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Heavy-ion inertial fusion: initial survey of target gain versus ion-beam parameters

Description: Inertial-fusion targets have been designed for use with heavy-ion accelerators as drivers in fusion energy power plants. We have made an initial survey of target gain versus beam energy, power, focal radius, and ion range. This provides input for understanding the trade-offs among accelerator designs.
Date: October 26, 1981
Creator: Bangerter, R.O.; Mark, J.W.K. & Thiessen, A.R.
Partner: UNT Libraries Government Documents Department
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Atomic and electronic structure of metals and alloys: Clean surfaces and chemisorbed molecules

Description: The accomplishments of the work done under DOE sponsorship are summarized in the list of publications at the end of this narrative. Here we give a brief description of the nature and the significance of the accomplishments. The activity can be roughly subdivided into three parts: studies of surface alloys, studies of epitaxial ultra-thin films, and studies of electron band structure of metals. The list reflects the developments of particular areas of research and the phasing out of others as this was suggested by the interest in, and the success of, specific experimental projects.
Date: November 26, 1991
Partner: UNT Libraries Government Documents Department
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Thermal loading considerations for synchrotron radiation mirrors

Description: Grazing incidence mirrors used to focus synchrotron radiation beams through small distant apertures have severe optical requirements. The surface distortion due to heat loading of the first mirror in a bending magnet beam line is of particular concern when a large fraction of the incident beam is absorbed. In this paper we discuss mirror design considerations involved in minimizing the thermal/mechanical loading on vertically deflecting first surface mirrors required for SPEAR synchrotron radiation beam lines. Topics include selection of mirror material and cooling method, the choice of SiC for the substrate, optimization of the thickness, and the design of the mirror holder and cooling mechanism. Results obtained using two-dimensional, finite-element thermal/mechanical distortion analysis are presented for the case of a 6/sup 0/ grazing incidence SiC mirror absorbing up to 260 W at Beam Line VIII on the SPEAR ring. Test descriptions and results are given for the material used to thermally couple this SiC mirror to a water-cooled block. The interface material is limited to applications for which the equivalent normal heat load is less than 20 W/cm/sup 2/.
Date: March 26, 1986
Creator: Holdener, F. R.; Berglin, E. J.; Fuchs, B. A.; Humpal, H. H.; Karpenko, V. P.; Martin, R. W. et al.
Partner: UNT Libraries Government Documents Department
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Inference about population attributable risk from cross-sectional studies

Description: The population attributable risk (PAR) is defined as the fraction of all cases of a disease in a population due to exposure to a given risk factor. The data collected in cross-sectional surveys are used to test a formula of standard error of PAR from which a 95% confidence interval for PAR may be deduced.
Date: March 26, 1979
Creator: Fleiss, J.L.
Partner: UNT Libraries Government Documents Department
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Present and future nuclear power generation as a reflection of individual countries' resources and objectives

Description: The nuclear reactor industry has been in a state of decline for more than a decade in most of the world. The reasons are numerous and often unique to the energy situation of individual countries. Two commonly cited issues influence decisions relating to construction of reactors: costs and the need, or lack thereof, for additional generating capacity. Public concern has ''politicized'' the nuclear industry in many non-communist countries, causing a profound effect on the economics of the option. The nuclear installations and future plans are reviewed on a country-by-country basis for 36 countries in the light of the resources and objectives of each. Because oil and gas for power production throughout the world are being phased out as much as possible, coal-fired generation currently tends to be the chosen alternative to nuclear power production. Exceptions occur in many of the less developed countries that collectively have a very limited operating experience with nuclear reactors. The Chernobyl accident in the USSR alarmed the public; however, national strategies and plans to build reactors have not changed markedly in the interim. Assuming that the next decade of nuclear power generation is uneventful, additional electrical demand would cause the nuclear power industry to experience a rejuvenation in Europe as well as in the US. 80 refs., 3 figs., 22 tabs.
Date: June 26, 1987
Creator: Borg, I.Y.
Partner: UNT Libraries Government Documents Department
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Seismic safety in nuclear-waste disposal

