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Electron-Impact Ionization Data for the Fe Isonuclear Sequence (open access)

Electron-Impact Ionization Data for the Fe Isonuclear Sequence

Atomic data for the electron-impact ionization of ions in the Fe isonuclear sequence is reviewed. The best available data are identified. Comments are made on current research activities leading to future data for Fe ions. 23 refs., 29 figs., 12 tabs.
Date: November 25, 1986
Creator: Pindzola, M. S.; Griffin, D. C.; Bottcher, C.; Younger, S. M. & Hunter, H. T.
System: The UNT Digital Library
Acute and long term health effects of radiation (open access)

Acute and long term health effects of radiation

This paper covers selected aspects of the acute and long term health effects excluding acute radiation syndrome and carcinogenesis, resulting from exposure to ionizing radiation. The changes addressed in this paper are those witnessed within an organ or whole body rather than at the molecular or even cellular level. They include acute and late health effects. Some of these effects are threshold effects, meaning that the dose must exceed a certain threshold before one sees these effects. Less than the threshold dose results in no observable organ or whole body effect. The severity of the effects correlate directly with the amount of cell damage or cell death that has occurred. 15 refs., 4 figs., 8 tabs.
Date: November 19, 1986
Creator: Voelz, G. L.
System: The UNT Digital Library
Covariances of evaluated nuclear data based upon uncertainty information of experimental data and nuclear models (open access)

Covariances of evaluated nuclear data based upon uncertainty information of experimental data and nuclear models

A straightforward derivation is presented for the covariance matrix of evaluated cross sections based on the covariance matrix of the experimental data and propagation through nuclear model parameters. 10 refs.
Date: November 17, 1986
Creator: Poenitz, W. P. & Peelle, R. W.
System: The UNT Digital Library
Uncertainties in scientific measurements (open access)

Uncertainties in scientific measurements

Some examples of nuclear data in which the uncertainty has been underestimated, or at least appears to be underestimated, are reviewed. The subjective aspect of the problem of systematic uncertainties is discussed. Historical aspects of the data uncertainty problem are noted. 64 refs., 6 tabs.
Date: November 16, 1986
Creator: Holden, N. E.
System: The UNT Digital Library
Production and shielding of x rays from electron beam vapor sources (open access)

Production and shielding of x rays from electron beam vapor sources

Electron-beam vapor sources are now widely used in material processing sciences and coating technologies, such as the semiconductor industry for producing aluminum films on Si wafers; the metallurgical industry for melting, evaporating, and refining metals; and at Lawrence Livermore National Laboratory (LLNL) for vaporizing metals for laser isotope separation applications. Power for these sources ranges from the kW regime in the semiconductor industry to the multi-MW regime in laser separation technology. Operations of these sources can generate copious amounts of x rays by the direct and indirect interactions of the energetic electrons with the target materials. In this paper, we present the results of our calculations regarding the x-ray emission intensity, angular intensity and energy spectrum distribution, and shielding characteristics for vapor sources with acceleration voltages from 10 kV to 60 kV. 4 refs., 12 figs., 2 tabs.
Date: November 14, 1986
Creator: Singh, M.S.
System: The UNT Digital Library
Spin-Waves in the Uniaxial Spin-Glass System Fe1-xMgxCl2 (open access)

Spin-Waves in the Uniaxial Spin-Glass System Fe1-xMgxCl2

We report as inelastic neutron scattering study of the uniaxial dilute antiferromagnets Fe/sub 1-x/Mg/sub x/Cl/sub 2/, for x = 0.3, 0.45 and 0.6. The first two samples have long-range AF order. Their spin-wave peaks are broadened by the exchange fluctuations. The x = 0.6 sample oders like an Ising spin-glass with a very short AF correlation length (xi approx. = 10 A). For wavelength lambda less than or equal to xi, the spin-wave peaks are similar to the dilute antiferromagnets, but for lambda less than or equal to 2xi, the peak shapens up and becomes resolution limited at the zone center. We give a simple explanation of this behavior. 13 refs., 1 fig.
Date: November 12, 1986
Creator: Wong, P. Z.; Yoshizawa, H. & Shapiro, S. M.
System: The UNT Digital Library
Design considerations for a combined synchrotron-light source and heavy-ion storage ring Atomic Physics Facility (open access)

