Using the Tritium Plasma Experiment to evaluate ITER PFC safety. [Plasma-Facing Components] (open access)

Using the Tritium Plasma Experiment to evaluate ITER PFC safety. [Plasma-Facing Components]

The Tritium Plasma Experiment was assembled at Sandia National Laboratories, Livermore to investigate interactions between dense plasmas at low energies and plasma-facing component materials. This apparatus has the unique capability of replicating plasma conditions in a tokamak divertor with particle flux densities of 2 [times] 10[sup 19] ions/cm[sup 2] [center dot] s and a plasma temperature of about 15 eV using a plasma that includes tritium. With the closure of the Tritium Research Laboratory at Livermore, the experiment was moved to the Tritium Systems Test Assembly facility at Los Alamos National Laboratory. An experimental program has been initiated there using the Tritium Plasma Experiment to examine safety issues related to tritium in plasma-facing components, particularly the ITER divertor. Those issues include tritium retention and release characteristics, tritium permeation rates and transient times to coolant streams, surface modification and erosion by the plasma, the effects of thermal loads and cycling, and particulate production. A considerable lack of data exists in these areas for many of the materials, especially beryllium, being considered for use in ITER. Not only will basic material behavior with respect to safety issues in the divertor environment be examined, but innovative techniques for optimizing performance with respect to …
Date: January 1, 1993
Creator: Longhurst, G. R.; Anderl, R. A. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Bartlit, J. R. (Los Alamos National Lab., NM (United States)); Causey, R. A. (Sandia National Labs., Livermore, CA (United States)) & Haines, J. R. (MDC Aerospace, St. Louis, MO (United States))
Object Type: Article
System: The UNT Digital Library
Effect of deposits on corrosion of materials exposed in the Coal-Fired Flow Facility (open access)

Effect of deposits on corrosion of materials exposed in the Coal-Fired Flow Facility

Candidate heat exchanger materials tested in the Low Mass Flow train at the Coal-Fired Flow Facility (CFFF) at Tullahoma, TN. were analyzed to evaluate their corrosion performance. Tube specimens obtained at each foot of the 14-ft-long Unbend tubes were analyzed for corrosion-scale morphologies, scale thicknesses, and internal penetration depths. Results developed on 1500- and 2000- h exposed specimens were correlated with exposure temperature. In addition, deposit materials collected at several locations in the CFFF were analyzed in detail to characterize the chemical and physical properties of the deposits and their influence on corrosion performance of tube materials.
Date: May 1, 1993
Creator: Natesan, K.
Object Type: Article
System: The UNT Digital Library
Indexes of the proceedings for the nine symposia (international) on detonation, 1951--89 (open access)

Indexes of the proceedings for the nine symposia (international) on detonation, 1951--89

The Proceedings of the nine Detonation Symposia have become the major archival source of information of international research in explosive phenomenology, theory, experimental techniques, numerical modeling, and high-rate reaction chemistry. In many cases, they contain the original reference or the only reference to major progress in the field. For some papers, the information is more complete than the complementary article appearing in a formal journal, yet for others, authors elected to publish only an abstract in the Proceedings. For the large majority of papers, the Symposia Proceedings provide the only published reference to a body of work. This report indexes the nine existing Proceedings of the Detonation Symposia by paper titles, topic phrases, authors, and first appearance of acronyms and code names.
Date: January 1, 1993
Creator: Crane, S. L.; Deal, W. E.; Ramsay, J. B.; Roach, A. M. & Takala, B. E.
Object Type: Article
System: The UNT Digital Library
Search for the top quark from (e,[mu]) and (e,e) events in the D0 detector in p[bar p] collisions at [radical]s = 1. 8 TeV (open access)

Search for the top quark from (e,[mu]) and (e,e) events in the D0 detector in p[bar p] collisions at [radical]s = 1. 8 TeV

We present results from searches for top quark production in p[bar p] collisions at the Tevatron collider based on an integrated luminosity of 7.5 pb[sup [minus]1] obtained during the 1992--1993 ran. The present results are confined to decay modes where both the top and anti-top quarks in the event decay semi-leptonically to the ee and e[mu] channels. A lower limit of 103 (99) GeV/c[sup 2] is obtained at 95% confidence level for the top quark mass from the absence of events consistent with standard model top quark decays with background subtraction (no background subtraction). We do however observe one event in the e[mu] channel which cannot be explained by the known backgrounds. While we make no claim that this event is due to top quark decay, it is not inconsistent with a top quark mass in the range 130--170 GeV/c[sup 2]
Date: June 3, 1993
Creator: Raja, R.
Object Type: Article
System: The UNT Digital Library
A digital feedback system for orbit stabilization (open access)

