An intercomparison of medium energy cross-section codes (open access)

An intercomparison of medium energy cross-section codes

Five medium energy proton reaction cases are selected for benchmarking nuclear model codes. The quantities calculated are isotopic activation yields for 180 MeV protons on Al and 40-200 MeV protons on Co, and double differential neutron emission spectra from Al, Zr-90 and Pb-208 for 35, 80, 160, 318, and 800 presented consist of three types: a closed form preequilibrium plus evaporation model, an intranuclear-cascade and evaporation model, and a model relying on nuclear systematics. The characteristics of each code are described. There are orders of magnitude differences in the time for each type of code to calculate neutron emission spectra, with codes using systematics, preequilibrium and intranuclear-cascade models requiring seconds, minutes and hours, respectively. Calculations are not compared with experiment in this initial study. For double differential neutron emission spectra, there is good overall agreement in magnitude among the different types of codes at forward angles. Differences where they occur at forward angles are greatest for the mid-energy neutrons emitted. At back angles the incident energy at which the best overall agreement is obtained is 160 MeV and the material for which the best overall agreement is obtained is Al. 4 refs., 7 tabs.
Date: May 1, 1988
Creator: Pearlstein, S.
Object Type: Report
System: The UNT Digital Library
Kokanee Stock Status and Contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1987 Annual Progress Report. (open access)

Kokanee Stock Status and Contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1987 Annual Progress Report.

Estimated kokanee Oncorhynchus nerka abundance in Lake Pend Oreille was 6.01 million during late summer 1987. This estimate is 40% higher than the 1986 estimate and is the second largest population estimate since 1977. Higher abundance is predominantly a result of enhanced fry survival and recruitment. Hatchery-reared fry contribution was 22% of total fry recruitment in 1987, compared to 8% in 1986, and resulted from a fivefold increase in survival. Much of this improvement can be attributed to the large (52 mm) fry produced at Cabinet Gorge Hatchery in 1987 and represents the first measurable contribution of the new hatchery to the kokanee rehabilitation program. Survival of hatchery-reared fry released into Clark Fork River was nearly one-half that of fry released into Sullivan Springs due to poor flow conditions and potentially high predation during migration from Cabinet Gorge Hatchery to Lake Pend Oreille. Wild fry survival was enhanced by early availability of forage (cladocern zooplankton) during fry emergence in late spring. Cladoceran production began three weeks earlier in 1987 than 1986, which resulted from reduced Mysis abundance and earlier thermal stratification of Lake Pend Oreille, which helped segregate cladocerans from mysid predation. Kokanee dry otolith coding was evaluated to provide …
Date: May 1, 1988
Creator: Bowles, Edward C.
Object Type: Report
System: The UNT Digital Library
Labor Force Estimates for Texas Counties, May 1988 (open access)

Labor Force Estimates for Texas Counties, May 1988

Monthly compilation of estimated statistics listed by Texas county for civilian labor force (C.L.F.), employment, unemployment, and overall rate.
Date: May 1988
Creator: Texas Employment Commission. Economic Research and Analysis Department.
Object Type: Report
System: The Portal to Texas History
Laboratory work in support of West Valley glass development (open access)

Laboratory work in support of West Valley glass development

Over the past six years, Pacific Northwest Laboratory (PNL) has conducted several studies in support of waste glass composition development and testing of glass compositions suitable for immobilizing the nuclear wastes stored at West Valley, New York. As a result of pilot-scale testing conducted by PNL, the glass composition was changed from that originally recommended in response to changes in the waste stream, and several processing-related problems were discovered. These problems were solved, or sufficiently addressed to determine their likely effect on the glass melting operations to be conducted at West Valley. This report describes the development of the waste glass composition, WV-205, and discusses solutions to processing problems such as foaming and insoluble sludges, as well as other issues such as effects of feed variations on processing of the resulting glass. An evaluation of the WV-205 glass from a repository perspective is included in the appendix to this report.
Date: May 1, 1988
Creator: Bunnell, L.R.
Object Type: Report
System: The UNT Digital Library
LFCM (liquid-fed ceramic melter) vitrification technology: Quarterly progress report, January--March 1987 (open access)