Design considerations for a combined synchrotron-light source and heavy-ion storage ring Atomic Physics Facility

An Atomic Physics Facility (APF) based on the combination of photons produced by a synchrotron light source with heavy ions in a storage ring will open the way to the study of ionic states of almost all elements. The design considerations for such a facility are discussed in terms of the use of synchrotron radiation for photoexcitation and ionization experiments. Design considerations for an APF are given in terms of the accelerator facilities presently available at BNL which include the National Synchrotron Light Source and Tandem Van de Graaff Laboratory. The results show that the concept is valid and therefore that implementation would result in entirely new capabilities for the study of multiply-ionized atoms.
Date: November 10, 1986
Creator: Jones, K. W.; Johnson, B. M.; Meron, M.; Lee, Y. Y.; Thieberger, P. & Thomlinson, W. C.
System: The UNT Digital Library
Materials technology applied to nuclear accelerator targets (open access)

Materials technology applied to nuclear accelerator targets

The continuing requests for both shaped and flat, very low areal density metal foils have led to the development of metallurgical quality, high strength products. Intent of this paper is to show methods of forming structures on various substrates using periodic vapor interruptions, alternating anodes, and mechanical peening to alter otherwise unacceptable grain morphology which both lowers tensile strength and causes high stresses in thin films. The three technologies, physical vapor deposition, electrochemistry, and chemical vapor deposition and their thin film products can benefit from the use of laminate technology and control of grain structure morphology through the use of materials research and technology.
Date: November 10, 1986
Creator: Barthell, Barry L.
System: The UNT Digital Library
Trace Element Measurements Using White Synchrotron Radiation (open access)

Trace Element Measurements Using White Synchrotron Radiation

Synchrotron radiation, when used for x-ray fluorescence (XRF) has several advantages over conventional x-ray sources. Our group at Brookhaven National Laboratory is developing the equipment and expertise to make XRF measurements with synchrotron radiation. The apparatus is briefly described, along with the alignment techniques. Some minimum detectable limits for trace elements in thin biological standards measured with white light irradiations are presented.
Date: November 10, 1986
Creator: Hanson, A. L.; Jones, K. W.; Gordon, B. M.; Pounds, J. G.; Kwiatek, W. M.; Long, G. J. et al.
System: The UNT Digital Library
A Solid state accelerator (open access)

A Solid state accelerator

We present a solid state accelerator concept utilizing particle acceleration along crystal channels by longitudinal electron plasma waves in a metal. Acceleration gradients of order 100 GV/cm are theoretically possible, but channeling radiation limits the maximum attainable energy to 10/sup 5/ TeV for protons. Beam dechanneling due to multiple scattering is substantially reduced by the high acceleration gradient. Plasma wave dissipation and generation in metals are also discussed.
Date: November 6, 1986
Creator: Chen, P. & Noble, R. J.
System: The UNT Digital Library
Solar oscillations, gravitational multipole field of the sun and the solar neutrino paradox (open access)

Solar oscillations, gravitational multipole field of the sun and the solar neutrino paradox