A digital feedback system for orbit stabilization

The authors are reporting on the design and preliminary results of a prototype digital feedback system for the storage rings at the NSLS. The system will use a nonlinear eigenvector decomposition algorithm. It will have a wide dynamic range and will be able to correct noise in the orbit over a bandwidth in excess of 60 Hz. A Motorola-167 CPU board is used to sample the PUE's at a minimum rate of 200 Hz and an HP-742rt board is used to read the sampled signals and to generate a correction signal for the orbit correctors.
Date: January 1, 1993
Creator: Friedman, A.; Bozoki, E.; Singh, O. & Smith, J.
Object Type: Article
System: The UNT Digital Library
Modeling and measurement of the ALS U5 undulator end magnetic structures (open access)

Modeling and measurement of the ALS U5 undulator end magnetic structures

A brief summary of the activities of the traveler, information derived, and impressions gained while participating in the Japanese Science and Technology Agency's Forum for Multi-Disciplinary Research is given. A visit to the construction site of SPring 8, the new Japanese synchrotron radiation facility, also is described.
Date: May 1, 1993
Creator: Humphries, D.; Halbach, K.; Hoyer, E.; Kincaid, B.; Marks, S. & Schlueter, R.
Object Type: Article
System: The UNT Digital Library
Consolidation of geologic studies of geopressured-geothermal resources in Texas: Barrier-bar tidal-channel reservoir facies architecture, Jackson Group, Prado Field, South Texas (open access)

Consolidation of geologic studies of geopressured-geothermal resources in Texas: Barrier-bar tidal-channel reservoir facies architecture, Jackson Group, Prado Field, South Texas

Sandstone reservoirs in the Jackson barrier/strandplain play are characterized by low recovery efficiencies and thus contain a large hydrocarbon resource target potentially amenable to advanced recovery techniques. Prado field, Jim Hogg County, South Texas, has produced over 23 million bbl of oil and over 32 million mcf gas from combination structural-stratigraphic traps in the Eocene lower Jackson Group. Hydrocarbon entrapment at Prado field is a result of anticlinal nosing by differential compaction and updip pinch-out of barrier bar sandstone. Relative base-level lowering resulted in forced regression that established lower Jackson shoreline sandstones in a relatively distal location in central Jim Hogg County. Reservoir sand bodies at Prado field comprise complex assemblages of barrier-bar, tidal-inlet fill, back-barrier bar, and shoreface environments. Subsequent progradation built the barrier-bar system seaward 1 to 2 mi. With the barrier-bar system, favorable targets for hydrocarbon reexploration are concentrated in tidal-inlet facies because they possess the greatest degree of depositional heterogeneity.
Date: September 1, 1993
Creator: Seni, S. J. & Choh, S. J.
Object Type: Report
System: The UNT Digital Library
Adsorption of water vapor on reservoir rocks (open access)

Adsorption of water vapor on reservoir rocks

Progress is reported on: adsorption of water vapor on reservoir rocks; theoretical investigation of adsorption; estimation of adsorption parameters from transient experiments; transient adsorption experiment -- salinity and noncondensible gas effects; the physics of injection of water into, transport and storage of fluids within, and production of vapor from geothermal reservoirs; injection optimization at the Geysers Geothermal Field; a model to test multiwell data interpretation for heterogeneous reservoirs; earth tide effects on downhole pressure measurements; and a finite-difference model for free surface gravity drainage well test analysis.
Date: July 1, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Radiation effects on optoelectronic analog link for particle detectors (open access)

Radiation effects on optoelectronic analog link for particle detectors

The successful operation of an optoelectronic analog link for transfer of particle detector signals in high radiation area requires a detailed radiation damage study. We present at this conference the study of Ti: LiNbO[sub 3] optical modulators with gamma-rays and neutrons.
Date: May 1, 1993
Creator: Tsang, T.
Object Type: Article
System: The UNT Digital Library
Evolution of hadron beams under intrabeam scattering (open access)

Evolution of hadron beams under intrabeam scattering

Based on assumptions applicable to many circular accelerators, we simplify into analytical form the growth rates of a hadron beam under Coulomb intrabeam scattering (IBS). Because of the dispersion that correlates the horizontal closed orbit to the momentum, the scaling behavior of the growth rates are drastically different at energies low and high compared with the transition energy. At high energies the rates are approximately independent of the energy. Asymptotically, the horizontal and longitudinal beam amplitudes are linearly related by the average dispersion. At low energies, the beam evolves such that the velocity distribution in the rest frame becomes isotropic in all the directions.
Date: January 1, 1993
Creator: Wei, Jie.
Object Type: Article
System: The UNT Digital Library
Design of a Lambertson injection magnet for the RHIC machine (open access)

