Resource Type

Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei (open access)

Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei

A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been used to construct sets of discrete states with energy 0 to 1.5 MeV in /sup 176/Lu and /sup 236/Np. These data were used as part of the input for calculation of isomer production cross-section ratios in the /sup 175/Lu(n,..gamma..)/sup 176/Lu and /sup 237/Np(n,2n)/sup 236/Np reactions. In order to achieve agreement with experiment, it has been found necessary to include in the modeled set many rotational bands (35 to 95), which are comprised of hundreds of levels with their gamma-ray branching ratios. It is essential that enough bands be included to produce a representative selection of K quantum numbers in the de-excitation cascade. 20 refs., 3 figs., 3 tabs.
Date: October 5, 1984
Creator: Hoff, R. W.; Gardner, D. G. & Gardner, M. A.
System: The UNT Digital Library
Isomer ratio calculations using modeled discrete levels (open access)

Isomer ratio calculations using modeled discrete levels

Isomer ratio calculations were made for the reactions: /sup 175/Lu(n,..gamma..)/sup 176m,g/Lu, /sup 175/Lu(n,2n)/sup 174m,g/Lu, /sup 237/Np(n,2n)/sup 236m,g/Np, /sup 241/Am(n,..gamma..)/sup 242m,g/Am, and /sup 243/Am(n,..gamma..)/sup 244m,g/Am using modeled level structures in the deformed, odd-odd product nuclei. The hundreds of discrete levels and their gamma-ray branching ratios provided by the modeling are necessary to achieve agreement with experiment. Many rotational bands must be included in order to obtain a sufficiently representative selection of K quantum numbers. The levels of each band must be extended to appropriately high values of angular momentum.
Date: October 16, 1984
Creator: Gardner, M. A.; Gardner, D. G. & Hoff, R. W.
System: The UNT Digital Library
Absolute dipole gamma-ray strength functions for /sup 176/Lu. Supplement (open access)

Absolute dipole gamma-ray strength functions for /sup 176/Lu. Supplement

We have derived absolute dipole strength-function information for /sup 176/Lu from an average resonance capture study of /sup 175/Lu with 2-keV neutrons and from neutron capture cross-section measurements with neutrons from 30 keV to about 1 MeV. We found that we needed to increase our previous estimate of the relative M1/E1 strengths near 5 MeV by a factor of 3 and to revise downward the absolute magnitude of our E1 strength function. We accomplished the latter, while still maintaining continuity with the photonuclear data, by adjusting the one free parameter in our line shape. The present E1 and M1 strengths now seem correct both near the neutron separation energy and also around 1 MeV.
Date: October 16, 1984
Creator: Gardner, D. G.; Gardner, M. A. & Hoff, R. W.
System: The UNT Digital Library
Looking Ahead - Biofuels, H2, & Vehicles: 21st Industry Growth Forum (open access)

Looking Ahead - Biofuels, H2, & Vehicles: 21st Industry Growth Forum

This presentation on the future of biofuels, hydrogen, and hybrid vehicles was presented at NREL's 21st Industry Growth Forum in Denver, Colorado, on October 28, 2008.
Date: October 28, 2008
Creator: Gardner, D.
System: The UNT Digital Library
Ion-implantation doping of silicon carbide (open access)

Ion-implantation doping of silicon carbide

Because of their commercial availability in bulk single crystal form, the 6H- and 4H- polytypes of SiC are gaining importance for high-power, high-temperature, and high-frequency device applications. Selective area doping is a crucial processing step in integrated circuit manufacturing. In Si technology, selective area doping is accomplished by thermal diffusion or ion-implantation. Because of the low diffusion coefficients of most impurities in SiC, ion implantation is indispensable in SiC device manufacturing. In this paper the authors present their results on donor, acceptor, and compensation implants in 6H-SiC.
Date: October 1, 1997
Creator: Gardner, J.; Edwards, A.; Rao, M.V.; Papanicolaou, N.; Kelner, G. & Holland, O.W.
System: The UNT Digital Library
Performance of coils wound from long lengths of surface-coated, reacted, BSCCO-2212 conductor (open access)

Performance of coils wound from long lengths of surface-coated, reacted, BSCCO-2212 conductor

