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Intermediate mass fragment emission from 8 to 40 MeV/u

Description: Experimental data for fragmentation in the reactions /sup 93/Nb = /sup 9/Be, /sup 12/C, and /sup 27/Al are presented. Data were obtained from the LBL BEVALAC (25 to 40 MeV/u), GSI Unilac (11 to 18 MeV/u) and LBL SuperHILAC. These measurements imply, that over a large range of bombarding energies, intermediate mass fragments are produced by the bineary decay of a compound nucleus-like system. At low bombarding energies, these systems are associated with a complete fusion reaction, whereas for th… more
Date: February 1, 1986
Creator: Charity, R. J.; McMahan, M. A.; Bowman, D. R.; Liu, Z. H.; McDonald, R. J.; Wozniak, G. J. et al.
Partner: UNT Libraries Government Documents Department
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Application of the implicit TENSOR code to studies of containment of undergound nuclear tests

Description: The TENSOR code, a two-dimensional finite-difference code, has been used extensively for the solution of stress wave propagation problems in materials, particularly those associated with the containment of underground nuclear test. These problems are typically characterized by shock waves at early times and by nearly incompressible flow at later times. To address this type of problem more economically, an implicit Newmark time integration has been implemented. Implicit differencing requires the… more
Date: February 1, 1982
Creator: Burton, D.E.; Bryan, J.B.; Lettis, L.A. Jr. & Rambo, J.T.
Partner: UNT Libraries Government Documents Department
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Rock Properties and Their Effect on Thermally-Induced Displacements and Stresses

Description: A discussion is given of the importance of material properties in the finite-element calculations for thermally induced displacements and stresses resulting from a heating experiment in an in-situ granitic rock, at Stripa, Sweden. Comparisons are made between field measurements and finite element method calculations using (1) temperature independent, (2) temperature dependent thermal and thermomechanical properties and (3) in-situ and laboratory measurements for Young's modulus. The calculation… more
Date: February 1, 1980
Creator: Chan, T.; Hood, M. & Board, M.
Partner: UNT Libraries Government Documents Department
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Oxygen-hydrogen meter assembly for use in remote sodium sampling systems

Description: An assembly of an electrolytic oxygen meter and a diffusion type hydrogen meter was designed to fit into the Multipurpose Sampler hardware already installed and operating on the four FFTF sodium systems. One of the key elements in this assembly is a ceramic-metal sealed oxygen sensor which allows use of a metal tube to extend the 51 cm (20 in.) between the sampler top and the flowing sodium region.
Date: February 1, 1980
Creator: Barton, G.B.; Bohringer, A.P. & Yount, J.A.
Partner: UNT Libraries Government Documents Department
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Recent results in the development of a global medium-energy nucleon-nucleus optical-model potential

Description: Initial results are presented for the determination of a global medium-energy nucleon-nucleus phenomenological optical-model potential using a relativistic Schroedinger representation. The starting point for this work is the global phenomenological optical-model potential of Schwandt )ital et al.), which is based on measured elastic scattering cross sections and analyzing power for polarized protons ranging from 80 to 180 MeV. This potential is optimally modified to reproduce experimental proto… more
Date: February 1, 1988
Creator: Madland, D.G.
Partner: UNT Libraries Government Documents Department
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Heavy-ion radiography and heavy-ion computed tomography

Description: Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis.
Date: February 1, 1982
Creator: Fabrikant, J. I.; Holley, W. R.; McFarland, E. W. & Tobias, C. A.
Partner: UNT Libraries Government Documents Department
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Simulation of reinjection at Cerro Prieto using an idealized two-reservoir model

Description: An idealized two-reservoir model was introduced to explore some of the effects of reinjection in a geothermal field. For both the single-well model and the doublet model, the results indicate that reservoir pressures will be adequately maintained even when an intervening layer of low permeability is present. The same intervening layer may nevertheless be an effective barrier to the movement of cold fronts, due to the effect of gravity and viscosity on the flow of denser colder waters. This show… more
Date: February 1, 1980
Creator: Tsang, C. F.; Mangold, D. C. & Lippmann, M. J.
Partner: UNT Libraries Government Documents Department
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Cluster assembly of hierarchical nanostructures

Description: In the past few years, atom clusters with diameters in the range of 2--20 nm of a variety of materials, including both metals and ceramics, have been synthesized by evaporation and condensation in high-purity gases and subsequently consolidated in situ under ultrahigh vacuum conditions to create nanophase materials. These new utlrafine-grained materials have properties that are often significantly different and considerably improved relative to those of their coarser-grained counterparts owing … more
Date: February 1, 1992
Creator: Siegel, R. W.
Partner: UNT Libraries Government Documents Department
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Beyond the supersymmetric standard model