LFCM (liquid-fed ceramic melter) vitrification technology: Quarterly progress report, January--March 1987

This report is compiled by the Nuclear Waste Treatment Program and the Hanford Waste Vitrification Program at Pacific Northwest Laboratory to describe the progress in developing, testing, applying and documenting liquid-fed ceramic melter vitrification technology. Progress in the following technical subject areas during the second quarter of FY 1987 is discussed: melting process chemistry and glass development, feed preparation and transfer systems, melter systems, canister filling and handling systems, and process/product modeling. 23 refs., 14 figs., 10 tabs.
Date: May 1, 1988
Creator: Brouns, R. A.; Allen, C. R. & Powell, J. A. (comps.)
Object Type: Report
System: The UNT Digital Library
Liquid metal blanket module testing and design for ITER/TIBER II (open access)

Liquid metal blanket module testing and design for ITER/TIBER II

A major goal for ITER is the testing of nuclear components to demonstrate the integrated performance of the most attractive concepts that can lead to a commercial fusion reactor. As part of the ITER/TIBER II study, the test program and design of test models were examined for a number of blanket concepts. The work at Argonne National Laboratory focused on self-cooled liquid metal blankets. A test program for liquid metal blankets was developed based upon the ITER/TIBER II operating schedule and the specific data needs to resolve the key issues for liquid metals. Testing can begin early in reactor operation with liquid metal MHD tests to confirm predictive capability. Combined heat transfer/MHD tests can be performed during initial plasma operation. After acceptable heat transfer performance is verified, tests to determine the integrated high temperature performance in a neutron environment can begin. During the high availability phase operation, long term performance and reliability tests will be performed. It is envisioned that a companion test program will be conducted outside ITER to determine behavior under severe accident conditions and upper performance limits. A detailed design of a liquid metal test module and auxiliary equipment was also developed. The module followed the design …
Date: May 1, 1988
Creator: Mattas, R. F.; Cha, Y.; Finn, P. A.; Majumdar, S.; Picologlou, B.; Stevens, H. et al.
Object Type: Report
System: The UNT Digital Library
The longitudinal coupling impedance of a toroidal vacuum chamber in the low frequency range (open access)

The longitudinal coupling impedance of a toroidal vacuum chamber in the low frequency range

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Date: May 1, 1988
Creator: Ruggiero, Alessandro G.
Object Type: Report
System: The UNT Digital Library
Low-energy structure of four-dimensional superstrings (open access)

Low-energy structure of four-dimensional superstrings

The N = 1, d = 4 supergravity theories derived as the low-energy limit of four-dimensional superstrings are discussed, focusing on the properties of their effective potentials. Gauge symmetry breaking is possible along several flat directions. A class of superpotential modifications is introduced, which describes supersymmetry breaking with vanishing cosmological constant and Str M{sup 2} = 0 at any minimum of the tree level potential. Under more restrictive assumptions, there are minima with broken supersymmetry at which also Str f(M{sup 2}) = 0 for any function f, so that the whole one-loop cosmological constant vanishes. This result is interpreted in terms of a new discrete boson-fermion symmetry, relating particles whose helicities differ by 3/2, e.g., the graviton and the dilatino.' 21 refs.
Date: May 1, 1988
Creator: Zwirner, F.
Object Type: Article
System: The UNT Digital Library
Marine Education, Volume 8, Number 4, May 1988 (open access)

Marine Education, Volume 8, Number 4, May 1988

Quarterly newsletter of the Marine Education Sea Grant College Program at Texas A&M University discussing news and activities of the Program and other topics related to marine sciences.
Date: May 1988
Creator: Texas A & M University. Sea Grant College Program.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Material behavior and materials problems in TFTR (Tokamak Fusion Test Reactor) (open access)

Material behavior and materials problems in TFTR (Tokamak Fusion Test Reactor)

