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A 500 kV Photoemission Electron Gun for the CEBAF FEL (open access)

A 500 kV Photoemission Electron Gun for the CEBAF FEL

The proposed FELs at CEBAF require an electron source delivering 120 pC bunches at a repetition rate of 7.485 MHz, corresponding to an average current of 0.9 mA. To meet this requirement we will employ a 500 kV DC photoemission electron gun to produce nominal 100 psec bunches of modest peak current. The subsequent injector system will bunch and accelerate this beam, producing 60 A, 2 psec bunches for the FELs. The photoemission gun will use a negative electron affinity GaAs photocathode, which provides good quantum efficiency and an adequate temporal response. The optical beam will be provided by a frequency doubled Nd:YLF laser system, actively mode locked to a subharmonic of the fundamental accelerator frequency. The principal technical difficulties associated with an electron source of this type involve the operating lifetime of the photocathode, and the operation of a high voltage gun in the presence of the alkali metals necessary to produce the photocathode. Various design a
Date: August 1, 1991
Creator: Sinclair, Charles
Object Type: Report
System: The UNT Digital Library
1991 Yearly calibration of Pacific Northwest Laboratory's gross gamma-ray borehole geophysical logging system (open access)

1991 Yearly calibration of Pacific Northwest Laboratory's gross gamma-ray borehole geophysical logging system

This report describes the 1991 yearly calibration of a gross gamma-ray geophysical pulse logging system owned by the US Department of Energy (DOE) and operated by the Pacific Northwest Laboratory. The calibration was conducted to permit the continued use of this system for geologic and hydrologic studies associated with remedial investigations at the Hanford Site. Primary calibrations to equivalent uranium units were conducted in DOE borehole model standards that reside on the Hanford Site. The calibrations were performed in borehole models SBL/SBH and SBA/SBB, which contain low-equivalent uranium concentrations. Correlations were established based on two similar approaches for relating observed count rate in before- and after-logging field calibrations to equivalent uranium concentrations. A new field source (Ra-20S-82) was fabricated to replace the old source (Ra-20S-204), whose activity led to variable field calibration results previously caused by a nonfixed geometry. A cross-calibration study was performed to compare the operation of the new source relative to the old source. A digitally based collection/recording system was recently acquired, so that many of the procedures were performed with the old analog system and the new digital system to compare the performance of the digital system. 7 refs., 2 figs., 9 tabs.
Date: August 1, 1991
Creator: Arthur, R.J.
Object Type: Report
System: The UNT Digital Library

[20th Annual Opening Ceremony]

Photograph of festival director Jo Ann Andera with former directors Claudia Ball and O. T. Baker at the opening ceremony of the 20th annual Texas Folklife Festival. Festival directors are lined up in front, backed by clusters of colorful balloons. On the left, a man is playing a large drum next to a man who is playing an accordion.
Date: August 1, 1991
Creator: Informedia
Object Type: Photograph
System: The Portal to Texas History
Ab initio calculations on collisions of low energy electrons with polyatomic molecules (open access)

Ab initio calculations on collisions of low energy electrons with polyatomic molecules

The Kohn variational method is one of simplest, and oldest, techniques for performing scattering calculations. Nevertheless, a number of formal problems, as well as practical difficulties associated with the computation of certain required matrix elements, delayed its application to electron--molecule scattering problems for many years. This paper will describe the recent theoretical and computational developments that have made the complex'' Kohn variational method a practical tool for carrying out calculations of low energy electron--molecule scattering. Recent calculations on a number of target molecules will also be summarized. 41 refs., 7 figs.
Date: August 1, 1991
Creator: Rescigno, T. N.
Object Type: Article
System: The UNT Digital Library
Acoustic emissions applications on the NASA Space Station (open access)

Acoustic emissions applications on the NASA Space Station

Acoustic emission is being investigated as a way to continuously monitor the space station Freedom for damage caused by space debris impact and seal failure. Experiments run to date focused on detecting and locating simulated and real impacts and leakage. These were performed both in the laboratory on a section of material similar to a space station shell panel and also on the full-scale common module prototype at Boeing's Huntsville facility. A neural network approach supplemented standard acoustic emission detection and analysis techniques. 4 refs., 5 figs., 1 tab.
Date: August 1, 1991
Creator: Friesel, M. A.; Dawson, J. F.; Kurtz, R. J.; Barga, R. S.; Hutton, P. H. & Lemon, D. K.
Object Type: Article
System: The UNT Digital Library
(Advanced Coal Conversion Process Demonstration Project) (open access)

