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7,799 Matching Results
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Magnet power system for the Microwave Tokamak Experiment (MTX)
The system configuration, layout, and general philosophy for the MTX magnet power system is described. The vast majority of the magnet power equipment was quite successfully used on the ALCATOR-C experiment at the Massachusetts Institute of Technology. The AC power for the magnet system at MIT was obtained from a 225MVA alternator. The power for the system at LLNL is obtained directly from the local utility's 230 kV line. This installation, therefore, necessitates the addition of a great deal of equipment in ranges from new switchgear in the substation to using existing switchgear obtained from MIT as contractors for intershop electrical isolation as well as safety isolation for personnel entry into the experimental area. Additionally, some discussion is made of the unique layout of this facility and the tradeoffs made to accommodate them. 2 refs., 6 figs.
Date:
October 7, 1987
Creator:
Jackson, M.C. & Musslewhite, R.C.
Object Type:
Article
System:
The UNT Digital Library
Specific heat loading in Nd:glass lasers
The specific thermal load parameter, chi, for xenon flashlamp-pumped Nd:glass gain media is written as a function of neodymium concentration, pump pulse duration, and energy extraction efficiency. The currently available data on radiative and nonradiative decay probabilities of several commercial Nd:glasses are used to calculate and graph specific thermal load parameter values. By factoring these results into performance scaling relationships for zig-zag and disk lasers, specific Nd:glasses can be selected for optimized laser performance.
Date:
August 7, 1985
Creator:
Krupke, W. F.
Object Type:
Report
System:
The UNT Digital Library
Clean gasoline reforming with superacid catalysts
Tasks reported on this term include optimization of chlorided Pt- alumina catalysts, testing of the optimum Pt/Cl alumina catalysts, preparation and testing of zirconia superacid catalyst. (VC)
Date:
May 7, 1992
Creator:
Davis, B. H.
Object Type:
Report
System:
The UNT Digital Library
Positron lifetimes in solids from first principles calculations
We present a first principles method for calculating positron lifetimes in solids, based on self-consistent calculations using the Linear Muffin-Tin Orbital method. Local density approximations are used for both electron-electron and electron-positron interactions. Results are presented for a variety of elemental metals and vacancies to demonstrate the reliability of this approach. Theoretical calculations of positron lifetimes can be used to interpret experimental data. As an examples of this, we interpret our experimental lifetime data for the oxide superconductor Ba{sub 1-x}K{sub x}BiO{sub 3} using calculations based on this method. 12 refs., 3 figs.
Date:
August 7, 1991
Creator:
Sterne, P. A.; O'Brien, J. C.; Howell, R. H. & Kaiser, J. H.
Object Type:
Article
System:
The UNT Digital Library
Thin-thick quadrature frequency conversion
The quadrature conversion scheme is a method of generating the second harmonic. The scheme, which uses two crystals in series, has several advantages over single-crystal or other two crystal schemes. The most important is that it is capable of high conversion efficiency over a large dynamic range of drive intensity and detuning angle.
Date:
February 7, 1985
Creator:
Eimerl, D.
Object Type:
Article
System:
The UNT Digital Library
SPE water electrolysis technology development for large scale hydrogen production. Progress report No. 4, June 15, 1976--September 30, 1976
Porous carbon fiber paper was selected as the cathode membrane and electrode assembly support based on over 1200 hr operational evaluation. Three potential anode supports are under test. All three appear technically satisfactory after 500 to 1200 hr operational evaluation on each. Optimization of molds and molding techniques for a foil backed ribbed carbon collector of bipolar design, including ribbed flow fields, manifolds, ports and sealing surfaces, is in process. Over 2800 hr demonstrated at 300/sup 0/F on platinum screened cell. Over 2200 hr demonstrated at 300/sup 0/F on cell with carbon cloth cathode current collector. Forty-eight hours screening tests of 56 different anode catalysts have been completed. A 500-hr life test program of 12 anode catalyst types which showed promise on the screening tests has been started. Attempts to stabilize RuO/sub x/ for use as an anode catalyst are being pursued. Low loaded cathodes on graphite substrates show performance to within 25 MV of baseline. Optimization of substrate thickness and fabrication procedures is continuing. Twenty-five low loaded anodes catalyst/substrate combinations have all shown poor performance stability with time. Continued development of the grafted TFS membrane has shown greatly improved physical characteristics and encouraging performance for samples in the 25 …
Date:
October 7, 1976
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators
The Argonne Advanced Acceleration Test Facility is designed as a powerful tool to test ideas for very high gradient acceleration schemes based on direct beam excitation of plasmas, metal structures, dielectrics, etc. The characteristic size in these systems is )approximately) 1 cm, corresponding to frequencies )approximately) 10 GHz. The question addressed here is whether the special features of this facility have application as well to the development of components for the more conventional, lower frequency, accelerators now operating or under development. It is suggested that the usefulness of the facility for the development of conventional systems could be enhanced by a provision for longer time delay between driver and witness beam pulses. 9 refs., 2 figs.