The visual solar oblateness work and the solar seismological work on the internal rotation of the sun are reviewed and their implications concerning the static gravitational multipole moments of the sun are discussed. The results of this work are quite deviant which is indicative of the complexity encountered and of the necessity for continued studies based on a diverse set of observing techniques. The evidence for phase-locked internal gravity modes of the sun is reviewed and the implications for the solar neutrino paradox are discussed. The rather unique possibility for testing the relevance which the phase-locked gravity modes have to this paradox is also noted. The oscillating perturbations in the sun's gravitational field produced by the classified internal gravity modes and the phase-locked modes are inferred from the observed temperature eigenfunctions. Strains of the order of 10/sup -18/ in gravitational radiation detectors based on free masses are inferred for frequencies near 100 ..mu..Hz. The relevance of these findings is discussed in terms of a new technique for use in solar seismological studies and of producing background signals in studies of low-frequency gravitational radiation. 64 refs., 2 figs.
Date: November 4, 1986
Creator: Hill, H.A. & Rosenwald, R.D.
System: The UNT Digital Library
Effect of changes in DOE pricing policies for enrichment and reprocessing on research reactor fuel cycle costs (open access)

Effect of changes in DOE pricing policies for enrichment and reprocessing on research reactor fuel cycle costs

Fuel cycle costs with HEU and LEU fuels for the IAEA generic 10 MW reactor are updated to reflect the change in DOE pricing policy for enrichment services as of October 1985 and the published charges for LEU reprocessing services as of February 1986. The net effects are essentially no change in HEU fuel cycle costs and a reduction of about 8 to 10% in the fuel cycle costs for LEU silicide fuel.
Date: November 3, 1986
Creator: Matos, J. E. & Freese, K. E.
System: The UNT Digital Library
Modeling the Behavior of Optical Elements in Radiation Environments (open access)

Modeling the Behavior of Optical Elements in Radiation Environments

Calculation of heating caused by the deposition of x-rays in thin film optical elements is complicated because the mean free path of photo and autoionization electrons is comparable to the thin film thickness and thus the electron deposition cannot be considered local. This paper describes the modeling in a 1-D code of: (a) x-ray deposition and transport; (b) electron production, deposition and transport; and (c) thermal conduction and transport. X-ray transport is handled by multigroup discrete ordinates, electron transport is done by the method of characteristics, applied to the two term spherical harmonics expansion approximation (P1) to the Spencer-Lewis transport equation, and thermal transport is computed by a simple Richardson extrapolation of a backward Euler solution to the heat conduction equations. Results of a few test cases are presented. 8 refs., 26 figs., 2 tabs.
Date: November 3, 1986
Creator: Barlow, T. A.; Rhoades, C. E. Jr.; Merker, M. & Triplett, J. R.
System: The UNT Digital Library
Automatic bagout system (open access)

Automatic bagout system

Nuclear material entrained wastes are generated at the Plutonium Facility at Los Alamos National Laboratory. These wastes are removed from the glove box lines using the bagout method. This is a manual operation performed by technicians. An automated system is being developed to relieve the technicians from this task. The system will reduce the amount of accumulated radiation exposure to the worker. The primary components of the system consist of a six degree of freedom robot, a bag sealing device, and a small gantry robot. 1 ref., 5 figs.
Date: November 1, 1986
Creator: Whitaker, R. M.
System: The UNT Digital Library
Bounds on Galactic Cold Dark Matter Particle Candidates and Solar Axions From a Ge-Spectrometer (open access)

Bounds on Galactic Cold Dark Matter Particle Candidates and Solar Axions From a Ge-Spectrometer

The ultralow background Ge spectrometer developed by the USC/PNL group is used as a detector of cold dark matter candidates from the halo of our galaxy and of solar axions (and other light bosons), yielding interesting bounds. Some of them are: heavy standard Dirac neutrinos with mass 20 GeV less than or equal to m less than or equal to 1 TeV are excluded as main components of the halo of our galaxy; Dine-Fischler-Srednicki axion models with F/2x/sub e/' less than or equal to 0.5 x 10/sup 7/ GeV are excluded. 22 refs., 7 figs.
Date: November 1, 1986
Creator: Gelmini, G.
System: The UNT Digital Library
Charge transfer and excitation in high-energy ion-atom collisions (open access)

