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On reactor type comparisons for the next generation of reactors

Description: In this paper, we present a broad comparison of studies for a selected set of parameters for different nuclear reactor types including the next generation. This serves as an overview of key parameters which provide a semi-quantitative decision basis for selecting nuclear strategies. Out of a number of advanced reactor designs of the LWR type, gas cooled type, and FBR type, currently on the drawing board, the Advanced Light Water Reactors (ALWR) seem to have some edge over other types of the nex… more
Date: August 22, 1991
Creator: Alesso, H.P. & Majumdar, K.C.
Partner: UNT Libraries Government Documents Department
open access

Hot-Recycled-Solid pilot plant 1991 status report

Description: At Lawrence Livermore National Laboratory, we are studying above ground oil shale retorting and have developed the LLNL Hot-Recycled-Solid (HRS) process as a generic second-generation, rapid pyrolysis retorting system in which recycled shale is the solid heat carrier. In 1984--1987, we operated a 1 tonne-per-day HRS pilot plant to study retorting chemistry in an actual recirculation loop. In 1989 we upgraded our laboratory pilot plant to process 4 tonne-per-day of commercially sized shale, allo… more
Date: April 22, 1991
Creator: Cena, R.J.
Partner: UNT Libraries Government Documents Department
open access

Gamma-ray spectrometry of LDEF samples at SRL

Description: A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of {sup 22}Na, {sup 46}Sc, {sup 51}Cr, {sup 54}Mn, {sup 56}Co, {sup 57}Co, {sup 58}Co, and {sup 60}Co. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunn… more
Date: July 22, 1991
Creator: Winn, Willard G.
Partner: UNT Libraries Government Documents Department
open access

DSP: A detailed spectroscopy postprocessor for H-, He-, and Li-like ions

Description: A detailed plasma spectroscopy postprocessor for H-, He-, and Li-like ions with 6 {le} Z {le} 26 has been constructed. The structure of the code and the physics contained within it will be described and a sample application given. 15 refs., 5 figs.
Date: February 22, 1991
Creator: Keane, C.J.; Lee, R.S. (Lawrence Livermore National Lab., CA (USA)) & Grandy, J.P. (Massachusetts Inst. of Tech., Cambridge, MA (USA))
Partner: UNT Libraries Government Documents Department
open access

Modeling the Longitudinal Wall Impedance Instability in Heavy Ion Beams Using an R-Z PIC Code

Description: The effects of the longitudinal wall impedance instability in a heavy ion beam are of great interest for heavy ion fusion drivers. We are studying this instability using the R-Z thread of the WARP PIC code. We describe the code and our model of the impedance due to the accelerating modules of the induction LINAC as a resistive wall. We present computer simulations which illustrate this instability. 2 refs., 2 figs., 1 tab.
Date: February 22, 1991
Creator: Callahan, D. A.; Langdon, A. B.; Friedman, A.; Grote, D. P. & Haber, I.
Partner: UNT Libraries Government Documents Department
open access

Medium-energy neutrino physics

Description: A selection of opportunities for neutrino physics from a source generated from pions that decay in flight and at rest is described. The present source at LAMPF has a duty factor of about 6%; improvements in opportunities that emerge from a source using a pulse 0.25 {mu}sec long from a proton storage ring are also described. 7 refs., 9 figs.
Date: November 22, 1991
Creator: White, D. Hywel
Partner: UNT Libraries Government Documents Department
open access

Search for the top quark with CDF

Description: During the 1988--89 Tevatron Collider run the CDF detector has collected data for an integrated luminosity of 4.4 pb{sup {minus}1}. The sample has been used to search for the top quark in several topologies. Preliminary results show that a top mass below 89 GeV is excluded at the 95% confidence level, thus extending the limit of 77 GeV previously published by CDF. 14 refs., 8 figs.
Date: January 22, 1991
Creator: Barbaro-Galtieri, A. (Lawrence Berkeley Lab., CA (USA))
Partner: UNT Libraries Government Documents Department
open access

A pulsed lepton source at LAMPF

Description: A Pulsed Lepton Source is being considered at the LAMPF facility at Los Alamos National Laboratory. The source plan is described together with a description of the components and performance as they exist at present. 9 figs.
Date: November 22, 1991
Creator: White, D. Hywel
Partner: UNT Libraries Government Documents Department
open access