React-before-wind surface-coated BSCCO-2212 is being established as a relatively low cost HTS conductor for practical applications. Quality tape is presently being manufactured in 450-500m lengths at a cost estimated to be 1/3-1/5 of the industry costs of BSCCO-2223 powder-in-tube tape. Robust, mechanically sound coils for applications ranging from NMR insert magnets to transformer windings are being made from this BSCCO-2212 tape. The coils have performed consistently through test and thermal cycling without degradation and as projected from short sample measurements. A hybrid approach, which uses mainly BSCCO- 2212 augmented by BSCCO-2223 conductor in the high radial field end regions, is expected to halve magnet system costs.
Date: October 1996
Creator: Walker, M. S.; Hazelton, D. W. & Gardner, M. T.
System: The UNT Digital Library
Ion-implantation doping in SiC and its device applications (open access)

Ion-implantation doping in SiC and its device applications

The latest ion-implantation results on SiC are presented. The authors have performed nitrogen and phosphorus (N/P) co-implantations to obtain very high n-type carrier concentrations, Si and C bombardments for compensating n-type SiC, and V-implantation for compensating p-type SiC. They have also performed N and Al implantations directly into V-doped semi-insulating 6H-SiC substrates. Vertical p-n junction diodes were made by selective area N, P, and N/P implantations into p-type epitaxial layers grown on 6H-SiC substrates.
Date: October 1, 1997
Creator: Rao, M.V.; Gardner, J.; Edwards, A.; Papanicolaou, N.; Kelner, G.; Holland, O.W. et al.
System: The UNT Digital Library
Draft versus finished sequence data for DNA and protein diagnostic signature development (open access)

Draft versus finished sequence data for DNA and protein diagnostic signature development

Sequencing pathogen genomes is costly, demanding careful allocation of limited sequencing resources. We built a computational Sequencing Analysis Pipeline (SAP) to guide decisions regarding the amount of genomic sequencing necessary to develop high-quality diagnostic DNA and protein signatures. SAP uses simulations to estimate the number of target genomes and close phylogenetic relatives (near neighbors, or NNs) to sequence. We use SAP to assess whether draft data is sufficient or finished sequencing is required using Marburg and variola virus sequences. Simulations indicate that intermediate to high quality draft with error rates of 10{sup -3}-10{sup -5} ({approx} 8x coverage) of target organisms is suitable for DNA signature prediction. Low quality draft with error rates of {approx} 1% (3x to 6x coverage) of target isolates is inadequate for DNA signature prediction, although low quality draft of NNs is sufficient, as long as the target genomes are of high quality. For protein signature prediction, sequencing errors in target genomes substantially reduce the detection of amino acid sequence conservation, even if the draft is of high quality. In summary, high quality draft of target and low quality draft of NNs appears to be a cost-effective investment for DNA signature prediction, but may lead to underestimation …
Date: October 29, 2004
Creator: Gardner, S N; Lam, M W; Smith, J R; Torres, C L & Slezak, T R
System: The UNT Digital Library
New parameterization of the E1 gamma-ray strength function (open access)

New parameterization of the E1 gamma-ray strength function

The giant dipole (GD) parameters of peak energy, width, and cross section were satisfactorily correlated for elements from V to Bi, assuming two overlapping peaks with a separation dependent on deformation. The energy dependence of the GD resonance is assumed to have a Breit-Wigner form, but with an energy-dependent width. The resulting gamma-ray strength function model is used to predict neutron capture cross sections and gamma-ray spectra for isotopes of Ta, Os, and Au. 23 references.
Date: October 18, 1979
Creator: Gardner, D. G. & Dietrich, F. S.
System: The UNT Digital Library
Nonoxide ceramic interactions with uranium or carbon. [Reaction of BN, TiN, HfC, CeS, or Ce2S3 with U, C, BeO, W, or Y2O3] (open access)

Nonoxide ceramic interactions with uranium or carbon. [Reaction of BN, TiN, HfC, CeS, or Ce2S3 with U, C, BeO, W, or Y2O3]