Design of a Lambertson injection magnet for the RHIC machine

A Lambertson magnet has been designed to serve as an injector into the Relativistic Heavy Ion Collider (RHIC) under construction at Brookhaven National Laboratory. The design is predicted to achieve field uniformity of DB/B < 6 [times]10[sup [minus]4] at B[sub o] = 9.5 KG transverse to the beam direction over the width of the beam path and stray fields in RHIC's circulating beam pipe of less than 0.2 Gauss. In addition, the magnet is ultra-high vacuum compatible in that only the insides of the beam tubes are exposed to the vacuum and the entire assembly is bakeable in situ to 300[degrees]C.
Date: January 1, 1993
Creator: Rodger, E.; Tsoupas, N.; Claus, J. & Foelsche, H. W.
Object Type: Article
System: The UNT Digital Library
Development of a methodology for conducting an integrated HRA/PRA -- (open access)

Development of a methodology for conducting an integrated HRA/PRA --

During Low Power and Shutdown (LP S) conditions in a nuclear power plant (i.e., when the reactor is subcritical or at less than 10--15% power), human interactions with the plant's systems will be more frequent and more direct. Control is typically not mediated by automation, and there are fewer protective systems available. Therefore, an assessment of LP S related risk should include a greater emphasis on human reliability than such an assessment made for power operation conditions. In order to properly account for the increase in human interaction and thus be able to perform a probabilistic risk assessment (PRA) applicable to operations during LP S, it is important that a comprehensive human reliability assessment (HRA) methodology be developed and integrated into the LP S PRA. The tasks comprising the comprehensive HRA methodology development are as follows: (1) identification of the human reliability related influences and associated human actions during LP S, (2) identification of potentially important LP S related human actions and appropriate HRA framework and quantification methods, and (3) incorporation and coordination of methodology development with other integrated PRA/HRA efforts. This paper describes the first task, i.e., the assessment of human reliability influences and any associated human actions during …
Date: January 1, 1993
Creator: Luckas, W. J.; Barriere, M. T.; Brown, W. S. (Brookhaven National Lab., Upton, NY (United States)); Wreathall, J. (Wreathall (John) and Co., Dublin, OH (United States)) & Cooper, S. E. (Science Applications International Corp., McLean, VA (United States))
Object Type: Article
System: The UNT Digital Library
Conceptual design report for the University of Rochester cryogenic target delivery system (open access)

Conceptual design report for the University of Rochester cryogenic target delivery system

The upgrade of the Omega laser at the University of Rochester's Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D[sub 2] or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.
Date: May 1, 1993
Creator: Fagaly, R. L.; Alexander, N. B.; Bourque, R. F.; Dahms, C. F.; Lindgren, J. R.; Miller, W. J. (General Atomics, San Diego, CA (United States)) et al.
Object Type: Report
System: The UNT Digital Library
Neutrino mass and mixing: Summary of the neutrino sessions (open access)

Neutrino mass and mixing: Summary of the neutrino sessions

A great deal of experimental and theoretical effort is underway to use neutrinos as a probe for Physics Beyond the Standard Model. Most of these efforts center on the questions of the possible existence of non zero neutrino mass and mixing. Sessions at the Moriond conferences have dealt with these questions at most of the meetings during the last several years and this year was no exception. Presentations covering most of the current and planned research in this field were presented and discussed. Although there is, at present, no definitive evidence for a non zero neutrino mass and mixing, several unresolved problems (in particular solar neutrinos) do seem to be indicating the likely existence of new neutrino properties. It is likely that before the end of this decade, efforts now being initiated will be able to determine whether or not the hints we are now seeing are really due to new physics.
Date: January 1, 1993
Creator: Bowles, T. J.
Object Type: Article
System: The UNT Digital Library
An interactive beam position monitor system simulator (open access)

An interactive beam position monitor system simulator

A system simulator has been implemented to aid the development of the RHIC position monitor system. Based on the LabVIEW software package by National Instruments, this simulator allows engineers and technicians to interactively explore the parameter space of a system during the design phase. Adjustable parameters are divided into three categories: beam, pickup, and electronics. The simulator uses these parameters in simple formulas to produce results in both time-domain and frequencydomain. During the prototyping phase, these simulated results can be compared to test data acquired with the same software package. The RHIC position monitor system is presented as an example, but the software is applicable to several other systems as well.
Date: March 1, 1993
Creator: Ryan, W. A. & Shea, T. J.
Object Type: Article
System: The UNT Digital Library
Vectorial electron transfer in spatially ordered arrays (open access)