PILAC: A pion linac facility for 1-GeV pion physics at LAMPF

Description: A design study for a Pion Linac (PILAC) at LAMPF is under way at Los Alamos. We present here a reference design for a system of pion source, linac, and high-resolution beam line and spectrometer that will provide 10{sup 9} pions per second on target and 200-keV resolution for the ({pi}{sup +}, K{sup +}) reaction at 0.92 GeV. A general-purpose beam line that delivers both positive and negative pions in the energy range 0.4-1.1 GeV is included, thus opening up the possibility of a broad experimen… more
Date: November 22, 1991
Creator: Thiessen, H.A. & White, D.H.
Partner: UNT Libraries Government Documents Department
open access

Orientational phase transitions in alloys. [CsPb; NaSn]

Description: Plastic crystal behavior is observed in semiconducting CsPb and NaSn at high temperature (600 and 500 C, respectively). This behavior is associated with M{sub 4}{sup 4{minus}} or A{sub 4}M{sub 4} structural units orientationally disordering about 50 C below the melting point where translational disorder sets in. This orientational disorder is different in the two phases, exhibiting jump reorientations in CsPb and a more isotropic behavior in NaSn. In other Zintl compounds such as KPb, there is … more
Date: September 22, 1992
Creator: Saboungi, M.L.; Johnson, G.K. & Price, D.L.
Partner: UNT Libraries Government Documents Department
open access

['UNT professor offers expertise of Barnes collection', May 22, 1994]

Description: An article from the newspaper the Denton Record-Chronicle written by Tim Leenerts. The piece discusses the lectures given by Dr. R. William McCarter on the Barnes collection, which was being shown at the Kimbell Art Museum in Fort Worth.
Date: May 22, 1994
Creator: Leenerts, Tim
Partner: UNT Libraries Special Collections
open access

Physics goals and signatures at the SSC

Description: The physics goals of the SSC are presented and the capabilities of the SSC to achieve them are assessed. New gauge bosons, electroweak symmetry breaking, supersymmetry, and quark substructure are the primary targets for particle physics research and the SSC is the most effective means to find them. 2 refs., 4 figs.
Date: May 22, 1990
Creator: Cahn, R.N.
Partner: UNT Libraries Government Documents Department
open access

Using geophysical techniques to control in situ thermal remediation

Description: Monitoring the thermal and hydrologic processes that occur during thermal environmental remediation programs in near real-time provides essential information for controlling the process. Geophysical techniques played a crucial role in process control as well as for characterization during the recent Dynamic Underground Stripping Project demonstration in which several thousand gallons of gasoline were removed from heterogeneous soils both above and below the water table. Dynamic Underground Stri… more
Date: January 22, 1994
Creator: Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M.; Goldman, R.; Kayes, D. et al.
Partner: UNT Libraries Government Documents Department
open access

A point-centered diffusion differencing for unstructured meshes in 3-D

Description: We describe a point-centered diffusion discretization for 3-D unstructured meshes of polyhedra. The method has several attractive qualities, including second-order accuracy and preservation of linear solutions. A potential drawback to the scheme is that the diffusion matrix is asymmetric, in general. Results of numerical test problems illustrate the behavior of the scheme.
Date: September 22, 1994
Creator: Palmer, T. S.
Partner: UNT Libraries Government Documents Department
open access

Gamma-ray spectrometry of LDEF samples at SRL

Description: A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of {sup 22}Na, {sup 46}Sc, {sup 51}Cr, {sup 54}Mn, {sup 56}Co, {sup 57}Co, {sup 58}Co, and {sup 60}Co. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunn… more
Date: July 22, 1991
Creator: Winn, W. G.
Partner: UNT Libraries Government Documents Department
open access

Measurement of local void fraction in a ribbed annulus

Description: The computer code FLOWTRAN-TF is used to analyze hypothetical hydraulic accidents for the nuclear reactor at the Savannah River Site. During a hypothetical Large Break Loss-of-Coolant Accident (LOCA), reactor assemblies would contain a two-phase mixture of air and water which flows downward. Reactor assemblies consist of nested, ribbed annuli. Longitudinal ribs divide each annulus into four subchannels. For accident conditions, air and water can flow past ribs from one subchannel to another. Fo… more
Date: December 22, 1992
Creator: Steimke, J. L.
Partner: UNT Libraries Government Documents Department
open access

Overview of WARP, a particle code for Heavy Ion Fusion

Description: The beams in a Heavy Ion beam driven inertial Fusion (HIF) accelerator must be focused onto small spots at the fusion target, and so preservation of beam quality is crucial. The nonlinear self-fields of these space-charge-dominated beams can lead to emittance growth; thus a self-consistent field description is necessary. We have developed a multi-dimensional discrete-particle simulation code, WARP, and are using it to study the behavior of HIF beams. The code`s 3d package combines features of a… more
Date: February 22, 1993
Creator: Friedman, A.; Grote, D. P.; Callahan, D. A.; Langdon, A. B. & Haber, I.
Partner: UNT Libraries Government Documents Department
open access