Date:
April 7, 1988
Creator:
MacLachlan, J.A.
Object Type:
Report
System:
The UNT Digital Library
Magnetic testing probe
A cylindrical eddy current tube testing probe is disclosed. Current flow in dual electromagnetic coils separated by an eddy current sensing coil is so directed that magnetic fields of the electromagnet coils have components extending in opposite directions axially of the tested tube and components extending radially of the tube which add in the region of the eddy current sensing coil.
Date:
July 7, 1981
Creator:
Scott, G.W. & Chitwood, L.D.
Object Type:
Patent
System:
The UNT Digital Library
LOFT suppression tank spray system piping: heat exchanger BS-H-31 piping modifications
A stress analysis of the piping modification, resulting from relocation of heat exchanger BS-H-31 of the LOFT Blowdown Suppressing Tank Spray System, was performed. The piping, fittings, and supports were found to comply with the criteria of Section III of the ASME Boiler and Pressure Vessel Code, 1974.
Date:
November 7, 1977
Creator:
Blandford, R.K.
Object Type:
Report
System:
The UNT Digital Library
Difficulties with inferring neutron cross sections from charged-particle reactions
We have investigated problems associated with inferring cross sections for neutron reactions on unstable nuclei in the mass-90 region from charged-particle reactions on nearby stable targets. We conclude that effects due to precompound evaporation, isospin, and multiple reaction paths severely limit the circumstances under which charged-particle studies may be directly and easily converted to neutron cross sections of useful accuracy. 4 refs., 2 figs.
Date:
May 7, 1985
Creator:
Gardner, D. G. & Gardner, M. A.
Object Type:
Article
System:
The UNT Digital Library
Procedure for matching synfuel users with potential suppliers. Appendix B. Proposed and ongoing synthetic fuel production projects
To assist the Department of Energy, Office of Fuels Conversion (OFC), in implementing the synthetic fuel exemption under the Powerplant and Industrial Fuel Use Act (FUA) of 1978, Resource Consulting Group, Inc. (RCG), has developed a procedure for matching prospective users and producers of synthetic fuel. The matching procedure, which involves a hierarchical screening process, is designed to assist OFC in: locating a supplier for a firm that wishes to obtain a synthetic fuel exemption; determining whether the fuel supplier proposed by a petitioner is technically and economically capable of meeting the petitioner's needs; and assisting the Synthetic Fuels Corporation or a synthetic fuel supplier in evaluating potential markets for synthetic fuel production. A data base is provided in this appendix on proposed and ongoing synthetic fuel production projects to be used in applying the screening procedure. The data base encompasses a total of 212 projects in the seven production technologies.
Date:
August 7, 1981
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
High pressure gas metering project
The initial research and development of a system that uses high pressure helium gas to pressurize vessels over a wide range of pressurization rates, vessel volumes, and maximum test pressures are described. A method of controlling the mass flow rate in a test vessel was developed by using the pressure difference across a capillary tube. The mass flow rate is related to the pressurization rate through a real gas equation of state. The resulting mass flow equation is then used in a control algorithm. Plots of two typical pressurization tests run on a manually operated system are included.
Date:
July 7, 1980
Creator:
Tripp, L.R.
Object Type:
Report
System:
The UNT Digital Library
Gaseous phase coal surface modification
In this report, we present an improved, feasible and potentially cost effective method of cleaning and beneficiating ultrafine coal. Increased mechanization of mining methods and the need towards depyritization, and demineralization have led to an increase in the quantity of coal fines generated in recent times. For example, the amount of {minus}100 mesh coal occurring in coal preparation plant feeds now typically varies from 5 to 25% of the total feed. Environmental constraints coupled with the greatly increased cost of coal have made it increasingly important to recover more of these fines. Our method chemically modifies the surface of such coals by a series of gaseous phase treatments employing Friedel-Crafts reactions. By using olefins (ethene, propene and butene) and hydrogen chloride catalyst at elevated temperature, the surface hydrophobicity of coal is enhanced. This increased hydrophobicity is manifest in surface phenomena which reflect conditions at the solid/liquid interphase (zeta potential) and those which reflect conditions at the solid/liquid/gas interphases (contact angle, wettability and floatability).
Date:
May 7, 1992
Creator:
Okoh, J.M.; Pinion, J. & Thiensatit, S.