Description: The possibility of baryon number violation at the weak scale and an alternative primordial nucleosynthesis scheme arising from the decay of gravitations are discussed. The minimal low energy supergravity model is defined and a few of its features are described. Renormalization group scaling and flavor physics are mentioned.
Date: February 1, 1988
Creator: Hall, L.J.
Partner: UNT Libraries Government Documents Department
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Field determinations of HVdc ozone production rates

Description: The environment near a high voltage direct current (HVdc) transmission line experiences corona effects, including the production of oxidants. Field determination of ozone production rates were made at the Bonneville Power Administration (BPA) HVdc Test Facility, the Dalles, Oregon, in fall and winter 1977. A novel micrometeorological profiling technique was used to identify sources of ozone plumes. The results indicate that even during precipitation the atmospheric ozone concentrations from HVd… more
Date: February 1, 1979
Creator: Droppo, J. G.
Partner: UNT Libraries Government Documents Department
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Particel substructure. A common theme of discovery in this century

Description: Some example of modern developments in particel physics are given which demonstrate that the fundamental rules of quantum mechanics, applied to all forces in nature as they became understood, have retained their validity. The well-established laws of electricity and magnetism, reformulated in terms of quantum mechanics, have exhibited a truly remarkable numerical agreement between theory and experiment over an enormous range of observation. As experimental techniques have grown from the top of … more
Date: February 1, 1984
Creator: Panofsky, W.K.H.
Partner: UNT Libraries Government Documents Department
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Purex process operation and performance: 1970 thoria campaign

Description: The Hanford Purex Plant has demonstrated suitability for reprocessing irradiated thoria (ThO/sub 2/) target elements on a campaign basis. A 1965 process test and major production campaigns conducted in 1966 and 1970 recovered nitrate solution form products totaling approximately 565 tons of thorium and 820 kilograms of /sup 233/U. The overall recoveries for the 1970 campaign based on reactor input data were 94.9 percent for thorium and 95.2 percent for uranium. The primary function of the Hanfo… more
Date: February 1, 1978
Creator: Walser, R.L.
Partner: UNT Libraries Government Documents Department
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Mechanical model for ductility loss

Description: A mechanical model was constructed to probe into the mechanism of ductility loss. Fracture criterion based on critical localized deformation was undertaken. Two microstructure variables were considered in the model. Namely, the strength ratio of grain boundary affected area to the matrix, ..cap omega.., and the linear fraction, x, of grain boundary affected area. A parametrical study was carried out. The study shows that the ductility is very sensitive to those microstructure parameters. The fu… more
Date: February 11, 1980
Creator: Hu, W.L.
Partner: UNT Libraries Government Documents Department
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Lithium corrosion/mass transfer test facility

Description: Liquid lithium is a leading candidate as a tritium breeding material for fusion reactors because of its good breeding and heat-transfer characteristics. This paper describes a new experimental facility for investigating the corrosion/mass transfer/deposition mechanisms at characteristic velocities and system temperatures. This test facility, which is constructed of ferritic/martensitic steel (Fe-9Cr-1Mo), simulates conditions projected for a liquid metal heat transport system. The test facility… more
Date: February 1, 1988
Creator: Smith, D. L.; Chopra, O. K. & Hull, A. B.
Partner: UNT Libraries Government Documents Department
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Fermi level dependent native defect formation: Consequences for metal-semiconductor and semiconductor-semiconductor interfaces

Description: The amphoteric native defect model of the Schottky barrier formation is used to analyze the Fermi level pinning at metal/semiconductor interfaces for submonolayer metal coverages. It is assumed that the energy required for defect generation is released in the process of surface back-relaxation. Model calculations for metal/GaAs interfaces show a weak dependence of the Fermi level pinning on the thickness of metal deposited at room temperature. This weak dependence indicates a strong dependence … more
Date: February 1, 1988
Creator: Walukiewicz, W.
Partner: UNT Libraries Government Documents Department
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Effect of organic complexants on the mobility of low-level-waste radionuclides in soils

Description: The effect of certain organic complexants on the distribution of some radionuclides between solution and soil has been measured. The complexants and radionuclides examined are some of those most likely to be present in low-level waste disposal sites; Cs, Sr, Ni, Co, and Eu radionuclides, and EDTA, DTPA, oxalate, and citrate complexants. The effect of complexants was found to vary widely; in some systems there was no effect and in other systems there were large effects. In some cases slow rates … more
Date: February 1, 1982
Creator: Swanson, J.L.
Partner: UNT Libraries Government Documents Department
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Investigation of the oxygen-vacancy (A-center) defect complex profile in neutron irradiated high resistivity silicon junction particle detectors

