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Theoretical high energy physics research at the University of Chicago, Task A
This report discusses research conducted at the University of Chicago in theoretical high energy physics. Some of the areas included in this report are: cp violation and cabibbo-kobayashi-maskawa matrix; radiative corrections and electroweak observables; heavy quark symmetry; heavy meson spectroscopy; hadronic string theory; composite models of quarks and leptons; and pedagogical effects. (LSP)
Date:
April 1, 1992
Creator:
Rosner, J.L.; Martinec, E.J. & Sachs, R.G.
Object Type:
Report
System:
The UNT Digital Library
Module process optimization and device efficiency improvement for stable, low-cost, large-area, cadmium telluride-based photovoltaic module production
This report describes work under a three-year phased subcontract to develop CdS/CdTe devices and modules and to further improve the technology base at Photon Energy, Inc. (PEI) to better address the commercialization issues and objectives of the PEI and the US Department of Energy. During this reporting period we (1) achieved efficiencies of 12.7% on small area devices, (2) achieved 1-ft{sup 2} modules with over 8% aperture-area efficiency (and active area efficiencies up to {approximately}10%), (3) tested 4-ft{sup 2} modules at NREL at 23.1 (21.3) watts, normalized (6.3% efficiency), and (4) found no inherent stability problems with CdTe technology during life testing, at both NREL and PEI. 7 refs.
Date:
April 1, 1992
Creator:
Albright, S. P.; Ackerman, B.; Chamberlin, R. R. & Jordan, J. F.
Object Type:
Report
System:
The UNT Digital Library
Application Experience and Field Performance of Silvered Polymer Reflectors
The solar-weighted hemispheric reflectance of unweathered silvered acrylic mirrors exceeds 92%, and specular reflectance into a 4- milliradian, full-cone acceptance angle is greater than 90%. Comparison of outdoor and accelerated tests suggests that the protected silver can resist corrosion for the five-year life that is the current goal. An installation of parabolic troughs has been cleaned monthly for two years, and reflectance is regularly returned to within a few percent of the initial reflectance values. In the presence of moisture, the silver/acrylic bond can delaminate to form a maze of tunnels and destroy specular reflectance. Proper edge preparation and protection delay the initiation of tunnels. 6 refs.
Date:
April 1, 1991
Creator:
Schissel, P.; Jorgensen, G. & Pitts, R.
Object Type:
Article
System:
The UNT Digital Library
Marion Industrial Substation Project : Environmental Assessment.
Consumers Power, Inc. (CPI), proposes to construct a new distribution substation under the existing Bonneville Power Administration (BPA) Albay-Lebanon transmission line near the city of Albany in Linn County, Oregon. BPA is proposing to grant a new Point of Delivery to CPI at this substation. The purpose of the project is to serve the developing industrial needs in the Marion Industrial Park and on the 550 acres of nearby land within CPI's service area that are zoned for residential use. CPI prepared, and the Rural Electrification Administration (REA) has approved a Borrower's Environmental Report (BER) which addresses this action along with several other proposed projects in the CPI service area. Portions of this BER are summarized in this brief EA. BPA is preparing its own EA since Department of Energy National Environmental Policy Act (NEPA) guidelines require additional environmental concerns to be addressed than are required by REA's NEPA guidelines.
Date:
April 1, 1992
Creator:
United States. Bonneville Power Administration.
Object Type:
Report
System:
The UNT Digital Library
Automatic Differentiation Applied to Unsaturated Flow - ADOL-C Case Study
We have experimented with many variants of the code dual.c for two-dimensional unsaturated flow in a porous medium. The goal has been to speed up the evaluation of derivatives required for a Newton iteration. We have primarily investigated the use of ADOL-C, a C++ tool for automatic differentiation and have come to the following conclusions: three colors suffice for computing the nonlinear portion of the Jacobian. That speeds up the Jacobian evaluation in the original code by a factor of two. The use of ADOL-C for automatic differentiation does not speed up the code. The best result we have achieved for automatic differentiation takes twice as long as the original centered difference approximation. The derivative values computed by ADOL-C are more accurate than the centered difference approximations. We can realize big savings in the linear equation solver.
Date:
April 1, 1992
Creator:
Corliss, G.; Griewank, A.; Wright, S. & Robey, T.
Object Type:
Report
System:
The UNT Digital Library
Electronic states in systems of reduced dimensionality
This report briefly discusses the following research: magnetically modulated systems, inelastic magnetotunneling, ballistic transport review, screening in reduced dimensions, raman and electron energy loss spectroscopy; and ballistic quantum interference effects. (LSP).
Date:
April 15, 1992
Creator:
Ulloa, S.E.