Object Type:
Report
System:
The UNT Digital Library
Hydrodynamick instabilities on ICF capsules
This article summarizes our current understanding of hydrodynamic instabilities as relevant to ICF. First we discuss classical, single mode Rayleigh-Taylor instability, and nonlinear effects in the evolution of a single mode. Then we discuss multimode systems, considering: (1) the onset of nonlinearity; (2) a second order mode coupling theory for weakly nonlinear effects, and (3) the fully nonlinear regime. Two stabilization mechanisms relevant to ICF are described next: gradient scale length and convective stabilization. Then we describe a model which is meant to estimate the weakly nonlinear evolution of multi-mode systems as relevant to ICF, given the short-wavelength stabilization. Finally, we discuss the relevant code simulation capability, and experiments. At this time we are quite optimistic about our ability to estimate instability growth on ICF capsules, but further experiments and simulations are needed to verify the modeling. 52 refs.
Date:
June 7, 1991
Creator:
Haan, S.W.
Object Type:
Article
System:
The UNT Digital Library
Analysis of three-phase power-supply systems using computer-aided design programs
A major concern of every designer of large, three-phase power-supply systems is the protection of system components from overvoltage transients. At present, three computer-aided circuit design programs are available in the Magnetic Fusion Energy (MFE) National Computer Center that can be used to analyze three-phase power systems: MINI SCEPTRE, SPICE I, and SPICE II. These programs have been used at Lawrence Livermore Laboratory (LLL) to analyze the operation of a 200-kV dc, 20-A acceleration power supply for the High Voltage Test Stand. Various overvoltage conditions are simulated and the effectiveness of system protective devices is observed. The simulated overvoltage conditions include such things as circuit breaker openings, pulsed loading, and commutation voltage surges in the rectifiers. These examples are used to illustrate the use of the computer-aided, circuit-design programs discussed in this paper.
Date:
October 7, 1977
Creator:
Oberst, E.F.
Object Type:
Article
System:
The UNT Digital Library
Field-reversal experiments in the mirror fusion test facility (MFTF)
Detailed consideration of several aspects of a field-reversal experiment was begun in the Mirror Fusion Test Facility (MFTF): Model calculations have provided some plausible parameters for a field-reversed deuterium plasma in the MFTF, and a buildup calculation indicates that the MFTF neutral-beam system is marginally sufficient to achieve field reversal by neutral injection alone. However, the many uncertainties indicate the need for further research and development on alternate buildup methods. A discussion of experimental objectives is presented and important diagnostics are listed. The range of parameter space accessible with the MFTF magnet design is explored, and we find that with proper aiming of the neutral beams, meaningful experiments can be performed to advance toward these objectives. Finally, it is pointed out that if we achieve enhanced n tau confinement by means of field reversal, then quasi-steady-state operation of MFTF is conceivable.
Date:
December 7, 1977
Creator:
Shearer, J.W. & Condit, W.C.
Object Type:
Report
System:
The UNT Digital Library
Advanced direct coal liquefaction. Quarterly technical progress report No. 1, September-November 1983
Wyoming subbituminous coal was liquefied using three different two-stage process configurations in bench-scale tests. These process configurations differed in the type of fractionated deashing resid being recycled to the individual stages. The objective of these runs was to determine whether, by recycle of specific resid streams to the thermal stage, the second stage catalyst life could be improved without detrimentally affecting distillate yield or hydrogen consumption. The results indicate that the two-stage process configuration consisting of hydrotreating the Light Deashed Resid and direct recycle of heavy Deashed Resid to the thermal stage produced the best results. This process configuration resulted in a distillate yield of 54 wt % (MAF coal basis) and overall coal conversion in the 93 to 95% range, as measured by pyridine-soluble analytical test while operating in a total distillate mode. These results are very encouraging from the lower rank Wyoming subbituminous coal. Among the three two-stage process configurations tested, the particular process configuration of hydrotreating Light Deashed Resid resulted in the least amount of catalyst deactivation. As a part of this research effort, a test procedure for quick evaluation of various resids and catalysts in terms of coke precursors was also developed. This procedure utilizing as-produced …
Date:
February 7, 1984
Creator:
Paranjape, A.S.
Object Type:
Report
System:
The UNT Digital Library
Development of magnetic mirror systems for nuclear testing applications
Several system studies have concluded that the small size and steady state nature of magnetic mirror systems provide attractive features for nuclear-testing applications. The principle shortcoming of mirror systems is their small data base relative to that of tokamaks. This paper summarizes the present data base and describes experiments that could be carried out with small modifications of existing facilities to explore plasma physics issues associated with the production of high neutron fluxes in magnetic mirror configurations. The experiments would demonstrate physics principles important to such future applications of fusion power neutrons as blanket testing, tritium production, fissile fuel production, or decontamination of high-level radioactive nuclear-reactor wastes.
Date:
August 7, 1986
Creator:
Simonen, T. C.; Futch, A. H. & Kaiser, T. B.