Description: Distributions of the A-center (oxygen-vacancy) in neutron silicon detectors have been studied using Deep Level Transient Spectroscopy. A-centers have been found to be nearly uniformly distributed in the silicon water depth for medium resistivity (0.1 {minus} 0.2 k{Omega}-cm) silicon detectors. A positive filling pulse was needed to detect the A-centers in high resistivity (>4 k{Omega}-cm) silicon detectors, and this effect was found to be dependent on the oxidation temperature. A discussion of … more
Date: February 1, 1992
Creator: Li, Zheng; Kraner, H.W. (Brookhaven National Lab., Upton, NY (United States)); Verbitskaya, E.; Eremin, V.; Ivanov, A. (AN SSSR, St. Petersburg (Russian Federation). Physico-Technical Inst.); Rattaggi, M. et al.
Partner: UNT Libraries Government Documents Department
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Beryllium Science: US-UK agreement on the use of Atomic Energy for mutual defense

Description: Twenty-seven papers are presented on beryllium supply, production, fabrication, safe handling, analysis, powder technology, and coatings. Separate abstracts have been prepared for the individual papers. (DLC)
Date: February 19, 1988
Creator: Hanafee, J.E. (ed.)
Partner: UNT Libraries Government Documents Department
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Progress report on future accelerators

Description: SLAC intends to pursue high energy physics work in the future along three lines: (1) continued exploration of electron and photon physics on stationary targets; (2) colliding beam physics using electron-positron storage rings; (3) single-pass collider physics with electrons using first the Stanford Linear Collider (SLC) and eventually a single-pass collider operating near the highest practical upper limit for such devices. These long-range plans are discussed.
Date: February 1, 1984
Creator: Panofsky, W.K.H.
Partner: UNT Libraries Government Documents Department
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Selection of fluids for tritium pumping systems

Description: The degradation characteristics of three types of vacuum pump fluids, polyphenyl ethers, perfluoropolyethers and hydrocarbon oils were reviewed. Fluid selection proved to be a critical factor in the long-term performance of tritium pumping systems and subsequent tritium recovery operations. Thermal degradation and tritium radiolysis of pump fluids produce contaminants which can damage equipment and interfere with tritium recovery operations. General characteristics of these fluids are as follow… more
Date: February 1, 1984
Creator: Chastagner, P
Partner: UNT Libraries Government Documents Department
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Spectral modelling of the soft gamma ray repeater

Description: This paper summarizes the results of numerical modelling of the spectra of the soft gamma ray repeater (SGR 1806-20). Parameters of the emission region can be extracted from the spectral fits under the simplistic assumption of isothermal and homogeneous emission layers. Limits on the luminosity distance of the source can also be derived if we make specific interpretations of the low frequency turnover in the observed spectrum. 12 refs., 3 figs.
Date: February 1, 1988
Creator: Liang, E.P.
Partner: UNT Libraries Government Documents Department
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Properties of hydrogen/helium accretion plasmas

Description: We study the properties of impulsively-heated plasmas initially composed of hydrogen and helium. We follow the time-dependent behavior of the ion and electron temperatures, the pair density, and the densities of hydrogen, helium, and nuclei formed in fusion and breakup reactions. We also consider neutron production and escape, and calculate the 0.431 and 0.478 MeV line luminosities from ..cap alpha..-..cap alpha.. fusion reactions, and the 2.22 MeV line luminosity from neutron capture on proton… more
Date: February 1, 1988
Creator: Guessoum, N. & Dermer, C. D.
Partner: UNT Libraries Government Documents Department
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Effects of high beam rates on TPC's

Description: The TPC's (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchroton) were exposed to silicon ion fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to measure the distortion of the electric field caused by positive ions in the drift region. Results of these tests are presented and the consequences for the TPC based experiment at RHIC (Relativistic Heavy Ion Collider) are discussed.
Date: February 6, 1992
Creator: Etkin, A.; Eiseman, S. E.; Foley, K. J.; Hackenburg, R. W.; Longacre, R. S.; Love, W. A. et al.
Partner: UNT Libraries Government Documents Department
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Report of the working group on far-field accelerators

Description: This report describes the work of the Group on Far Field Accelerators. The work was focused on two accelerator schemes, the Inverse Free Electron Laser and the Two Wave Device. The possibilities and limitations of these two accelerators are discussed, as well as some of the requiremenets on the laser necessary to reach very high energies. A conceptual design of a single pass Inverse Free Electron Laser is presented.
Date: February 1, 1982
Creator: Pellegrini, C.
Partner: UNT Libraries Government Documents Department
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