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Nuclear and particle astrophysics

Description: We discuss the physics of matter that is relevant to the structure of compact stars. This includes nuclear, neutron star matter and quark matter and phase transitions between them. Many aspects of neutron star structure and its dependance on a number of physical assumptions about nuclear matter properties and hyperon couplings are investigated. We also discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neuron star masses although few are known a… more
Date: October 31, 1990
Creator: Glendenning, N.K.
Partner: UNT Libraries Government Documents Department
open access

Damage parameters for candidate Fusion Materials Irradiation Test facilities

Description: A comparison was made of damage parameters for carbon, iron, and molybdenum irradiated in spectra for d-Li, spallation, and beam-plasma (d-t) neutron sources and a reference DEMO first wall spectrum. The transmutation results emphasize the need to define the neutron spectra at low energies; only the DEMO spectrum was so defined. The spallation spectra were also poorly defined at high neuron energies; they were too soft to produce the desired gas production rates. The treatments of neutron-induc… more
Date: July 31, 1990
Creator: Doran, D. G.; Mann, F. M. & Greenwood, L. R.
Partner: UNT Libraries Government Documents Department
open access

Applications of neural networks to monitoring and decision making in the operation of nuclear power plants. Summary

Description: Application of neural networks to monitoring and decision making in the operation of nuclear power plants is being investigated under a US Department of Energy sponsored program at the University of Tennessee. Projects include the feasibility of using neural networks for the following tasks: (1) diagnosing specific abnormal conditions or problems in nuclear power plants, (2) detection of the change of mode of operation of the plant, (3) validating signals coming from detectors, (4) review of ``… more
Date: December 31, 1990
Creator: Uhrig, R. E.
Partner: UNT Libraries Government Documents Department
open access

Neutron scattering studies of magnetism in the high-Tc materials

Description: In this paper, I shall attempt to review what has been learned about magnetism in the high-{Tc} family of compounds using neutron scattering techniques. Whether or not it is true that magnetic effects are involved in an essential way in the mechanism for superconductivity in these materials (a point which has not yet been firmly established), they offer fascinating examples for the study of magnetism for its own sake, being realizations of spin {1/2} 2D quantum antiferromagnets. Further, the ra… more
Date: December 31, 1990
Creator: Sinha, S. K.
Partner: UNT Libraries Government Documents Department
open access

Helium accumulation effects using bench marked 0-D model

Description: Helium ``ash`` accumulation is a key issue relative to our ability to achieve a steady-state ignited tokamak. 1-D transport simulations using the BALDUR code have been used to examine the correlation between the global helium particle confinement time and the edge exhaust (or recycling) efficiency. This provides a way to benchmark the widely used 0-D model. In this paper, burn conditions for an ITER-like plasma with various helium edge recycling coefficients are examined.
Date: December 31, 1990
Creator: Hu, S. C. & Miley, G. H.
Partner: UNT Libraries Government Documents Department
open access

Expert system driven fuzzy control application to power reactors

Description: For the purpose of nonlinear control and uncertainty/imprecision handling, fuzzy controllers have recently reached acclaim and increasing commercial application. The fuzzy control algorithms often require a ``supervisory`` routine that provides necessary heuristics for interface, adaptation, mode selection and other implementation issues. Performance characteristics of an on-line fuzzy controller depend strictly on the ability of such supervisory routines to manipulate the fuzzy control algorit… more
Date: December 31, 1990
Creator: Tsoukalas, L. H.; Berkan, R. C.; Upadhyaya, B. R. & Uhrig, R. E.
Partner: UNT Libraries Government Documents Department
open access

Whisper gallery mirrors reflectivities from 100 {angstrom} to 500 {angstrom}

Description: We have examined optical constants and predicted reflectivities of candidate surface coatings for whisper gallery mirrors in the extreme ultraviolet (100 {Angstrom} to 500 {Angstrom}). Previous work of Vinogradov and coworkers have identified the spectral regime near 100-150 {Angstrom} as particularly promising due to the high whisper gallery mirror reflectivities of the noble metals in the vicinity of their Cooper minima in this regime. We confirm this basic result using newer optical data, an… more
Date: December 31, 1990
Creator: Hung, Tsen-Yu & Hagelstein, P. L.
Partner: UNT Libraries Government Documents Department
open access

On Defining the Un-Definable: JETS

Description: A brief summary is presented of the current status of jet studies in hadron-hadron collisions. The primary focus is on those issues that would benefit from comparisons of jet samples obtained from hadron-hadron collisions, from e{sup +}e{sup {minus}} annihilation events at LEP and from deep inelastic collisions at HERA. The important point is that, to perform this comparison properly, the jet various samples must be obtained using the same jet definition.
Date: December 31, 1990
Creator: Ellis, Stephen D.
Partner: UNT Libraries Government Documents Department
open access