Object Type:
Report
System:
The UNT Digital Library
A method of generating k-fluorescence x-rays
For radiation protection purposes of k-fluorescence x-rays are useful for determining the energy response of instruments and dosimeters because they are nearly monoenergetic. the International Organization for Standardization (ISO) has specified the x-ray energies and radiator and filter materials for the production of such x-rays. There are two techniques useful for producing x-rays at approximately 17 and 59 keV; these techniques produce a situation that approximates the x-ray and gamma ray emissions of plutonium and americium isotopes. The Department of Energy Laboratory Accreditation Program (DOELAP) performance-testing standard for personnel dosimeters incorporates these k-fluorescence techniques. The Radiation Calibrations Facility at the Pacific Northwest Laboratory (PNL) has produced k-fluorescence x-rays for many years. Over the years, we have worked at improving this type of radiation for our performance-testing programs. This report describes the present geometry for the generation of k-fluorescence x-rays, a geometry proven more efficient in our facility. The exposure rate has increased and the beam uniformity has improved. Details of the geometry will be discussed.
Date:
April 1, 1992
Creator:
Fox, R.A.; Hooker, C.D. & McDonald, J.C.
Object Type:
Article
System:
The UNT Digital Library
Computer simulation of shading and blocking: Discussion of accuracy and recommendations
A field of heliostats suffers losses caused by shading and blocking by neighboring heliostats. The complex geometry of multiple shading and blocking events suggests that a processing code is needed to update the boundary vector for each shading or blocking event. A new version, RSABS, (programmer's manual included) simulates the split-rectangular heliostat. Researchers concluded that the dominant error for the given heliostat geometry is caused by the departure from planarity of the neighboring heliostats. It is recommended that a version of the heliostat simulation be modified to include losses due to nonreflective structural margins, if they occur. Heliostat neighbors should be given true guidance rather than assumed to be parallel, and the resulting nonidentical quadrilateral images should be processed, as in HELIOS, by ignoring overlapping events, rare in optimized fields.
Date:
April 1, 1992
Creator:
Lipps, F.W. (Houston Univ., TX (United States))
Object Type:
Report
System:
The UNT Digital Library
Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells
This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by …
Date:
April 1, 1992
Creator:
Chu, T.L. (University of South Florida, Tampa, FL (United States))
Object Type:
Report
System:
The UNT Digital Library
Alternative positron-target design for electron-positron colliders
Current electron-positron linear colliders are limited in luminosity by the number of positrons which can be generated from targets presently used. This paper examines the possibility of using an alternate wire-target geometry for the production of positrons via an electron-induced electromagnetic cascade shower. 39 refs., 38 figs., 5 tabs.
Date:
April 1, 1991
Creator:
Donahue, R. J. & Nelson, W. R.
Object Type:
Report
System:
The UNT Digital Library
National Synchrotron Light Source annual report 1991
This report contains abstracts from research conducted at the national synchrotron light source. (LSP)
Date:
April 1, 1992
Creator:
Hulbert, S.L. & Lazarz, N.N. (eds.)
Object Type:
Report
System:
The UNT Digital Library
Grain boundary weak links in high- Tc superconductors
The transport critical current density (Jc) for high-{Tc} thin films, bicrystals, and bulk ceramics is shown to be determined by magnetic field penetration into the grain boundaries. The gross grain orientations may not in all cases be an important factor in determining this penetration. The parameter ({lambda}{sub G}/{lambda}{sub J}){sup 2} can characterize the strength of the grain boundary coupling, which depends mainly on the crystal coherence and connectivity at the boundary area.
Date:
April 1, 1992
Creator:
Shi, D.; Sengupta, S.; Goretta, K.C.; Salem-Sugui, S. Jr. (Argonne National Lab., IL (United States)); Smith, M. & Lwin, Y.N. (Western Illinois Univ., Macomb, IL (United States). Dept. of Physics)
Object Type:
Article
System:
The UNT Digital Library
Materials science in solar cell development
None
Date:
April 1, 1992
Creator:
Park, J. H.
Object Type:
Article
System:
The UNT Digital Library
Experimental particle physics at the University of Pittsburgh
During the past year Task A completed the HELIOS single and pair electron analyses and found no anomalous production or multiplicity dependence. The HELIOS electron-muon pair analysis continued in its search for lepton physics beyond the expected charm yields. Data taking began at the CMD2 detector at Novosibirsk. Measurements of the U. V. reflectivity and photomultiplier tests for the first Cerenkov counter to be used in the E865 experiment at BNL were carried out, along with the development of a general ray-tracing code. The design of the Cerenkov counter for E865 along with development of light mirror fabrication techniques were a major part of the Task A program. The principal efforts of Task B, the Fermilab program, have been the completion of the analysis of the 1987--1988 data with resulting publications, completion of the 1990--1991 data run, and the beginning of the analysis of the 1990--1991 data. In addition, the Task B group is taking a leadership role in developing a proposal to Fermilab for the upgrade of the CDF silicon vertex detector in preparation for the 1995 data run. This proposal is to be presented to the laboratory management in time for the fall Fermilab Program Advisory Committee meeting. …
Date:
April 1, 1992
Creator:
Engels Jr., E.; Perera, U.; Shepard, P. F. & Thompson, J. A.