(Advanced Coal Conversion Process Demonstration Project)

This project will demonstrate an advanced thermal coal drying process coupled with physical cleaning techniques to upgrade high-moisture, low-rank coals to produce a high-quality, low-sulfur fuel. The coal will be processed through two vibrating fluidized bed reactors that will remove chemically bound water, carboxyl groups, and volatile sulfur compounds. After drying, the coal will be put through a deep-bed stratifier cleaning process to effect separation of the pyrite rich ash. The process will enhance low-rank western coals, usually with a moisture content of 25--55%, sulfur content of 0.5--1.5%, and heating value of 5500--9000 Btu/lb by producing a stable, upgraded coal product with a moisture content as low as 1%, sulfur content as low as 0.3%, and heating value up to 12,000 Btu/lb. The 45 ton/hr unit will be located adjacent to a unit train loadout facility at Western Energy Company's Rosebud coal mine near the town of Colstrip in southeastern Montana. The demonstration plant is sized at about one-tenth the projected throughput of a multiple processing train commercial facility. The demonstration drying and cooling equipment is currently commercial size.
Date: August 1, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
[Advanced Coal Conversion Process Demonstration Project]. Technical progress report, April 1, 1991--June 30, 1991 (open access)

[Advanced Coal Conversion Process Demonstration Project]. Technical progress report, April 1, 1991--June 30, 1991

This project will demonstrate an advanced thermal coal drying process coupled with physical cleaning techniques to upgrade high-moisture, low-rank coals to produce a high-quality, low-sulfur fuel. The coal will be processed through two vibrating fluidized bed reactors that will remove chemically bound water, carboxyl groups, and volatile sulfur compounds. After drying, the coal will be put through a deep-bed stratifier cleaning process to effect separation of the pyrite rich ash. The process will enhance low-rank western coals, usually with a moisture content of 25--55%, sulfur content of 0.5--1.5%, and heating value of 5500--9000 Btu/lb by producing a stable, upgraded coal product with a moisture content as low as 1%, sulfur content as low as 0.3%, and heating value up to 12,000 Btu/lb. The 45 ton/hr unit will be located adjacent to a unit train loadout facility at Western Energy Company`s Rosebud coal mine near the town of Colstrip in southeastern Montana. The demonstration plant is sized at about one-tenth the projected throughput of a multiple processing train commercial facility. The demonstration drying and cooling equipment is currently commercial size.
Date: August 1, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advancing liquid metal reactor technology with nitride fuels (open access)

Advancing liquid metal reactor technology with nitride fuels

A review of the use of nitride fuels in liquid metal fast reactors is presented. Past studies indicate that both uranium nitride and uranium/plutonium nitride possess characteristics that may offer enhanced performance, particularly in the area of passive safety. To further quantify these effects, the analysis of a mixed-nitride fuel system utilizing the geometry and power level of the US Advanced Liquid Metal Reactor as a reference is described. 18 refs., 2 figs., 2 tabs.
Date: August 1, 1991
Creator: Lyon, W.F.; Baker, R.B.; Leggett, R.D. (Westinghouse Hanford Co., Richland, WA (United States)) & Matthews, R.B. (Los Alamos National Lab., NM (United States))
Object Type: Report
System: The UNT Digital Library
The Albany News (Albany, Tex.), Vol. 116, No. 8, Ed. 1 Thursday, August 1, 1991 (open access)

The Albany News (Albany, Tex.), Vol. 116, No. 8, Ed. 1 Thursday, August 1, 1991

Weekly newspaper from Albany, Texas that includes local, county, and state news along with extensive advertising.
Date: August 1, 1991
Creator: Lucas, Donnie A.
Object Type: Newspaper
System: The Portal to Texas History
Alignment of the SLC Final Focus system using beam orbits (open access)