The interaction of possible nonoxide containment materials (including boron nitride, titanium nitride, hafnium carbide, and two cerium sulfides) with uranium or carbon has been examined by thermal analysis techniques. Additionally, nonoxide-ceramic interaction with beryllia, tungsten, or yttria was investigated. Hafnium carbide is the least reactive nonoxide ceramic tested.
Date: October 16, 1978
Creator: Holcombe, C.E.
System: The UNT Digital Library
Multipurpose Use of Geothermal Energy (open access)

Multipurpose Use of Geothermal Energy

The conference was organized to review the non-electric, multipurpose uses of geothermal energy in Hungary, Iceland, New Zealand, United States and the USSR. The international viewpoint was presented to provide an interchange of information from countries where non-electric use of geothermal energy has reached practical importance.
Date: October 9, 1974
Creator: Lienau, Paul J. & Lund, John W.
System: The UNT Digital Library
Fourth conference on radiation protection and dosimetry: Proceedings, program, and abstracts (open access)

Fourth conference on radiation protection and dosimetry: Proceedings, program, and abstracts

This Conference is the fourth in a series of conferences organized by staff members of Oak Ridge National Laboratory in an effort to improve communication in the field of radiation protection and dosimetry. Scientists, regulators, managers, professionals, technologists, and vendors from the United States and countries around the world have taken advantage of this opportunity to meet with their contemporaries and peers in order to exchange information and ideas. The program includes over 100 papers in 9 sessions, plus an additional session for works in progress. Papers are presented in external dosimetry, internal dosimetry, radiation protection programs and assessments, developments in instrumentation and materials, environmental and medical applications, and on topics related to standards, accreditation, and calibration. Individual papers are indexed separately on EDB.
Date: October 1, 1994
Creator: Casson, W. H.; Thein, C. M. & Bogard, J. S.
System: The UNT Digital Library
Formation of H/sup -/ and D/sup -/ Ions by Particle Backscattering From Alkali/Transition Metal Complexes (open access)

Formation of H/sup -/ and D/sup -/ Ions by Particle Backscattering From Alkali/Transition Metal Complexes

The data for negative ion reflection yields is analyzed using a backscattering model for the secondary emission coefficient. The enhancement of the secondary emission coefficient is discussed in terms of reflection, formation, and survival probabilities. The yield of negative ions from alkali/transition metal surfaces by low energy atoms emitted from the ion-source discharge is calculated. Volume production of negative ions generated by plasma-surface interactions in a low-work-function-surface bucket-discharge is discussed.
Date: October 1, 1980
Creator: Hiskes, J. R. & Schneider, P. J.
System: The UNT Digital Library
Effects of cloudy/clear air mixing and droplet pH on sulfate aerosol formation in a coupled chemistry/climate global model (open access)

Effects of cloudy/clear air mixing and droplet pH on sulfate aerosol formation in a coupled chemistry/climate global model

In this paper we will briefly describe our coupled ECHAM/GRANTOUR model, provide a detailed description of our atmospheric chemistry parameterizations, and discuss a couple of numerical experiments in which we explore the influence of assumed pH and rate of mixing between cloudy and clear air on aqueous sulfate formation and concentration. We have used our tropospheric chemistry and transport model, GRANTOUR, to estimate the life cycle and global distributions of many trace species. Recently, we have coupled GRANTOUR with the ECHAM global climate model, which provides several enhanced capabilities in the representation of aerosol interactions.
Date: October 1, 1996
Creator: Molenkamp, C.R.; Atherton, C.A.; Penner, J.E. & Walton, J.J.
System: The UNT Digital Library
RHIC Polarized proton performance in run-8 (open access)

RHIC Polarized proton performance in run-8

During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.
Date: October 6, 2008
Creator: Montag, C.; Bai, M.; MacKay, W. W.; Roser, T.; Abreu, N.; Ahrens, L. et al.
System: The UNT Digital Library
Proceedings of the IMOG (Interagency Manufacturing Operations Group) Numerical Systems Group. 62nd Meeting (open access)

Proceedings of the IMOG (Interagency Manufacturing Operations Group) Numerical Systems Group. 62nd Meeting