Object Type:
Report
System:
The UNT Digital Library
Discrete fracture simulations of the hydrogeology at Koongarra, Northern Territory, Australia
The US Department of Energy is studying the Alligator Rivers Natural Analogue Project site at Koongarra, Northern Territory, Australia to investigate and simulate radionuclide migration in fractured rocks. Discrete fracture simulations were conducted within a cubic volume (180-m edge length) of fractured Cahill Formation schist oriented with one major axis parallel to the trend of the Koongarra Fault. Five hundred fractures are simulated within this domain. The fractures have a mean orientation parallel to the idealized plane of the Koongarra Fault dipping 55{degrees} SE. Simple flow modeling of this fracture network was conducted by assigning constant head boundaries to upgradient and downgradient vertical faces of the cube, which trend parallel to the fault. No-flow boundaries were assigned to all other faces. The fracture network allows hydraulic communication across the block, in spite of relatively low fracture density across the block.
Date:
April 1, 1992
Creator:
Smoot, J.L.
Object Type:
Article
System:
The UNT Digital Library
Environmentally sound irrigated agriculture in the arid west: New challenges for water resources planners and environmental scientists
This is an exciting time for water resources planners and environmental scientists in the State and Federal Agencies in California. The growing environmental awareness of the public has raised their interest in the manner by which water is managed and allocated. Current and future impending water shortages are challenging engineers and planners to make sound policy and system operations decisions to maximize the utility of scarce water resources while ensuring that the environment within which we live is adequately protected to the satisfaction of an informed public. New and innovative decision support systems are needed to meet these challenges that are flexible, comprehensible and accurate and which allow the public a more visible role in the planning process. These changes may help to bring the agricultural and environmental communities closer together in finding solutions to water resources problems and wrest policy making for water resources management out of the hands of lawyers and the courts and restore it to those whose livelihoods are affected by the intentions of these policies. 4 refs.
Date:
April 1, 1991
Creator:
Quinn, N.W.T.
Object Type:
Article
System:
The UNT Digital Library
Outline of a proposal for a new neutron source: The pulsed neutron research facility
Accelerator-based, pulsed spallation neutron sources have been performing neutron scattering research for about fifteen years. During this time beam intensities have increased by a factor of 100 and more than 50 spectrometers are now operating on four major sources worldwide. The pulsed sources have proven to be highly effective and complementary to reactor-based sources in that there are important scientific areas for which each type of source has unique capabilities. We describe a proposal for a new pulsed neutron facility based on a Fixed Field Alternating Gradient synchrotron. The specifications for this new machine, which are now only being formulated, are for an accelerator that will produce (100 {divided by} 200) {mu}A of time-averaged proton current at (500 {divided by} 1000) MeV, in short pulses at 30 Hz. Appropriate target and moderator systems and an array of scattering instruments will be provided to make the facility a full-blown research installation. The neutron source, named the Pulsed Neutron Research Facility (PNRF), will be as powerful as any pulsed source now operating in the world and will also act as a test bed for the Fixed Field Alternating Gradient Synchrotron concept as a basis for more powerful sources in the future. The …
Date:
April 1, 1992
Creator:
Brown, B. S.; Carpenter, J. M. & Kustom, R. L.
Object Type:
Article
System:
The UNT Digital Library
Design and calibration of a test facility for MLI thermal performance measurements below 80K. [Multilayer insulation (MLI)]
The design geometry of the SSC dipole cryostat includes active thermal radiation shields operating at 80K and 20K respectively. Extensive measurements conducted in a Heat Leak Test Facility (HLTF) have been used to evaluate the thermal performance of candidate multilayer insulation (MLI) systems for the 80K thermal shield, with the present system design based upon those measurement results. With the 80K MLI geometry established, efforts have focused on measuring the performance of MLI systems near 20K. A redesign of the HLTF has produced a measurement facility capable of conducting measurements with the warm boundary fixed at 80K and the cold boundary variable from 10K to 50K. Removing the 80K shield permits measurements with a warm boundary at 300K. The 80K boundary consists of a copper shield thermally anchored to a liquid nitrogen reservoir. The cold boundary consists of a copper anchor plate whose temperature is varied through boil-off gas from a 500 liter helium supply dewar. A transfer line heat exchanger supplies the boil-off gas to the anchor plate at a constant and controlled rate. The gas, which serves as cooling gas, is routed through a copper cooling tube soldered into the anchor plate. Varying the cooling gas flow rate …
Date:
April 1, 1992
Creator:
Boroski, W.; Kunzelman, R.; Ruschman, M. & Schoo, C.