This paper reviews the experience with first-wall materials over a 20-month period of operation spanning 1985--1987. Experience with the axisymmetric inner wall limiter, constructed of graphite tiles, will be described including the necessary conditioning procedures needed for impurity and particle control of high power ({le}20 MW) neutral injection experiments. The thermal effects in disruptions have been quantified and no significant damage to the bumper limiter has occurred as a result of disruptions. Carbon and metal impurity redeposition effects have been quantified through surface analysis of wall samples. Estimates of the tritium retention in the graphite limiter tiles and redeposited carbon films have been made based on analysis of deuterium retention in removed graphite tiles and wall samples. New limiter structures have been designed using a 2D carbon/carbon (C/C) composite material for RF antenna protection. Laboratory tests of the important thermal, mechanical and vacuum properties of C/C materials will be described. Finally, the last series of experiments in TFTR with in-situ Zr/Al surface pumps will be described. Problems with Ar/Al embrittlement have led to the removal of the getter material from the in-torus environment. 53 refs., 8 figs., 3 tabs.
Date: May 1, 1988
Creator: Dylla, H. F.; Ulrickson, M. A.; Owens, D. K.; Heifetz, D. B.; Mills, B. E.; Pontau, A. E. et al.
Object Type: Article
System: The UNT Digital Library
Maximum entropy signal restoration with linear programming (open access)

Maximum entropy signal restoration with linear programming

Dantzig's bounded-variable method is used to express the maximum entropy restoration problem as a linear programming problem. This is done by approximating the nonlinear objective function with piecewise linear segments, then bounding the variables as a function of the number of segments used. The use of a linear programming approach allows equality constraints found in the traditional Lagrange multiplier method to be relaxed. A robust revised simplex algorithm is used to implement the restoration. Experimental results from 128- and 512-point signal restorations are presented.
Date: May 1, 1988
Creator: Mastin, G. A. & Hanson, R. J.
Object Type: Report
System: The UNT Digital Library
Measurement of the left-right asymmetry in pion-proton radiative exchange and charge exchange scattering from 301 to 625 MeV/c on a transversely polarized target (open access)

Measurement of the left-right asymmetry in pion-proton radiative exchange and charge exchange scattering from 301 to 625 MeV/c on a transversely polarized target

The left-right asymmetry A/sub N/ in ..pi../sup /minus//p ..-->.. ..gamma..n has been measured at p/sub ..pi.. = 301, 316, 427, 471, 547, 586, and 625 MeV/c using a transversely polarized target. The final-state neutron and gamma were detected in coincidence by two states of matching neutron and gamma detectors at gamma angles centered around 90/degree and 110/degree/ c.m. A gamma detector consisted of an array of 15 counters, each was 15/times/15/times/25 cm/sup 3/ block of lead-glass. A neutron detector consisted of 15 counters also, each one was a cylindrical plastic scintillator 7.6 cm in diameter and 45.7 cm long. The A/sub N/ results are compared with the predictions from the most recent single-pion photoproduction partial-wave analysis by Arai and Fujii. The agreement is poor, casting doubt on the correctness of the value for the radiative-decay amplitude of the neutral Roper resonance now in use. A comparison is made with the 90/degree/recoil proton polarization data of the inverse reaction derived from ..gamma..d scattering, there are substantial discrepencies. Charge exchange (..pi../sup /minus/p/ ..-->.. ..gamma../degree/n) events were the major yield in this experiment. Very precise values of the charge exchange analyzing power were obtained with an error of typically 3%. The charge exchange …
Date: May 1, 1988
Creator: Kim, George Jung-Kwang
Object Type: Report
System: The UNT Digital Library
Measurements of Pressure Drop and Heat Transfer in Turbulent Pipe Flows of Particulate Slurries (open access)

Measurements of Pressure Drop and Heat Transfer in Turbulent Pipe Flows of Particulate Slurries

Report on the results of a study to develop phase-change slurries as advanced energy transmission fluids.
Date: May 1988
Creator: Liu, K. V.; Choi, U. S. & Kasza, Kenneth Edmund
Object Type: Report
System: The UNT Digital Library
Metal-air battery assessment (open access)