Vectorial electron transfer in spatially ordered arrays

Progress was made on synthesis of new materials for directional electron transfer (block copolymers and helical oligopeptides), preparation and characterization of anisotropic composites bearing organics and inorganics, electrocatalysis (redox-activated catalysts), and surface modifications of metals and semiconductors.
Date: February 1, 1993
Creator: Fox, M. A.
Object Type: Report
System: The UNT Digital Library
Binding of carbon dioxide to metal macrocycles: Toward a mechanistic understanding of electrochemical and photochemical carbon dioxide reduction (open access)

Binding of carbon dioxide to metal macrocycles: Toward a mechanistic understanding of electrochemical and photochemical carbon dioxide reduction

Efforts were made to find effective catalysts for photochemical and electrochemical reduction of CO[sub 2]. We are studying the factors controlling excited-state lifetimes, electron-transfer rates to mediators/catalysts, properties of reduced mediators, binding of small molecules to reduced mediators, and reactivity of the mediators to yield the desired products. This document describes some of the results of binding on CO[sub 2] to metal macrocycles. The electrocatalytic activity of cobalt macrocycle complexes in reduction of CO[sub 2] in CO[sub 2]-saturated water at the Hg electrode is being studied. We are ready to study the mechanism and kinetics of the photochemical CO[sub 2] reduction in order to design more efficient photo-energy conversion systems. 19 refs.
Date: January 1, 1993
Creator: Fujita, E.
Object Type: Article
System: The UNT Digital Library
Six dimensional tracking simulator for H[sup [minus]] injection in AGS Booster (open access)

Six dimensional tracking simulator for H[sup [minus]] injection in AGS Booster

The effect of Coulomb multipole scattering on the beam emittance is studied with the 6 dimensional injection program ARCHSIM by A. Thiessen. Since the energy loss due to Bhabha scattering is small, the six dimensional simulation can be approximated into transverse 4 dimensional and longitudinal 2 dimensional tracking. The emittance growth agrees well with the multiple scattering theory. The beam loss occurs mainly in the adiabatic capture process in the longitudinal phase space.
Date: April 27, 1993
Creator: Lee, S. Y. & Tepikian, S.
Object Type: Report
System: The UNT Digital Library
GASFLOW: A computational model to analyze accidents in nuclear containment and facility buildings (open access)

GASFLOW: A computational model to analyze accidents in nuclear containment and facility buildings

GASFLOW is a finite-volume computer code that solves the time-dependent, compressible Navier-Stokes equations for multiple gas species. The fluid-dynamics algorithm is coupled to the chemical kinetics of combusting liquids or gases to simulate diffusion or propagating flames in complex geometries of nuclear containment or confinement and facilities' buildings. Fluid turbulence is calculated to enhance the transport and mixing of gases in rooms and volumes that may be connected by a ventilation system. The ventilation system may consist of extensive ductwork, filters, dampers or valves, and fans. Condensation and heat transfer to walls, floors, ceilings, and internal structures are calculated to model the appropriate energy sinks. Solid and liquid aerosol behavior is simulated to give the time and space inventory of radionuclides. The solution procedure of the governing equations is a modified Los Alamos ICE'd-ALE methodology. Complex facilities can be represented by separate computational domains (multiblocks) that communicate through overlapping boundary conditions. The ventilation system is superimposed throughout the multiblock mesh. Gas mixtures and aerosols are transported through the free three-dimensional volumes and the restricted one-dimensional ventilation components as the accident and fluid flow fields evolve. Combustion may occur if sufficient fuel and reactant or oxidizer are present and have an …
Date: 1993
Creator: Travis, J. R.; Nichols, B. D.; Wilson, T. L.; Lam, K. L.; Spore, J. W. & Niederauer, G. F.
Object Type: Article
System: The UNT Digital Library
Confirmatory measurement experiences at the Savannah River Site using a portable multi-channel analyzer (open access)

Confirmatory measurement experiences at the Savannah River Site using a portable multi-channel analyzer

A continuing concern within the DOE complex is the control and accountability of special nuclear material. It is not enough to have a paper record of accountable material but it must be physically verified on a statistical sampling basis. The Material Control and Accountability section of the Westinghouse Savannah River Company has been developing a technique to confirm radioactive isotopes of interest in the field using a battery operated portable multichannel analyzer and a sodium iodide gamma probe detector. A description of the instrument and examples of actual confirmatory measurements at a variety of locations and environments will be presented.
Date: January 1, 1993
Creator: Monson, R. W. & Jeffcoat, R. D.
Object Type: Article
System: The UNT Digital Library
Linear stability of stationary solutions of the Vlasov-Poisson system in three dimensions (open access)