Novel methods of copper vapor laser excitation

Description: Microwave and intense electron beam excitation of copper vapor are being investigated to be used in copper vapor lasers for isotope separation. Both methods use copper chloride vapor by heating copper chloride. Helium was used as the buffer gas at 2 to 100 torr. In the microwave system, intense copperlines at 510 nm and 578 nm were observed. Initial electron beam results indicate that light emission follows the beam current.
Date: December 31, 1990
Creator: McColl, W. B.; Ching, H.; Bosch, R.; Brake, M. & Gilgenbach, R.
Partner: UNT Libraries Government Documents Department
open access

Ash accumulation effects using bench marked 0-D model

Description: Ash accumulation is a key issue relative to our ability to achieve D-{sup 3}He ARIES III burn conditions. 1-1/2-d transport simulations using the BALDUR code have been used to examine the correlation between the global ash particle confinement time and the edge exhaust (or recycling) efficiency. This provides a way to benchmark the widely used 0-D model. The burn conditions for an ARIES-III plasma with various ash edge recycling coefficients are examined.
Date: December 31, 1990
Creator: Hu, S. C.; Guo, J. P. & Miley, G. H.
Partner: UNT Libraries Government Documents Department
open access

Proton-proton and proton-antiproton elastic scattering at high energies: Theory, phenomenology, and experiment

Description: This is a brief review of the progress in the understanding, during the past twenty years, of hadronic elastic scattering near the forward direction at high energies. On the basis of quantum gauge field theories, the Pomeron is found to be a branch cut above 1. Using the physical picture that this result implies, phenomenology for proton-proton and antiproton-proton elastic scattering is constructed. Two noteworthy features are that, at high energies, both the total cross section and the ratio … more
Date: December 31, 1990
Creator: Wu, Tai Tsun
Partner: UNT Libraries Government Documents Department
open access

Glancing angle x-ray study of crystallization of amorphous Ge at the Ge-Al interface

Description: The amorphous to crystalline transformations of Ge in Al/Ge thin film couples has been studied using glancing angle EXAFS, x-ray reflectivity and diffraction. It was found that crystallization occurs at a much lower temperature (118--150{degrees}C) than for bulk Ge, and initiates at the Al/Ge interface. X-ray diffraction studies were made at 152{degrees}C to study the kinetics of the reaction. After an initial period we find good agreement with a square root dependence of the time, characterist… more
Date: December 31, 1990
Creator: Heald, S. M.; Jayanetti, J. K. D. & Budhani, R. C.
Partner: UNT Libraries Government Documents Department
open access

Surface decontamination using a teleoperated vehicle and Kelly spray/vacuum system

Description: A commercial teleoperated wheeled vehicle was fitted with a modified commercial spray/vacuum decontamination system to allow floor and wall decontamination of an existing process room in one of the chemical separations areas at the Savannah River Site (SRS). Custom end-of-arm tooling was designed to provide sufficient compliance for routine cleaning operations. An operator console was designed to allow complete control of the vehicle base and are movements as well as viewing operations via mult… more
Date: December 31, 1990
Creator: Zollinger, W. T. & Dyches, G. M.
Partner: UNT Libraries Government Documents Department
open access

Rapid heating tensile tests of solution-annealed Incoloy 903 charged with hydrogen and tritium

Description: Rapid heating tensile tests from room temperature to above 1000{degree}C have been performed on specimens of solution-annealed Incoloy 903 charged with hydrogen and tritium. Absorbed hydrogen had very little effect on tensile properties. Internal helium from radioactive decay of absorbed tritium drastically decreased ductility above 700{degree}C.
Date: December 31, 1990
Creator: Mosley, W. C.
Partner: UNT Libraries Government Documents Department
open access

Remote video radioactive process evaluation, Savannah River Site

Description: Specialized miniature low cost video equipment has been effectively used in a number of remote, radioactive, and contaminated environments at the Savannah River Site (SRS). The equipment and related techniques have reduced the potential for personnel exposure to both radiation and physical hazards. The valuable process information thus provided would not have otherwise been available for use in improving the quality of operation at SRS.
Date: December 31, 1990
Creator: Heckendorn, F. M.
Partner: UNT Libraries Government Documents Department
open access

Determination of noble metals in Savannah River Site high-level radioactive sludge

Description: High-level radioactive sludge at the Savannah River Site (SRS) will be processed at the Defense Waste Processing Facility (DWPF) into durable borosilicate glass wasteforms. The sludges are analyzed for elemental content before processing to ensure compatibility with the glass-making processes. Noble metal fission products in sludge, can under certain conditions, cause problems in the glass melter. Therefore, reliable noble metal determinations are important. The scheme used to measure noble met… more
Date: December 31, 1990
Creator: Coleman, C. J.; Kinard, W. F.; Bibler, N. E.; Bickford, D. F. & Ramsey, W. G.
Partner: UNT Libraries Government Documents Department
open access