PIC space-charge emission with finite {Delta}t and {Delta}z

Description: A new algorithm for space charge emission has been developed to provide the correct (to a few percent) Child-Langmuir steady-state current limits as the number of mesh points in the voltage gap drops to O(10). Further, the transient behavior of such flows compares well with idealized, analytic cases, lending confidence as we extend these algorithms into full RZ geometry with curved emitting surfaces to investigate transient characteristics of realistic injector designs.
Date: February 22, 1993
Creator: Hewett, D. W. & Chen, Yu-Jiuan
Partner: UNT Libraries Government Documents Department
open access

High- and low-temperature bonding techniques for microstructures

Description: The ability to bond together two or more silicon wafers greatly expands the variety and complexity of silicon microstructures that can be designed and fabricated. At LLNL, microstructures have been used for many years as hardware in scientific experiments. The activity has recently been expanded into other areas to include microinstruments for biomedical applications and for chemical analysis. Both high temperature (1100{degrees}C) bonding techniques have been used, depending on the application… more
Date: June 22, 1993
Creator: Ciarlo, D. R.
Partner: UNT Libraries Government Documents Department
open access

A new approach to modeling linear accelerator systems

Description: A novel computer code is being developed to generate system level designs of radiofrequency ion accelerators with specific applications to machines of interest to Accelerator Driven Transmutation Technologies (ADTT). The goal of the Accelerator System Model (ASM) code is to create a modeling and analysis tool that is easy to use, automates many of the initial design calculations, supports trade studies used in accessing alternate designs and yet is flexible enough to incorporate new technology … more
Date: July 22, 1994
Creator: Gillespie, G. H.; Hill, B. W. & Jameson, R. A.
Partner: UNT Libraries Government Documents Department
open access

Basic criticality relations for gas core design

Description: Minimum critical fissile concentrations are calculated for U-233, U-235, Pu-239, and Am-242m mixed homogeneously with hydrogen at temperatures to 15,000K. Minimum critical masses of the same mixtures in a 1000 liter sphere are also calculated. It is shown that propellent efficiencies of a gas core fizzler engine using Am-242m as fuel would exceed those in a solid core engine as small as 1000L operating at 100 atmospheres pressure. The same would be true for Pu-239 and possibly U-233 at pressure… more
Date: May 22, 1992
Creator: Tanner, J. E.
Partner: UNT Libraries Government Documents Department
open access

Primary water stress corrosion cracking of Alloy 600: Effects of processing parameters

Description: Correlations of stress corrosion cracking (SCC) data in deaerated water with temperature, stress, metallography, and processing for laboratory test specimens are presented. Initiation time data show that a low temperature anneal and resulting absence of grain boundary carbides result in a material having increased susceptibility to SCC. Data also show that hot worked and annealed Alloy 600 is more resistant than cold worked and annealed material, both having carbide decorated grain boundaries. … more
Date: October 22, 1993
Creator: Seman, D. J.; Webb, G. L. & Parrington, R. J.
Partner: UNT Libraries Government Documents Department
open access

Hazardous waste cleanup at federal facilities: Need for an integrated policy

Description: The U.S. Department of Energy (DOE) has generated and disposed of large volumes of hazardous and radioactive waste as a result of 50 years of nuclear weapons production. DOE is now faced with the problem of remediating its more than 13,000 hazardous waste sites. To be effective for the good of the environment and public health, our nation`s hazardous waste policy must first address several questions: What is the level of risk at federal facilities? (Is remediation really necessary?) Can and sho… more
Date: September 22, 1993
Creator: Travis, C. C. & Ladd, B.
Partner: UNT Libraries Government Documents Department
open access

Fabrication and Test Results of a Nb3Sn Superconducting Racetrack Dipole Magnet

Description: A 'proof-of-principle' Nb{sub 3}Sn superconducting dual-bore dipole magnet was built from racetrack coils, as a first step in a program to develop an economical, 15 Tesla, accelerator-quality magnet. The mechanical design and magnet fabrication procedures are discussed. No training was required to achieve temperature-dependent plateau currents, despite several thermal cycles that involved partial magnet disassembly and substantial pre-load variations. Subsequent magnets are expected to approach… more
Date: March 22, 1999
Creator: Chow, K.; Dietderich, D. R.; Gourlay, S. A.; Gupta, R.; Harnden, W.; Lietzke, A. F. et al.
Partner: UNT Libraries Government Documents Department
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