Linear stability of stationary solutions of the Vlasov-Poisson system in three dimensions

Rigorous results on the stability of stationary solutions of the Vlasov-Poisson system are obtained in both the plasma physics and stellar dynamics contexts. It is proven that stationary solutions in the plasma physics (stellar dynamics) case are linearly stable if they are decreasing (increasing) functions of the local, i.e. particle, energy. The main tool in the analysis is the free energy of the system, a conserved quantity. In addition, an appropriate global existence result is proven for the linearized Vlasov-Poisson system and the existence of stationary solutions that satisfy the above stability condition is established.
Date: March 1, 1993
Creator: Batt, J.; Rein, G. (Muenchen Univ. (Germany). Mathematisches Inst.) & Morrison, P. J. (Texas Univ., Austin, TX (United States))
Object Type: Report
System: The UNT Digital Library
Burnup credit validation of SCALE-4 using light water reactor criticals (open access)

Burnup credit validation of SCALE-4 using light water reactor criticals

The ANSI/ANS 8.1 criticality safety standard recommends validation and benchmarking of the calculational methods used in evaluating criticality safety limits for away-from-reactor applications. The lack of critical experiments with burned light-water-reactor (LWR) fuel in racks or in casks necessitates the validation of burnup credit methods by comparison to LWR core criticals. These are relevant benchmarks because they test a methodology's ability to predict spent fuel isotopics and to evaluate the reactivity effects of heterogeneities and strong absorbers. Data are available to perform analyses at precise state points. The US Department of Energy Burnup Credit Program has sponsored analysis of selected reactor core critical configurations from commercial pressurized-water-reactors (PWRs) in order to validate an appropriate analysis methodology. The initial methodology used the SCALE-4 code system to analyze a set of reactor critical configurations from Virginia Power's Surry and North Anna reactors. The methodology has since been revised to simplify both the data requirements and the calculational procedure for the criticality analyst. This revised methodology is validated here by comparison to three reactor critical configurations from Tennessee Valley Authority's Sequoyah Unit 2 Cycle 3 and two from Virginia Power's Surry Unit 1 Cycle 2.
Date: January 1, 1993
Creator: Bowman, S. M.; Hermann, O. W. (Oak Ridge National Lab., TN (United States)) & Brady, M. C. (Sandia National Labs., Albuquerque, NM (United States))
Object Type: Article
System: The UNT Digital Library
Detection of subsurface defects in machined silicon nitride ceramics by optical scattering methods (open access)

Detection of subsurface defects in machined silicon nitride ceramics by optical scattering methods

Si[sub 3]N[sub 4] materials, from two manufacturers in the form of texture test bars, were studied by optical Fourier scattering methods. Subsurface defects were synthesized by either ultrasonically drilling or by grinding slots parallel to the surface. Because of unique optical transmission properties of ceramics subsurface defects, such as those likely to be caused by machining may be detected. S-polarized He-Ne laser light ([lambda] = 0.6328 [mu]m) was used as the light source. Specular reflections were detected by an optical Fourier method which incorporated cross-polarization. Analysis of scattered laser light was accomplished using a CCD-array camera, an 8-bit A/D converter, and a PC with locally written software. Results show that subsurface defects can be detected and that for the surface finishes studied, changes in signal-to-noise (S/N) are observable.
Date: January 1, 1993
Creator: Ellingson, W. A.; Ayaz, D. M.; Brada, M. P. & O'Connell, W.
Object Type: Article
System: The UNT Digital Library
Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction (open access)

Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction

An experimental set-up for accurate measurement of hydrogen generation rate in Lithium-Lead (Li[sub 17]Pb[sub 83]) Steam or water interactions has been designed. The most important features of the design include a pneumatic actuated quick opening and closing high temperature all stainless steel valve used to control the reaction time and the placement of most measuring devices below a water line to minimize leakage of the hydrogen collected. A PC based data acquisition and control system provides remote process sequencing, acquisition and control of all major components of the set-up. Initial tests indicate that the first design objective of maintaining leakproof gas collection chamber has been achieved. Initial pressure tests indicated that the pressure drop over a time span of 30 minutes was within the tolerance of the pressure transducer used to measure the pressure (within 0.690 kPa) at a nominal system pressure of 685 kPa. The experimental system hardware, data acquisition and control programs and data analysis program have been completed, tested and are currently functional.
Date: April 1, 1993
Creator: Biney, P. O.
Object Type: Report
System: The UNT Digital Library