Use of the RTMC, a full-scope training simulator clone

Description: The Real Time Modeling Computer (RTMC) is a duplicate implementation of the software from the Savannah River Simulator on an independent hardware system. Such a ``cloned`` software tool allows a wide range of development and support activities to be undertaken independently of the training simulator complex. In addition to the expected simulator support function provided by the RTMC (e.g., deficiency corrections and development of model enhancements), the facility is also used for engineering a… more
Date: December 31, 1990
Creator: Gregory, M. V.; Mann, J. L. & Sundal, H. W.
Partner: UNT Libraries Government Documents Department
open access

Remotely maintained waste transfer pump

Description: Westinghouse Savannah River Company (WSRC) operates the Savannah River Site (SRS) for the Department of Energy (DOE). Waste from the processing of irradiated material is stored in large shielded tanks. Treated liquid wastes are to be transferred from these tanks to the Defense Waste Processing Facility (DWPF) for incorporation in glass suitable for storage in a federal repository. Characteristics of the wastes range from water-like liquid to highly viscous wastes containing suspended solids. Pu… more
Date: December 31, 1990
Creator: Eargle, J. C.
Partner: UNT Libraries Government Documents Department
open access

Low-level liquid waste disposal at the Savannah River Site: A large scale demonstration of saltstone

Description: Lysimeters are large-scale, field experiments used at the Savannah River Site (SRS) to measure the effect of percolating rainfall on the release of contaminants from wasteforms. The saltstone lysimeters described are demonstrations of a disposal concept for a low-level radioactive waste resulting from the processing of high-level defense waste for vitrification. Results from the lysimeters confirm the efficacy of the slag formulation in retaining chromium and technetium. Lysimeter results were … more
Date: December 31, 1990
Creator: Clark, S. B. & Wilhite, E. L.
Partner: UNT Libraries Government Documents Department
open access

A high-efficiency thermoelectric converter for space applications

Description: This paper presents a concept for using high-temperature superconducting materials in thermoelectric generators (SCTE) to produce electricity at conversion efficiencies approaching 50% of the Carrot efficiency. The SCTE generator is applicable to systems operating in temperature ranges of high-temperature superconducting materials and thus would be a low-grade converter. Operating in cryogenic temperature ranges provides the advantage of inherently increasing the limits of the Carrot efficiency… more
Date: December 31, 1990
Creator: Metzger, J. D. & El-Genk, M. S.
Partner: UNT Libraries Government Documents Department
open access

Factors affecting the retention of methyl iodide by iodide-impregnated carbon

Description: Iodide-impregnated activated carbon that had been in use for up to 30 months was studied to characterize those factors that affect its interaction with and retention of methyl iodide. Humidity and competing organic sorbents were observed to decrease the residence time of the methyl iodide on the carbon bed. Additionally, changes in the effective surface area and the loss of iodide from the surface are both important in determining the effectiveness of the carbon for retaining radioactive iodine… more
Date: December 31, 1990
Creator: Hyder, M. L. & Malstrom, R. A.
Partner: UNT Libraries Government Documents Department
open access

Mathematical modeling of radioactive waste glass melter

Description: The radioactive waste glass melter used at Savannah River Site (SRS) is a liquid slurry feed joule-heated ceramic melter. The physical nature of a joule-heated meter is complex and involves interactions between electric, thermal, and flow fields. These interactions take place through strongly temperature-dependent glass properties, natural convection, advection, diffusion, and volumetrically distributed joule heating sources. The cold feed on top of heated glass distabilizes the flow field and … more
Date: December 31, 1990
Creator: Choi, I. G.
Partner: UNT Libraries Government Documents Department
open access

Microwave enhanced pyrochemical reactions of PuO{sub 2}, UO{sub 2}, and U{sub 3}O{sub 8}

Description: Experiments in the high level cells at WSRC have established that PuO{sub 2} has an extremely high absorption factor the microwaves: temperatures in excess of 1000{degrees}C were reached in less than 5 minutes with a multi mode, 2450 MHz, 600 watt, microwave oven. In other microwave heating experiments: stoichiometric compositions of PuO{sub 2}-UO{sub 2} were prepared and U{sub 3}O{sub 8} was reduced to U{sub 4}O{sub g}.
Date: December 31, 1990
Creator: Sturcken, E. F. & McCurry, L. E.
Partner: UNT Libraries Government Documents Department
open access

Processing of tetraphenylborate precipitates in the Savannah River Site Defense Waste Processing Facility

Description: The Savannah River Site has generated 77 million gallons of high level radioactive waste since the early 1950`s. By 1987, evaporation had reduced the concentration of the waste inventory to 35 million gallons. Currently, the wastes reside in large underground tanks as a soluble fraction stored, crystallized salts, and an insoluble fraction, sludge, which consists of hydrated transition metal oxides. The bulk of the radionuclides, 67 percent, are in the sludge while the crystallized salts and su… more
Date: December 31, 1990
Creator: Eibling, R. E.
Partner: UNT Libraries Government Documents Department
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