This document contains the proceedings of the 62nd Interagency Manufacturing Operations Group (IMOG) Numerical Systems Group. Included are the minutes of the 61st meeting and the agenda for the 62nd meeting. Presentations at the meeting are provided in the appendices to this document. Presentations were: 1992 NSG Annual Report to IMOG Steering Committee; Charter for the IMOG Numerical Systems Group; Y-12 Coordinate Measuring Machine Training Project; IBH NC Controller; Automatically Programmed Metrology Update; Certification of Anvil-5000 for Production Use at the Y-12 Plant; Accord Project; Sandia National Laboratories {open_quotes}Accord{close_quotes}; Demo/Anvil Tool Path Generation 5-Axis; Demo/Video Machine/Robot Animation Dynamics; Demo/Certification of Anvil Tool Path Generation; Tour of the M-60 Inspection Machine; Distributed Numerical Control Certification; Spline Usage Method; Y-12 NC Engineering Status; and Y-12 Manufacturing CAD Systems.
Date: October 1, 1993
Creator: Maes, G. J.
System: The UNT Digital Library
Inertial fusion results from Nova and implication for the future of ICF (open access)

Inertial fusion results from Nova and implication for the future of ICF

A key objective of the US Inertial Confinement Fusion Program is to obtain high yield (100-1000 MJ) implosions in a laboratory environment. This requires high grain from an inertial fusion target from a driver capable of delivering about 10 MJ. Recent results have been sufficiently encouraging that the US Department of Energy is planning for such a capability called the Laboratory Microfusion Facility (LMF). In the past two years, we have conducted implosion-related experiments with approximately 20 kJ of 0.35-{mu}m laser light in 1-ns temporally flat-topped pulses. These experiments were done with the Nova laser, the primary US facility devoted to radiatively driven inertial confinement fusion. Our results show that we can accurately model a significant fraction of the phenomena required to obtain the fuel conditions needed for high gain. Both the x-ray conversion efficiency and the growth of Rayleigh-Taylor hydrodynamic instabilities are shown to be at acceptable levels. Targets designed so that the shape of the stagnated fuel can be imaged show that the x-ray drive in our hohlraums can be made isotropic to better than 3%. With this optimized drive and temporally unshaped laser pulses many critical implosion parameters are measured on targets designed for higher density. Good …
Date: October 1, 1988
Creator: Kilkenny, J. D.; Cable, M. D.; Campbell, E. M.; Coleman, L. W.; Correll, D. L.; Drake, R. P. et al.
System: The UNT Digital Library
Long term modeling of the links between economics, technical progress and environment: Evolution of approaches and new trends (open access)

Long term modeling of the links between economics, technical progress and environment: Evolution of approaches and new trends

This paper examines the evolution of modeling on greenhouse as emissions. The paper briefly highlights the origins and early efforts to model greenhouse gas emissions, efforts subsequent to 1988, and the shape of the next generation of greenhouse gas emissions models. Particular emphasis is placed on the author`s own contributions, including the Edmonds-Reilly Model and the second generation model.
Date: October 1, 1992
Creator: Edmonds, J.
System: The UNT Digital Library
Long term modeling of the links between economics, technical progress and environment: Evolution of approaches and new trends (open access)

Long term modeling of the links between economics, technical progress and environment: Evolution of approaches and new trends

This paper examines the evolution of modeling on greenhouse as emissions. The paper briefly highlights the origins and early efforts to model greenhouse gas emissions, efforts subsequent to 1988, and the shape of the next generation of greenhouse gas emissions models. Particular emphasis is placed on the author's own contributions, including the Edmonds-Reilly Model and the second generation model.
Date: October 1, 1992
Creator: Edmonds, J.
System: The UNT Digital Library
Line intensities for diagnosing laser-produced plasmas (open access)

Line intensities for diagnosing laser-produced plasmas

We have measured relative line intensities of the K x-ray spectra of Si, Cl, and Ca from laser-produced plasmas to assess their usefulness as a plasma diagnostic. The different elements are added at low concentrations to CH disks which are irradiated at 5 x 10/sup 14/ W/cm/sup 2/ with a 0.53 ..mu..m laser pulse of 20 Joules at 1 nsec. The concentration of each element is kept low in order not to change the Z of the plasma, and therefore the plasma dynamics. The various spectra are measured with a time-resolved spectrograph to obtain line intensities as a function of time over the length of the laser pulse. These relative intensities of various He-like and H-like lines are compared with calculations from a steady-state level population code. The results give good consistency among the various line ratios. Agreement is not as good for analysis of the Li-like satellite lines. Modelling of the Li-like lines need further investigation. 10 references, 9 figures.
Date: October 31, 1983
Creator: Kauffman, R.L.; Matthews, D.L.; Lee, R.W.; Whitten, B.L. & Kilkenny, J.D.
System: The UNT Digital Library
Laser plasma interactions in hohlraums (open access)