Alignment of the SLC Final Focus system using beam orbits

Beam based alignment is being routinely applied in the SLC Final Focus and has proved to be a very useful tool for determining the quality of the zeroth order orbit as defined by various beam line elements. Given the stringent requirement on the beam quality at the interaction point, a well aligned beam line is essential in that it minimizes the confusion which would otherwise arise in the higher order optics, the demand called on the correctors which also serve as optical knobs, and the problem associated with the background radiation. In the SLC final focus we have been relying on an interplay between the field survey and the orbit analysis to achieve this purpose. Mechanical alignment generally provides coordinate information of various beam line elements and offset values inferred from these data and the model of the beam line. Beam based alignment is done mainly by recording the beam orbit under controlled experiment where optical elements or orbit conditions are varied. Due to the complexity of the beamline layout and special power supply configuration in the SLC Final Focus, the latter method is useful only when coupled with off-line analysis which disentangles the data taken at each measurement. In …
Date: August 1, 1991
Creator: Chao, Y.; LeDiberder, F.; Burchat, P.; Kozanecki, W. & Toge, N.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 91, No. 124, Ed. 1 Thursday, August 1, 1991 (open access)

Altus Times (Altus, Okla.), Vol. 91, No. 124, Ed. 1 Thursday, August 1, 1991

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: August 1, 1991
Creator: Lomenick, Rick
Object Type: Newspaper
System: The Gateway to Oklahoma History
Analysis and technology transfer report, 1989 and 1990 (open access)

Analysis and technology transfer report, 1989 and 1990

The buildings sector used 29.6 quadrillion Btus (quads) of energy in 1989, or 36 percent of the total primary energy consumed in the United States. The major uses are for space heating and cooling, water heating, refrigeration, and lighting. Electricity is the dominant fuel, followed by natural gas, petroleum, and other fuels. Although there were dramatic improvements in energy efficiency in this sector from 1975 to 1985, in recent years energy use has grown rapidly. The large growth expected in commercial building floor space and in residential units means that total building-sector energy consumption could increase dramatically by the year 2030. The mission of the US DOE's Office of Building Technologies (OBT) is to lead a national program supporting private sector efforts to improve the energy efficiency of the nation's buildings and to increase their utilization of renewable energy sources. The Office is also responsible for energy efficiency planning and management for Federal buildings as well as buildings-related associated information, financial incentives, and regulatory functions that are determined to be appropriate for the Federal government. To accomplish its goals, OBT plans and conducts research and development to make technologies available and provides information on their effectiveness. The selection and management …
Date: August 1, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Analysis of Possible Stratagems for Enhancing the EOM Power of RTGs for the CRAF Mission (open access)

Analysis of Possible Stratagems for Enhancing the EOM Power of RTGs for the CRAF Mission

Paper presented at the 26th IECEC in Boston, MA August 4-9, 1991. This paper describes the various stratagems investigated and discusses their drawbacks and their effectiveness. The analytical results indicated that a combination of relatively modest RTG modifications that could be implemented in time for the mission could come very close to meeting the CRAF power demand goals specified by JPL. However, since even with the modifications the two RTGs did not provide sufficient margin for possible further growth in power demand, the JPL project team ultimately decided to use 3 RTGs for the CRAF mission also. This had the decisive advantage of eliminating the need for load switching to reduce the power demand peaks. The purpose of this paper is to document the various power enhancement schemes analyzed and their computed effectiveness, for possible future applications. There are three copies in the file.
Date: August 1, 1991
Creator: Schock, Alfred; Or, Chuen T & Noravian, Heros
Object Type: Report
System: The UNT Digital Library
Analysis of sediment, water, and biological samples from the Bay Farm Borrow Area, San Francisco Bay, California (open access)

Analysis of sediment, water, and biological samples from the Bay Farm Borrow Area, San Francisco Bay, California