Charge transfer and excitation in high-energy ion-atom collisions

Coincidence measurements of charge transfer and simultaneous projectile electron excitation provide insight into correlated two-electron processes in energetic ion-atom collisions. Projectile excitation and electron capture can occur simultaneously in a collision of a highly charged ion with a target atom; this process is called resonant transfer and excitation (RTE). The intermediate excited state which is thus formed can subsequently decay by photon emission or by Auger-electron emission. Results are shown for RTE in both the K shell of Ca ions and the L shell of Nb ions, for simultaneous projectile electron loss and excitation, and for the effect of RTE on electron capture.
Date: November 1986
Creator: Schlachter, A. S.; Berkner, K. H.; McDonald, R. J.; Stearns, J. W.; Bernstein, E. M.; Clark, M. W. et al.
System: The UNT Digital Library
Charging and corona modifications to the ORNL 25URC accelerator (open access)

Charging and corona modifications to the ORNL 25URC accelerator

A chain-charge monitoring system was first installed in the 25URC accelerator in October 1982, and has provided valuable information about the charging system. Additions to the system during the past year have significantly increased the amount of information provided by the monitor. Cables connecting pickoff wheels and inductors in the terminal were improved to provide higher reliability of the charging system. The tube corona points supplied with the 25URC accelerator had a point-to-plane spacing of 0.175 inches. Our operating experience indicated that the corona currents for the normal gas pressure and voltage range of the accelerator were lower than optimum. Current-voltage characteristics of a three-needle point set were measured at several spacings and gas pressures to provide criteria for ordering new points.
Date: November 1, 1986
Creator: Ziegler, N. F. & McPherson, R. L.
System: The UNT Digital Library
Climatic indicators for estimating residential heating and cooling loads (open access)

Climatic indicators for estimating residential heating and cooling loads

An extensive data base of residential energy use generated with the DOE-2.1A simulation code provides an opportunity for correlating building loads predicted by an hourly simulation model to commonly used climatic parameters such as heating and cooling degree-days, and to newer parameters such as insolation-days and latent enthalpy-days. The identification of reliable climatic parameters for estimating cooling loads and the incremental loads for individual building components, such as changing ceiling and wall R-values, infiltration rates or window areas is emphasized.
Date: November 1, 1986
Creator: Huang, Y. J.; Ritschard, R.; Bull, J. & Chang, L.
System: The UNT Digital Library
Detection of Higgs bosons decaying to bottom quarks (open access)

Detection of Higgs bosons decaying to bottom quarks

Several developments affecting the possibility of Higgs detection are discussed. These include the level of certainty about the t quark mass, Monte Carlo programs to generate both signal and background events, and separation and/or enhancement of heavy quark jets from jets due to light quarks or gluons, and the possibility that the neutral Higgs decay into bottom quarks might be the decay mode of choice for detecting the intermediate mass Higgs. Possible means of detection of an intermediate mass Higgs at the SSC, particularly if a prominent decay mode is to bottom quarks, are examined, using the PYTHIA Monte Carlo program to generate both signal and background events. For the signal, events were generated in which Higgs bosons are created in proton-proton collisions, with the Higgs decaying into bottom quarks. The presence of W or Z bosons, created in the same proton-proton collision, is used to enhance the likelihood of Higgs production and to reduce the potentially enormous background. It is found that the Higgs decay to bottom quarks, if important, would be more favorable for detection of the Higgs than decay to top quarks was found to be because of the smaller background. 3 refs., 4 figs. (LEW)
Date: November 1, 1986
Creator: Gilman, F.J. & Price, L.E.
System: The UNT Digital Library
Development of a polarized deuterium target by spin exchange with optically pumped K (open access)

Development of a polarized deuterium target by spin exchange with optically pumped K