Laser plasma interactions in hohlraums

Lasers plasma instabilities are an important constraint in x-ray driven inertial confinement fusion. In hohlraums irradiated with 1.06 {mu}m light on the Shiva laser, plasma instabilities were extremely deleterious, driving the program to the use of shorter wavelength light. Excellent coupling has been achieved in hohlraums driven with 0.35 {mu}m light on the Nova laser. Considerable attention is being given to the scaling of this excellent coupling to the larger hohlraums for an ignition target. Various instability control mechanisms such as large plasma wave damping and laser beam incoherence are discussed, as well as scaling experiments to check the instability levels.
Date: October 5, 1994
Creator: Kruer, W.L.
System: The UNT Digital Library
Comments on ``Use of conditional simulation in nuclear waste site performance assessment`` by Carol Gotway (open access)

Comments on ``Use of conditional simulation in nuclear waste site performance assessment`` by Carol Gotway

This paper discusses Carol Gotway`s paper, ``The Use of Conditional Simulation in Nuclear Waste Site Performance Assessment.`` The paper centers on the use of conditional simulation and the use of geostatistical methods to simulate an entire field of values for subsequent use in a complex computer model. The issues of sampling designs for geostatistics, semivariogram estimation and anisotropy, turning bands method for random field generation, and estimation of the comulative distribution function are brought out.
Date: October 1, 1993
Creator: Downing, D. J.
System: The UNT Digital Library
Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films (open access)

Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Amorphous TiO{sub 2} sol-gel films are irreversibly transformed to a crystalline anatase phase when heated to temperatures in excess of 575 K or subjected to intense pulsed or CW laser irradiation. The laser-induced transformation is initiated as a result of impurity absorption and subsequent heating, and results in densification and relative changes in compressive stress of the film. Isothermally annealed films exhibit a decrease in compressive stress as crystallization proceeds while an increase in compressive stress followed by a decrease in stress is observed when crystallization is laser-induced. Raman spectroscopy has been used to characterize the crystallization ingrowth kinetics and is used in this work as a real time probe of both film temperature and localized stress which can be evaluated from shifts in lattice phonon frequencies measured in real time during laser irradiation. The laser not only induces the phase transformation but excites inelastic Raman scattering from which film stress and temperature can be estimated. A second approach for the determination of these parameters requires incorporation of a thin ruby film between the titania and silica substrate. Here, the wavelength shift of the laser-induced ruby fluorescence can be used to quantify interfacial stress; the fluorescence lifetime measurements are used …
Date: October 1, 1991
Creator: Exarhos, G. J.; Hess, N. J. & Wood, S.
System: The UNT Digital Library
Proximal potentially seismogenic sources for Sandia National Laboratories, Albuquerque, New Mexico (open access)

Proximal potentially seismogenic sources for Sandia National Laboratories, Albuquerque, New Mexico

Recent geologic and geophysical investigations within the Albuquerque Basin have shed light on the potentially seismogenic sources that might affect Sandia National Laboratories, New Mexico (SNL/NM), a multi-disciplinary research and engineering facility of the US Department of Energy (DOE). This paper presents a summary of potentially seismogenic sources for SNL/NM, emphasizing those sources within approximately 8 kilometers (km) of the site. Several significant faults of the central Rio Grande rift transect SNL/NM. Although progress has been made on understanding the geometry and interactions of these faults, little is known of the timing of most recent movement or on recurrent intervals for these faults. Therefore, whether particular faults or fault sections have been active during the Holocene or even the late Pleistocene is undocumented. Although the overall subdued surface expression of many of these faults suggests that they have low to moderate slip rates, the proximity of these faults to critical (e.g., nuclear) and non-critical (e.g., high-occupancy, multistory office/light lab) facilities at SNL/NM requires their careful examination for evaluation of potential seismic hazard.
Date: October 1, 1995
Creator: Gibson, J. Duane
System: The UNT Digital Library