The Bay Farm Borrow Area (BFBA) of San Francisco Bay, California, is under consideration as a dredged-material disposal site by the US Army Corps of Engineers (USACE). As part of the analysis of the site, information is required on the quality of benthic biota, sediment, and water in the BFBA. The objective of this report was to provide data on infauna communities, sediment, and water chemistry from samples collected from the BFBA. The samples were collected, and the data will be analyzed by Science Applications International (SAIC). A total of four samples for sediment chemistry, four samples for water chemistry, and 7 samples for infauna communities were analyzed by the Battelle/Marine Sciences Laboratory (MSL). Water analyses included tests for dissolved organic carbon, total suspended solids, four metals, butyltins, polychlorinated biphenyls (PCBs), chlorinated pesticides, polynuclear aromatic hydrocarbons (PAHs), four phenols, and total phenol. Sediment samples were analyzed for percent solids, total organic carbon, total oil and grease, total petroleum hydrocarbons, grain size, 10 metals, butyltins, PCBs, chlorinated pesticides, PAHs, four phenols, and total phenol. The data along with controls and spike recovery analyses, are presented in tables, and the results are discussed in the text. The quality assurance/quality control criteria were …
Date: August 1, 1991
Creator: Thom, R. M. & Lefkovitz, L. F.
Object Type: Report
System: The UNT Digital Library
Analysis techniques for momentum transport (open access)

Analysis techniques for momentum transport

This report discusses the following topics on momentum analysis in tokamaks and stellarators: the momentum balance equation; deposition of torque by neutral beams; effects of toroidal rotation; and experimental observations. (LSP)
Date: August 1, 1991
Creator: Scott, S.D.
Object Type: Article
System: The UNT Digital Library
Analyzing geographic clustered response (open access)

Analyzing geographic clustered response

In the study of geographic disease clusters, an alternative to traditional methods based on rates is to analyze case locations on a transformed map in which population density is everywhere equal. Although the analyst's task is thereby simplified, the specification of the density equalizing map projection (DEMP) itself is not simple and continues to be the subject of considerable research. Here a new DEMP algorithm is described, which avoids some of the difficulties of earlier approaches. The new algorithm (a) avoids illegal overlapping of transformed polygons; (b) finds the unique solution that minimizes map distortion; (c) provides constant magnification over each map polygon; (d) defines a continuous transformation over the entire map domain; (e) defines an inverse transformation; (f) can accept optional constraints such as fixed boundaries; and (g) can use commercially supported minimization software. Work is continuing to improve computing efficiency and improve the algorithm. 21 refs., 15 figs., 2 tabs.
Date: August 1, 1991
Creator: Merrill, D.W.; Selvin, S. & Mohr, M.S.
Object Type: Article
System: The UNT Digital Library
Appliance Analysis :Residential Construction Demonstration Project Cycle 2. (open access)

Appliance Analysis :Residential Construction Demonstration Project Cycle 2.

The appliance use of RCDP-2 homes was analyzed to determine whether significant differences existed in houses that had efficient appliances (domestic hot water (DHW) and refrigerators) compared to those with appliances not considered efficient. Specific analyses addressed: (1) DHW and refrigerator appliance end uses; (2) whole house and space heat energy use; and, (3) interaction effects between appliance use and space heating energy use.
Date: August 1, 1991
Creator: Quaid, Maureen; Kunkle, Rick & Lagerberg, Brian
Object Type: Report
System: The UNT Digital Library
Application of a canine {sup 238}Pu dosimetry model to human bioassay data (open access)

Application of a canine {sup 238}Pu dosimetry model to human bioassay data

Associated with the use of 2{sup 238}Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to {sup 238}Pu, primarily by inhalation. In the event of human internal exposure, a means is needed for assessing the level of intake and calculating radiation doses. Several bioassay/dosimetry models have been developed for {sup 239}Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of {sup 238}Pu are significantly different from those for {sup 239}Pu. A canine model accounting for these differences has been applied in this work to urinary excretion data from seven humans occupationally exposed to low levels of an insoluble {sup 238}Pu compound. The modified model provides a good description of the urinary excretion kinetics observed in the exposed humans. The modified model was also used to provide estimates of the initial intakes of {sup 238}Pu for the seven individuals; these estimates ranged from 4.5 nCi (170 Bq) to 87 nCi (3200 Bq). Autopsy data on the amount and distribution of {sup 238}Pu retained in the organs may be used in the future to validate or refute both these estimates and the …
Date: August 1, 1991
Creator: Hickman, A. W. Jr.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Application of modern mathematical concepts to plasma confinement (open access)