Description: Seismic safety is one of the factors that must be considered in the disposal of nuclear waste in deep geologic media. This report reviews the data on damage to underground equipment and structures from earthquakes, the record of associated motions, and the conventional methods of seismic safety-analysis and engineering. Safety considerations may be divided into two classes: those during the operational life of a disposal facility, and those pertinent to the post-decommissioning life of the facility. Operational hazards may be mitigated by conventional construction practices and site selection criteria. Events that would materially affect the long-term integrity of a decommissioned facility appear to be highly unlikely and can be substantially avoided by conservative site selection and facility design. These events include substantial fault movement within the disposal facility and severe ground shaking in an earthquake epicentral region. Techniques need to be developed to address the question of long-term earthquake probability in relatively aseismic regions, and for discriminating between active and extinct faults in regions where earthquake activity does not result in surface ruptures.
Date: April 26, 1979
Creator: Carpenter, D.W. & Towse, D.
Partner: UNT Libraries Government Documents Department
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Modelling, measurement and construction of the stripline kickers for the Tevatron transverse dampers

Description: In this paper, we will describe the modelling, measurement and construction of the stripline kickers for the Tevatron transverse dampers. We will show that the odd/even impedances calculated using Poisson gave very good results when compared to the measured odd/even impedances of a stripline prototype. Using the prototype, we will show how we had adjusted the launch impedance so that the reflection coefficient s<sub>11</sub> < -35 dB between 0 to 100 MHz. We will also show the final design of the kickers and point out the deficiencies of this design.
Date: October 26, 1999
Creator: Tan., Cheng-Yang
Partner: UNT Libraries Government Documents Department
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Processes of community development and responses of ecosystems to climate change

Description: Our studies focus on attempting to understand the role of decomposer-primary producer linkages in successional dynamics. We are testing a series of hypotheses that relate changes in plant species composition during succession to changes in activity and structure of the soil microfloral and faunal community, dynamics of soil organic matter, and availability of soil nutrients. As these successional patterns are identified, they are being applied to understanding specific processes and mechanics involved in ecosystem development during recovery from moderate and severe disturbances. These findings are then being used in conjunction with simulation models to assess potential effects of climate change on ecosystems. Our research involves field studies in northwestern Colorado and southeastern Washington, laboratory studies, and simulation modeling. Ongoing projects include studies of response patterns of primary producer and soil microbial communities to nutrient additions (N, P, and sucrose), the function of mycorrhizal fungi in plant community development, and the dynamics of litter decomposition under semiarid conditions. New studies are being implemented to investigate the significance of nutrient transfers from VAM fungi to plants and plant-root exudate interactions, and to relate this to understanding their roles in succession.
Date: May 26, 1989
Creator: Redente, E.F.
Partner: UNT Libraries Government Documents Department
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Cryosorption vacuum pumping of hydrogen and helium mixtures

Description: Cryosorption vacuum pumps continue to be the principal type of pumping systems considered for power-producing fusion reactors. In this context, a compound-pump concept is generally employed in which the helium pump is placed behind the hydrogen pump so that hydrogen will not condense on and hence block the 4.2 K helium cryosorption surface. To obtain an optimal design for such a pump, the amount of hydrogen which can reach the helium panel has been determined. Catastrophic failure of a cryosorption pump was observed in previous work when a 95% hydrogen-5% helium mixture was tested. No such failure has occurred in our studies with 4, 10, and 20% hydrogen. However, significant changes in pumping speed have been noted when only 4% hydrogen is present. Both helium and hydrogen speeds are reduced to approximately one-half to one-third of the pure compound speed. Many of the qualitative aspects of the behavior of the pump for pure helium are also observed for the hydrogen-helium mixtures. Cyclic variation in pumping speed above a helium feed rate of approx. 6 x 10/sup -6/ torr-L/s.cm/sup 2/ is one such similarity; however, at the 4% hydrogen level, the period between instabilities is longer for the mixtures.
Date: October 26, 1981
Creator: Fisher, P. W.; Rogers, F. L. & Watson, J. S.
Partner: UNT Libraries Government Documents Department
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Prospects for inertial fusion as an energy source