The development of a polarized internal target at an electron store ring is of great interest for studies in nuclear physics. The deuterium nuclei acquire polarization via the hyperfine interaction after electron spin exchange with optically pumped potassium vapor. A high power laser which covers the entire doppler width and hyperfine splitting of the /sup 2/S/sub 1/2/ - /sup 2/P/sub 1/2/ transition in potassium has been developed. Spin relaxation rates for potassium on various wall coatings have been measured. A dri-film surface has been shown to preserve polarization (>100 bounces), be long-lived at elevated temperatures, and to be efficient at preventing deuterium recombination.
Date: November 1, 1986
Creator: Young, L.; Holt, R.J.; Green, M.C. & Kowalcyzk, R.S.
System: The UNT Digital Library
The effect of fabrication variables on the irradiation performance of uranium silicide dispersion fuel plates (open access)

The effect of fabrication variables on the irradiation performance of uranium silicide dispersion fuel plates

The effect of fabrication variables on the irradiation behavior of uranium silicide-aluminum dispersion fuel plates is examined. The presence of minor amounts of metallic uranium-silicon was found to have no detrimental effect, so that extensive annealing to remove this phase appears unnecessary. Uniform fuel dispersant loading, low temperature during plate rolling, and cold-worked metallurgical condition of the fuel plates all result in a higher burnup threshold for breakaway swelling in highly-loaded U/sub 3/Si fueled plates.
Date: November 1, 1986
Creator: Hofman, G. L.; Neimark, L. A. & Olquin, F. L.
System: The UNT Digital Library
The effect of interaction range on the W(001) surface reconstruction phase transition (open access)

The effect of interaction range on the W(001) surface reconstruction phase transition

A model for the W(001) surface reconstruction phase transition is studied to elucidate the dependence of transition temperature on interaction range and other model parameters. For the parameter set chosen extending the range of the interaction without changing the total reconstruction energy increases the model transition temperature somewhat. This reduces a previously reported discrepancy between the experimental transition temperature and that consistent with the calculated reconstruction energy, but only marginally. 12 refs., 1 fig., 1 tab.
Date: November 1, 1986
Creator: Roelofs, L. D. & Wendelken, J. F.
System: The UNT Digital Library
Effect of irradiation on the tensile properties of niobium-base alloys (open access)

Effect of irradiation on the tensile properties of niobium-base alloys

The alloys Nb-1Zr and PWC-11 (Nb-1Zr-0.1C) were selected as prime candidate alloys for the SP-100 reactor. Since the mechanical properties of niobium alloys irradiated to end-of-life exposure levels of about 2 x 10SW neutrons/mS (E > 0.1 MeV) at temperatures above 1300 K were not available, an irradiation experiment (B-350) in EBR-II was conducted. Irradiation creep, impact properties, bending fatigue, and tensile properties were investigated; however, only tensile properties will be reported in this paper. The tensile properties were studied since they easily reveal the common irradiation phenomena of hardening and embrittlement. Most attention was directed to testing at the irradiation temperature. Further testing was conducted at lower temperatures in order to scope the behavior of the alloys in cooldown conditions.
Date: November 1, 1986
Creator: Grossbeck, M.L.; Heestand, R.L. & Atkin, S.D.
System: The UNT Digital Library
Epitaxial film growth study of single crystal V/Ce prepared by molecular-beam epitaxy on sapphire (open access)

Epitaxial film growth study of single crystal V/Ce prepared by molecular-beam epitaxy on sapphire

The growth of epitaxial films of cerium (Ce)/vanadium (V)/on single crystal sapphires (..cap alpha..-Al/sub 2/O/sub 3/) was studied by in-situ reflection high energy electron diffraction and x-ray scattering. For the first time Ce(111) single crystal films was grown on V(110)/Al/sub 2/O/sub 3/(1120) in the Frank-van der Merwe mode. A new epitaxial orientation, different from the well known Nishiyama-Wasserman or Kurdjumov-Sachs orientations is found in the present study. Subsequent V(110) layers grow epitaxially with three equivalent domains.
Date: November 1, 1986
Creator: Homma, Hitoshi; Yang, Kai-Y. & Schuller, Ivan K.
System: The UNT Digital Library