Object Type:
Report
System:
The UNT Digital Library
Suppression of transverse beam breakup modes in an induction accelerator by gas focusing
The effect of beam-generated positive ions on the beam-breakup instability in linear electron accelerators is calculated using simple models. The strongly nonlinear dependence of the ion focusing force on radius makes a complete suppression of the mode growth possible, in contrast to solenoidal focusing. The predicted gas pressures for significant stabilization of the mode growth in a machine configuration like ATA is relatively low (10/sup -5/ to 10/sup -4/ torr), even for high-Q modes.
Date:
April 7, 1980
Creator:
Briggs, R. J.
Object Type:
Report
System:
The UNT Digital Library
Role of human- and animal-sperm studies in the evaluation of male reproductive hazards
Human sperm tests provide a direct means of assessing chemically induced spermatogenic dysfunction in man. Available tests include sperm count, motility, morphology (seminal cytology), and Y-body analyses. Over 70 different human exposures have been monitored in various groups of exposed men. The majority of exposures studied showed a significant change from control in one or more sperm tests. When carefully controlled, the sperm morphology test is statistically the most sensitive of these human sperm tests. Several sperm tests have been developed in nonhuman mammals for the study of chemical spermatotoxins. The sperm morphology test in mice has been the most widely used. Results with this test seem to be related to germ-cell mutagenicity. In general, animal sperm tests should play an important role in the identification and assessment of potential human reproductive hazards. Exposure to spermatotoxins may lead to infertility, and more importantly, to heritable genetic damage. While there are considerable animal and human data suggesting that sperm tests may be used to detect agents causing infertility, the extent to which these tests detect heritable genetic damage remains unclear. (ERB)
Date:
April 7, 1982
Creator:
Wyrobek, A.J.; Gordon, L. & Watchmaker, G.
Object Type:
Article
System:
The UNT Digital Library
An MS-DOS-based program for analyzing plutonium gamma-ray spectra
A plutonium gamma-ray analysis system that operates on MS-DOS-based computers has been developed for the International Atomic Energy Agency (IAEA) to perform in-field analysis of plutonium gamma-ray spectra for plutonium isotopics. The program titled IAEAPU consists of three separate applications: a data-transfer application for transferring spectral data from a CICERO multichannel analyzer to a binary data file, a data-analysis application to analyze plutonium gamma-ray spectra, for plutonium isotopic ratios and weight percents of total plutonium, and a data-quality assurance application to check spectral data for proper data-acquisition setup and performance. Volume 3 contains the software listings for these applications.
Date:
September 7, 1989
Creator:
Ruhter, W. D. & Buckley, W. M.
Object Type:
Report
System:
The UNT Digital Library
Design and development of Stirling engines for stationary power generation applications in the 500 to 3000 horsepower range. First quarterly report
This project is Phase I of a multi-phased program for the design and development of Stirling engines for stationary power generation applications in the 500 to 3000 horsepower range. Phase I comprises the conceptual design and associated cost estimates of a stationary Stirling engine capable of being fueled by a variety of heat sources, with emphasis on coal firing, followed by the preparation of a plan for implementing the design, fabrication and testing of a demonstration engine by 1985. The main effort in Phase I is the generation of state-of-the-art conceptual designs having greatest potential for prototype testing in 1985. The conceptual designs include a heat transport system for integrating the engine heater head with such energy sources as conventional oil/gas combustors, fluidized bed and other coal combustors, and combustors using coal-derived liquid fuels, and low/medium BTU gases. The heat transport systems being investigated include forced convection with gases or liquids, heat pipes, and direct firing. Currently, the leading choice for the solid fuel combustion system is the atmospheric fluidized bed, with low BTU gasification still a viable alternative. Both systems will continue to be evaluated further, but with greater emphasis on FBC. To date, there appears no clear choice …
Date:
January 7, 1980
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Cost effectiveness of long life incandescent lamps and energy buttons
Long-life replacement lamps for the incandescent lamp have been evaluated with regard to their cost effectiveness. The replacements include the use of energy buttons that extend lamp life as well as an adaptive fluorescent circline lamp that will fit into existing incandescent lamp sockets. The initial, operating, and replacement costs for one million lumen hours are determined for each lamp system. It is found that the most important component lighting cost is the operating cost. Using lamps that are less efficient or devices that cause lamps to operate less efficiently are not cost-effective. The adaptive fluorescent circline lamp, even at an initial unit cost of $20.00, is the most cost-effective source of illumination compared to the incandescent lamp and lamp systems examined.
Date:
April 7, 1980
Creator:
Verderber, R. & Morse, O.
Object Type:
Report
System:
The UNT Digital Library
Benchmark cross sections for bottom quark production
A summary is presented of theoretical expectations for the total cross sections for bottom quark production, for longitudinal and transverse momentum distributions, and for b, /bar b/ momentum correlations at Fermilab fixed target and collider energies.
Date:
January 7, 1988
Creator:
Berger, E. L.
Object Type:
Article
System:
The UNT Digital Library