Metal-air battery assessment

The objective of this report is to evaluate the present technical status of the zinc-air, aluminum/air and iron/air batteries and assess their potential for use in an electric vehicle. In addition, this report will outline proposed research and development priorities for the successful development of metal-air batteries for electric vehicle application. 39 refs., 25 figs., 11 tabs.
Date: May 1, 1988
Creator: Sen, R. K.; Van Voorhees, S. L. & Ferrel, T.
Object Type: Report
System: The UNT Digital Library
Milliwatt generator project: Progress report, April 1982-March 1983 (open access)

Milliwatt generator project: Progress report, April 1982-March 1983

This report covers progress on the Milliwatt Generator Project during April 1982-March 1983. Activities included fuel processing and characterization, production of heat sources, fabrication of pressure-burst test units, compatibility studies, examination of surveillance units, and impact testing. The fuel was plutonium-238 dioxide. 4 refs., 28 figs., 17 tabs.
Date: May 1, 1988
Creator: Rinehart, G. H. & Latimer, T. W.
Object Type: Report
System: The UNT Digital Library
Milliwatt generator project: Progress report, April 1983--March 1984 (open access)

Milliwatt generator project: Progress report, April 1983--March 1984

This report covers progress on the Milliwatt Generator Project during April 1983--March 1984. Activities included (plutonium 238 oxide) fuel processing and characterization, production of heat sources, fabrication of pressure-burst test units, compatibility studies, impact testing, examination of surveillance units, Inconel weld development, and qualilty assurance.
Date: May 1, 1988
Creator: Rinehart, G.H. & Latimer, T.W.
Object Type: Report
System: The UNT Digital Library
Mineralogy of drill hole UE-25p#1 at Yucca Mountain, Nevada (open access)

Mineralogy of drill hole UE-25p#1 at Yucca Mountain, Nevada

Drill hole UE-25p{number_sign}1 is located east of the candidate repository block at Yucca Mountain, Nevada, and as such provides information on the geology of the accessible environment. The hole was drilled to a depth of 1807 m (5923 ft) and is unique in that it penetrates tuffs that are older than any volcanic units previously encountered in drill holes at Yucca Mountain. In addition, it is the only hole drilled to date that penetrates the base of the tuff sequence and enters the underlying Paleozoic dolomite basement. We have examined the mineralogy of drill cuttings, core, and sidewall samples from drill hole UE-25p{number_sign}1 is similar to that in the other drill holes examined at Yucca Mountain. The only significant differences in mineralogy from other drill holes include the presence of dolomite in the Paleozoic carbonate rocks and the occurrence of up to 3% laumontite, a Ca-zeolite, in four samples of the Lithic Ridge Tuff. 15 refs., 5 figs., 4 tabs.
Date: May 1, 1988
Creator: Chipera, S. J. & Bish, D. L.
Object Type: Report
System: The UNT Digital Library
A model for electron/ion recombination in ionization chambers (open access)

A model for electron/ion recombination in ionization chambers

The recombination of free electrons and positive ions along charged particle tracks in gases has been modeled using electron tranport equations, which assume homogeneous distribution in the vicinity of the tracks. The equations include space charge terms, which have been negelected in previous models. A formula for the electron yield as a function of detector applied potential is obtained from a perturbation solution valid when the ratio of the Debye length to the charge column radius is larger then unity. When this ratio is very large, the formula reduces to that of previous models. Pulse height measurements in a /sup 3/He ionization chamber indicate 2% to 30% losses to recombination which vary with applied field, particle type, and energy. Using reasonable values for the electron transport coefficients, the calculated loss of signal to recommendation is generally in agreement with experiment, but the variation with applied bias is stronger in the experiment.
Date: May 1, 1988
Creator: Sailor, W. C.
Object Type: Report
System: The UNT Digital Library
Near surface chemistry and corrosion behavior of excimer laser surface-melted AISI type 304 stainless steel (open access)

Near surface chemistry and corrosion behavior of excimer laser surface-melted AISI type 304 stainless steel