Object Type:
Article
System:
The UNT Digital Library
NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts
During this period, we focused our attention in analyzing the magnetic nature of the extensively used trimetallic catalyst system Cu-Co-Cr for the production of higher alcohols. We believe that there could be some correspondence between the catalytic and magnetic behaviors of the transition metal catalyst systems. Both the morphology and metallic charge distribution of the particles are know to govern the catalytic as well as the magnetic properties of the system. Based on this concept, we have extensively examined the Cu/Co system varying Cu/Co ratio from 0.2--4.0. Spectroscopic results are outlined herein. (VC)
Date:
April 15, 1992
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts
The primary concern of the study during this period has been to examine the origin and basis of the several nonconforming NMR lines reported in our earlier study. Previous studies by earlier investigators indicate that (a) the product distribution in the conversion of synthesis gas to liquid fuels is dependant on the copper/cobalt ratio and (b) that the catalytic results reported by different groups of investigators using the IFP prescription (4) are widely divergent. These observations prompted us to make a critical examination of the effect of metal ratio and the method of preparation on the magnetic character of catalysts.
Date:
April 4, 1991
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Collisional and chaotic transport of energetic particles in toroidal plasma
We have made progress in three general areas of confinement plasma physics is proposed. We developed an accurate theory for the trapping/detrapping process in tokamaks with ripple and stellarators. We determined the alpha particle distribution in the situation where both collisions and collisionless chaotic (ripple) transport are present.
Date:
April 1992
Creator:
Cary, J.R. & Shasharina, S.G.
Object Type:
Report
System:
The UNT Digital Library
GenoGraphics for OpenWindows trademark
GenoGraphics is a generic utility for constructing and querying one-dimensional linear plots. The outgrowth of a request from Dr. Cassandra Smith for a tool to facilitate her genome mapping research. GenoGraphics development has benefited from a continued collaboration with her. Written in Sun Microsystem's OpenWindows environment and the BTOL toolkit developed at Argonne National Laboratory. GenoGraphics provides an interactive, intuitive, graphical interface. Its features include: viewing multiple maps simultaneously, zooming, and querying by mouse clicking. By expediting plot generation, GenoGraphics gives the scientist more time to analyze data and a novel means for deducing conclusions.
Date:
April 1, 1992
Creator:
Hagstrom, R.; Overbeek, R.; Price, M.; Zawada, D. (Argonne National Lab., IL (United States)); Michaels, G.S.; Taylor, R. (National Insts. of Health, Bethesda, MD (United States). Div. of Computer Research and Technology) et al.
Object Type:
Report
System:
The UNT Digital Library
Atomic physics in strong fields
This report discusses: Microwave Driven Multiphoton Excitation Dynamics in Rydberg Atoms; Nonadiabatic Geometric Phases of Multiphoton Transitions in Dissipative Systems and Spin-j Systems; and Nonperturbative Treatments of Atomic and Molecular Processes in Intense Laser Fields.
Date:
April 1, 1992
Creator:
Chu, Shih-I.
Object Type:
Report
System:
The UNT Digital Library
Energy Division annual progress report for period ending September 30, 1991
The Energy Division is one of 17 research divisions at Oak Ridge Laboratory. Its goals and accomplishments are described in this annual progress report for FY 1991. The division's total expenditures in FY 1991 were $39.1 million. The work is supported by the US Department of Energy, US Department of Defense, many other federal agencies, and some private organizations. Disciplines of the 124 technical staff members include engineering, social sciences, physical and life sciences, and mathematics and statistics. The Energy Division's programmatic activities focus on three major areas: (1) analysis and assessment, (2) energy conservation technologies, and (3) military transportation systems. Analysis and assessment activities cover energy and resource analysis, the preparation of environmental assessments and impact statements, research on waste management, analysis of emergency preparedness for natural and technological disasters, analysis of the energy and environmental needs of developing countries, technology transfer, and analysis of civilian transportation. Energy conservation technologies include electric power systems, building equipment (thermally activated heat pumps, advanced refrigeration systems, novel cycles), building envelopes (walls, foundations, roofs, attics, and materials), and technical issues for improving energy efficiency in existing buildings. Military transportation systems concentrate on research for sponsors within the US military on improving the efficiency …
Date:
April 1, 1992
Creator:
Stone, J.N. (ed.)
Object Type:
Report
System:
The UNT Digital Library