Application of modern mathematical concepts to plasma confinement

Progress in three research areas has been achieved. (1) A new expression for the trapping probability for transitioning particles in asymmetric toroidal plasma confinement devices (e.g., stellarators and rippled tokamaks) has been derived. Comparison with numerical integrations shows that this new expression is more accurate than those of previous workers. (2) Simulations show that the dynamical enhancement of the turbulent diffusion coefficient over quasilinear observed in test particle simulations occurs also in selfconsistent plasma turbulence. (3) The simple method for calculating magnetic island widths discussed in the previous report has been published.
Date: August 1, 1991
Creator: Cary, J.R.
Object Type: Report
System: The UNT Digital Library
Application of Neural Networks to Flight Test Diagnostics (open access)

Application of Neural Networks to Flight Test Diagnostics

A system has been designed which can provide summary information about specific noisy electric pulses that are generated during flight testing. This is important from a telemetry viewpoint, since limited bandwidth often rules out transmitting all of the pulse data. The system is based on a neural network processing paradigm. The neural network serves as a mapping between pulse data inputs and pulse category outputs. Output categories correspond to presence or type of component failure. Extensive computer simulations have shown that the system can recognize qualitative pulse features which are useful for diagnostic purposes. A second version of the system, also using a neural network, was designed to perform data compression. In this case, an entire pulse is efficiently coded for transmission and the original signal is reconstructed upon receiving the coded transmission. Successful simulations for both systems have demonstrated feasibility and have led to a hardware development effort aimed at prototyping a fieldable system. Based on these results, it appears that the neural network approach may be applicable to other diagnostic and data analysis problems arising in component or system testing. 3 refs., 16 figs., 2 tabs.
Date: August 1, 1991
Creator: Wheeler, R.M. Jr. & Sheaffer, D.A.
Object Type: Report
System: The UNT Digital Library
Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor refueling (open access)

Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor refueling

This report contains three documents describing the progress made by the University of Illinois electromagnetic railgun program sponsored by the Office of Fusion Energy of the United States Department of Energy during the period from July 16, 1990 to August 16, 1991. The first document contains a brief summary of the tasks initiated, continued, or completed, the status of major tasks, and the research effort distribution, estimated and actual, during the period. The second document contains a description of the work performed on time resolved laser interferometric density measurement of the railgun plasma-arc armature. The third document is an account of research on the spectroscopic measurement of the electron density and temperature of the railgun plasma arc.
Date: August 1, 1991
Creator: Kim, K.
Object Type: Report
System: The UNT Digital Library
Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor refueling. Technical progress report, [July 16, 1990--August 16, 1991] (open access)

Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor refueling. Technical progress report, [July 16, 1990--August 16, 1991]

This report contains three documents describing the progress made by the University of Illinois electromagnetic railgun program sponsored by the Office of Fusion Energy of the United States Department of Energy during the period from July 16, 1990 to August 16, 1991. The first document contains a brief summary of the tasks initiated, continued, or completed, the status of major tasks, and the research effort distribution, estimated and actual, during the period. The second document contains a description of the work performed on time resolved laser interferometric density measurement of the railgun plasma-arc armature. The third document is an account of research on the spectroscopic measurement of the electron density and temperature of the railgun plasma arc.
Date: August 1, 1991
Creator: Kim, K.
Object Type: Report
System: The UNT Digital Library
Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media (open access)

Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of structural characteristics of the medium. The report further reviews and analyzes large-scale hydrogeologic spatial variability from aquifer data, unsaturated soil data, and fracture network data gathered from the literature. Finally, various modeling strategies toward large-scale flow simulations are assessed, including direct high-resolution simulation, and coarse-scale simulation based on auxiliary hydrodynamic models such as single equivalent continuum and dual-porosity continuum. The roles of anisotropy, fracturing, and broad-band spatial variability are emphasized. 252 refs.
Date: August 1, 1991
Creator: Ababou, R.
Object Type: Report
System: The UNT Digital Library
Archer County News (Archer City, Tex.), No. 31, Ed. 1 Thursday, August 1, 1991 (open access)

Archer County News (Archer City, Tex.), No. 31, Ed. 1 Thursday, August 1, 1991

Weekly newspaper from Archer City, Texas that includes local, state and national news along with advertising.
Date: August 1, 1991
Creator: Lobpries, F. Mike & Lobpries, Fran
Object Type: Newspaper
System: The Portal to Texas History