat compression to high final state density is essential for achieving high gain thermonuclear micro-implosions. Using 1- and 2-dimensional numerical simulations with LASNEX, the target performance which can be expected and the limitations imposed by absorption heating, and transport for targets designed to reach 100 x liquid DT density (20g/cm/sup 3/) are discussed. The requirements imposed by the need for low preheat, adequate implosion symmetry, and the behavior of … more
Date: August 24, 1977
Creator: Mead, W. C.; Lindl, J. D.; Nuckolls, J. H.; Larsen, J. T.; Bailey, D. S. & Pan, Y. L.
Partner: UNT Libraries Government Documents Department
open access

Multiple electron capture in close ion-atom collisions

Description: Collisions in which a fast highly charged ion passes within the orbit of K electron of a target gas atom are selected by emission of a K x-ray from the projectile or target. Measurement of the projectile charge state after the collision, in coincidence with the K x-ray, allows measurement of the charge-transfer probability during these close collisions. When the projectile velocity is approximately the same as that of target electrons, a large number of electrons can be transferred to the proje… more
Date: July 24, 1989
Creator: Schlachter, A. S.; Stearns, J. W.; Berkner, K. H.; Bernstein, E. M.; Clark, M. W.; DuBois, R. D. et al.
Partner: UNT Libraries Government Documents Department
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Modeling of transformation toughening in brittle materials

Description: Results from modeling of transformation toughening in brittle materials using a discrete micromechanical model are presented. The material is represented as a two-dimensional triangular array of nodes connected by elastic springs. Microstructural effects are included by varying the spring parameters for the bulk, grain boundaries, and transforming particles. Using the width of the damage zone and the effective compliance (after the initial creation of the damage zone) as measures of fracture to… more
Date: January 24, 1992
Creator: LeSar, R.; Rollett, A.D. (Los Alamos National Lab., NM (United States)) & Srolovitz, D.J. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Materials Science and Engineering)
Partner: UNT Libraries Government Documents Department
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Analysis of dense pusher laser-driven implosions for intermediate densities

Description: Post-shot analysis of targets designed to achieve a diagnosible compression of DT gas to 2. g/cm/sup 3/ or 10 x liquid density is reported. The SHIVA laser provided 15 to 20 TW of 1.06 ..mu..m laser light. Detailed comparisons of diagnostic results with hydro-code calculations are made. Implications for laser light absorption/scattering, thermal conduction, suprathermal electron preheat, implosion symmetry, and pusher-fuel mix are discussed. Uncertainties of the density determination methods ar… more
Date: October 24, 1979
Creator: Mead, W. C.; Orth, C. D.; Bailey, D. S.; McClellan, G. & Estabrook, K. G.
Partner: UNT Libraries Government Documents Department
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Extending the cereus group genomics to putative food-borne pathogens of different toxicity

Description: The cereus group represents sporulating soil bacteriacontaining pathogenic strains which may cause diarrheic or emetic foodpoisoning outbreaks. Multiple locus sequence typing revealed a presencein natural samples of these bacteria of about thirty clonal complexes.Application of genomic methods to this group was however biased due tothe major interest for representatives closely related to B. anthracis.Albeit the most important food-borne pathogens were not yet defined,existing dataindicate that… more
Date: August 24, 2006
Creator: Lapidus, Alla; Goltsman, Eugene; Auger, Sandrine; Galleron, Nathalie; Segurens, Beatrice; Dossat, Carole et al.
Partner: UNT Libraries Government Documents Department
open access

On the Virial Theorem for Interstellar Medium

Description: An attempt has been made to derive a version of the virial integral that would describe average properties of the interstellar medium (ISM). It is suggested to eliminate the (large) contribution of stellar matter by introducing 'exclusion zones' surrounding stars. Such an approach leads to the appearance of several types of additional surface integrals in the general expression. Their contribution depends on the rate of energy and matter exchange between the stars and ISM. If this exchange is w… more
Date: September 24, 2007
Creator: Ryutov, D.
Partner: UNT Libraries Government Documents Department
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