Description: Progress in the Inertial Confinement Fusion (ICF) Program has been very rapid in the last few years. Target physics experiments with laboratory lasers and in underground nuclear tests have shown that the drive conditions necessary to achieve high gain can be achieved in the laboratory with a pulse-shaped driver of about 10 MJ. Requirements and designs for a Laboratory Microfusion Facility (LMF) have been formulated. Research on driver technology necessary for an ICF reactor is making progress. Prospects for ICF as an energy source are very promising. 11 refs., 5 figs.
Date: June 26, 1989
Creator: Hogan, W.J.
Partner: UNT Libraries Government Documents Department
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Technical memo on PbF/sub 2/ as a Cherenkov radiator for EM calorimetry

Description: It is apparent that the ever increasing rates and radiation levels found in high-energy physics are excluding more and more instrumental techniques. Those techniques that are remaining are often pushed to their theoretical limits. This situation reaches an extreme at the proposed luminosity of the SSC. Also, it is fair to say that at the SSC, after the accelerator itself, calorimetry will be the next most important physics tool. Therefore, we should be ever alert to new calorimetry techniques which may operate in this demanding environment. The material lead fluoride, PbF/sub 2/, has a real potential of yielding a very compact, high-resolution electromagnetic calorimeter that is both fast and radiation hard. PbF/sub 2/ is not a scintillator but a Cherenkov radiator like lead glass, but with a radiation length even harder shorter than of BGO. This memo discusses this property as well as comparison PbF/sub 2/ to other scintillating materials. 2 refs., 14 figs., 1 tab.
Date: June 26, 1989
Creator: Anderson, D. F.
Partner: UNT Libraries Government Documents Department
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Impact of several reactor features on TF coil design for TPSS

Description: A significant driver of machine size in previous designs was the amount of nuclear shielding placed between the blanket and the toroidal field (TF) coils to minimize the radiation heating and damage in these critical components. Of course the total amount of shielding is not arbitrary; it certainly must adequately suppress radiation outside the plant. However, if all of this shielding were contained inside the TF coils, several parameters (coil size and weight, maximum field at the windings, stored energy, etc.) would become inordinately large. Reducing the amount of shielding inside the TF coils and allowing the radiation load to climb to less ''conventional'' levels could pay big benefits in reducing the machine size, so long as the damage and heat load remain tolerable. Recent studies indicate that superconducting windings in TF coils can accept much higher heat loads than have been previously considered and simultaneously can be designed with higher than conventional current densities. The purpose of the present exercise is to probe the limits of acceptable radiation levels in relation to winding pack current densities in the TF coils for reactor relevant designs.
Date: March 26, 1986
Creator: Miller, J. R. & Bulmer, R. H.
Partner: UNT Libraries Government Documents Department
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WAS Release 4 - Usability Test Results

Description: This report discusses the usability test results for the Web-at-Risk project at the University of North Texas (UNT). Usability testing of the Web Archiving Service (WAS) Release 4 was conducted on May 29, 2007. Eight of the project's curators participated in test sessions, which generally were completed in 45-60 minutes. Two testing teams, each consisting of a facilitator and two observers were involved in testing.
Date: June 26, 2007
Creator: Murray, Kathleen R.
Partner: UNT Libraries
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Probing electroweak symmetry breaking at multi-TeV colliders