The effects of excimer laser surface melting on the near-surface chemistry, and corrosion behavior of AISI 304 stainless steel have been examined as a function of total energy deposited on the specimen. The surface chemistry resulting from the laser treatments has been examined using Auger electron spectroscopy. Electrochemical methods were used to monitor the corrosion behavior of the specimens in deaerated 0.1 M NaCl. Electron microscopy was used to characterize the extent of local corrosion of the specimens. Laser treatment was observed to increase the chromium concentration of the surface oxide and to reduce the number of pits. Two types of pits were observed on untreated material, but only one type of pit occurred after laser treatment. 7 refs., 5 figs.
Date: May 1, 1988
Creator: Baer, Donald R.; Frydrych, Daniel J. & Jervis, Thomas R.
Object Type: Article
System: The UNT Digital Library
Neutron spectroscopy on TFTR (Tokamak Fusion Test Reactor) (open access)

Neutron spectroscopy on TFTR (Tokamak Fusion Test Reactor)

This paper describes the use of an /sup 3/He ionization chamber for neutron spectroscopy on TFTR during 1987. The ion temperature was measured using neutron spectroscopy for one set of ohmically heated plasmas. The deduced ion temperatures agreed to within 20% with those measured by other diagnostics. 11 refs., 11 figs., 1 tab.
Date: May 1, 1988
Creator: Nishitani, T. & Strachan, J. D.
Object Type: Report
System: The UNT Digital Library
New Developments in Biotechnology: Field-Testing Engineered Organisms: Genetic and Ecological Issues (open access)

New Developments in Biotechnology: Field-Testing Engineered Organisms: Genetic and Ecological Issues

This report in the series illustrates a range of options for congressional action in three major areas of public policy related to this application of biotechnology: the criteria for review of planned introductions for potential risk, the administrative mechanisms for applying such review criteria, and the research base supporting planned introductions.
Date: May 1988
Creator: United States. Congress. Office of Technology Assessment.
Object Type: Report
System: The UNT Digital Library
News & Views, Volume 10, Number 5, May 1988 (open access)

News & Views, Volume 10, Number 5, May 1988

Newsletter of the Texas Rehabilitation Commission discussing information about the Commission as well as news, events, and other relevant information.
Date: May 1988
Creator: Texas Rehabilitation Commission
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Nonlinear gyrokinetic equations for tokamak microturbulence (open access)

Nonlinear gyrokinetic equations for tokamak microturbulence

A nonlinear electrostatic gyrokinetic Vlasov equation, as well as Poisson equation, has been derived in a form suitable for particle simulation studies of tokamak microturbulence and associated anomalous transport. This work differs from the existing nonlinear gyrokinetic theories in toroidal geometry, since the present equations conserve energy while retaining the crucial linear and nonlinear polarization physics. In the derivation, the action-variational Lie perturbation method is utilized in order to preserve the Hamiltonian structure of the original Vlasov-Poisson system. Emphasis is placed on the dominant physics of the collective fluctuations in toroidal geometry, rather than on details of particle orbits. 13 refs.
Date: May 1, 1988
Creator: Hahm, T. S.
Object Type: Report
System: The UNT Digital Library
Numerical modeling of the thermal and hydrological environment around a nuclear waste package using the equivalent continuum approximation: Horizontal emplacement (open access)

Numerical modeling of the thermal and hydrological environment around a nuclear waste package using the equivalent continuum approximation: Horizontal emplacement

In support of the investigations for an underground high-level nuclear waste repository at Yucca Mountain, Nevada, we have performed computer simulations of the immediate thermal and hydrological environment around a nuclear waste package. Calculations of this type will be needed for waste package design, performance assessment, and radionuclide transport analyses. Two dimensional computer simulations using a modified version of the TOUGH code were run for an idealized configuration derived from the COVE3 benchmarking effort consisting of a single spent fuel waste package with laterally periodic boundary conditions. The model domain extended downward to the water table and upward to the ground level. Fluid behavior in the rock was modeled using the equivalent continuum approximation. Runs were made with surface water influx rates at the surface set to 0.1, 0.5, and 1.0 mm/yr. A significant amount of code modification and development was needed in order to develop the capability to run these types of problems out to the long time spans required. 26 refs., 59 figs.
Date: May 1, 1988
Creator: Nitao, J. J.
Object Type: Report
System: The UNT Digital Library