Description: Low energy theorems are derived for scattering of longitudinally polarized W and Z's, providing the basis for an estimate of the observable signal if electroweak symmetry breaking is due to new physics at the TeV scale. A pp collider with L, {radical}s {equals} 40 TeV, 10{sup 33}cm. {sup {minus}2}s{sup {minus}1} is just sufficient to observe the signal while pp colliders with 40, 10{sup 32} or 20, 10{sup 33} are not. A collider that is sensitive to the TeV-scale signal provides valuable information about symmetry breaking whether the masses of the associated new particles are below, within, or above the 1-2 TeV region. 6 refs., 6 figs., 2 tabs.
Date: March 26, 1987
Creator: Chanowitz, Michael S.
Partner: UNT Libraries Government Documents Department
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Geothermal district heating system feasibility analysis, Thermopolis, Wyoming

Description: The purpose of this study is to determine the technical and economic feasibility of constructing and operating a district heating system to serve the residential, commercial, and public sectors in Thermopolis. The project geothermal resource assessment, based on reviews of existing information and data, indicated that substantial hot water resources likely exist in the Rose Dome region 10 miles northeast of Thermopolis, and with quantities capable of supporting the proposed geothermal uses. Preliminary engineering designs were developed to serve the space heating and hot water heating demands for buildings in the Thermopolis-East Thermopolis town service area. The heating district design is based on indirect geothermal heat supply and includes production wells, transmission lines, heat exchanger units, and the closed loop distribution and collection system necessary to serve the individual customers. Three options are presented for disposal of the cooled waters-reinjection, river disposal, and agricultural reuse. The preliminary engineering effort indicates the proposed system is technically feasible. The design is sized to serve 1545 residences, 190 businesses, and 24 public buildings. The peak design meets a demand of 128.2 million Btu at production rates of 6400 gpm.
Date: April 26, 1982
Creator: Goering, S.W.; Garing, K.L.; Coury, G. & Mickley, M.C.
Partner: UNT Libraries Government Documents Department
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Integrated test vehicle program plan: revision C

Description: This edition dated August 26, 1977, is Revision C of the Integrated Test Vehicle, Program Plan, Phase II - Deliverable Item 2-7-1. The original edition was issued on May 27, 1977. Corrections were made and issued as Proposed Modifications for Integrated Test Vehicle, Program Plan, dated July 8, 1977. For the purpose of documenting changes, the July 8, 1977, version is caled Revision A. The edition dated August 5, 1977, is called Revision B. Each paragraph in this edition is marked to indicate technical changes from previous editions.
Date: August 26, 1977
Partner: UNT Libraries Government Documents Department
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Analysis of a flow metering device for low-quality steam-water flows. Final report

Description: The goal of this project is to investigate the potential of the meter configuration consisting of a sharp-edged contraction section followed by an extended length of constant area duct and finally a diffuser section for pressure recovery. This and two other configurations were tested. These configurations and the reasons underlying their selection are described and discussed. It is concluded that Murdock's correlation for steam/water flow through orifices and sudden contraction sections at low qualities is invalid and the metering scheme based on it is inoperative. (MHR)
Date: June 26, 1979
Creator: Crowe, C.T.
Partner: UNT Libraries Government Documents Department
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Microprocessor control and data acquisition at the LLNL 100-MeV accelerator

Description: A distributed microprocessor control and data acquisition network has been designed for implementation on the Lawrence Livermore National Laboratory 100 MeV electron/positron accelerator (LINAC). The system has been designed to be as transparent to the user as possible by stressing responsiveness, reliability, and relevance of data presented to the user. Implementation of the network will take place in modular fashion in three stages, so as to minimize disruption of normal operations. The first elements to be installed will be the beam transport system controls, beam set-up time. Beam diagnostic equipment is now being position monitors, and accelerator operating status monitors. These units will reduce beam set-up time. Beam diagnostic equipment is now being designed that will be used in a second stage implementation. This stage will concentrate on determining beam parameters and allowing the user to optimize the beam for a given parameter. The final stage will be to install experimenter data acquisition equipment. The equipment will augment the presently existing data acquisition system. The completed network will allow a more efficient operation of the LINAC, resulting in reduced experiment costs, and more controllable beam parameters, both of which are major concerns of experimenters.
Date: May 26, 1981
Creator: Mendonca, M.L.
Partner: UNT Libraries Government Documents Department
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