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Effects of high beam rates on TPC's

Description: The TPC's (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchroton) were exposed to silicon ion fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to measure the distortion of the electric field caused by positive ions in the drift region. Results of these tests are presented and the consequences for the TPC based experiment at RHIC (Relativistic Heavy Ion Collider) are discussed.
Date: February 6, 1992
Creator: Etkin, A.; Eiseman, S. E.; Foley, K. J.; Hackenburg, R. W.; Longacre, R. S.; Love, W. A. et al.
Partner: UNT Libraries Government Documents Department
open access

Preliminary Results from the UCLA/SLAC Ultra-High Gradient CerenkovWakefield Accelerator Experiment

Description: The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. This experiment takes advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam has been successfully focused down and sent through varying lengths of fused silica capillary tubing with two … more
Date: February 6, 2008
Creator: Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travish, G.; Hogan, M.; Ischebeck, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Seismic Waves in Rocks with Fluids and Fractures

Description: Seismic wave propagation through the earth is often strongly affected by the presence of fractures. When these fractures are filled with fluids (oil, gas, water, CO{sub 2}, etc.), the type and state of the fluid (liquid or gas) can make a large difference in the response of the seismic waves. This paper will summarize some early work of the author on methods of deconstructing the effects of fractures, and any fluids within these fractures, on seismic wave propagation as observed in reflection s… more
Date: February 6, 2006
Creator: Berger, E. L.
Partner: UNT Libraries Government Documents Department
open access

Volume Independence in Large Nc QCD-like Gauge Theories

Description: Volume independence in large N{sub c} gauge theories may be viewed as a generalized orbifold equivalence. The reduction to zero volume (or Eguchi-Kawai reduction) is a special case of this equivalence. So is temperature independence in confining phases. A natural generalization concerns volume independence in ''theory space'' of quiver gauge theories. In pure Yang-Mills theory, the failure of volume independence for sufficiently small volumes (at weak coupling) due to spontaneous breaking of ce… more
Date: February 6, 2007
Creator: Kovtun, Pavel; Unsal, Mithat & Yaffe, Laurence G.
Partner: UNT Libraries Government Documents Department
open access

Charm and Charmonium Spectroscopy in BaBar

Description: The BABAR experiment at the PEP-II B-factory offers excellent opportunities in charm and charmonium spectroscopy. The recent observation of new states in the D{sub s} and in the charmonium mass regions revived the interest in this field. Recent BABAR results are presented.
Date: February 6, 2008
Creator: Negrini, M. & U., /Ferrara
Partner: UNT Libraries Government Documents Department
open access

The 13th International Symposium on Relations between Homogeneous and Heterogeneous Catalysis -- AnIntroduction

Description: Over forty years, there have been major efforts to aim at understanding the properties of surfaces, structure, composition, dynamics on the molecular level and at developing the surface science of heterogeneous and homogeneous catalysis. Since most catalysts (heterogeneous, enzyme and homogeneous) are nanoparticles, colloid synthesis methods were developed to produce monodispersed metal nanoparticles in the 1-10 nm range and controlled shapes to use them as new model catalyst systems in two-dim… more
Date: February 6, 2008
Creator: Somorjai, Gabor A.
Partner: UNT Libraries Government Documents Department
open access

Feasibility Evaluation and Retrofit Plan for Cold Crucible Induction Melter Deployment in the Defense Waste Processing Facility at Savannah River Site 8118

Description: Cold crucible induction melters (CCIM) have been proposed as an alternative technology for waste glass melting at the Defense Waste Processing Facility (DWPF) at Savannah River Site (SRS) as well as for other waste vitrification facilities. Proponents of this technology cite high temperature operation, high tolerance for noble metals and aluminum, high waste loading, high throughput capacity, and low equipment cost as the advantages over existing Joule Heated Melter (JHM) technology. The CCIM u… more
Date: February 6, 2008
Creator: Barnes, Allan B.; Iverson, Daniel C.; Adkins, Brannen J. & Tchemitcheff, Eric
Partner: UNT Libraries Government Documents Department
open access

ISS-flation

Description: Inflation may occur while rolling into the metastable supersymmetry-breaking vacuum of massive supersymmetric QCD. We explore the range of parameters in which slow-roll inflation and long-lived metastable supersymmetry breaking may be simultaneously realized. The end of slow-roll inflation in this context coincides with the spontaneous breaking of a global symmetry, which may give rise to significant curvature perturbations via inhomogeneous preheating. Such spontaneous symmetry breaking at the… more
Date: February 6, 2008
Creator: Craig, Nathaniel J. & /SLAC /Stanford U., ITP
Partner: UNT Libraries Government Documents Department
open access

Conference on decontamination and decommissioning of nuclear facilities

Description: A brief history of Decontamination and Decommissioning (D and D) experience at the Idaho National Engineering Laboratory is presented as an introduction to the status of current projects. Details are then presented as an introduction to the status of current projects. Details are then presented on a project to remove sodium from some major components of the Hallam reactor and on the Organic Moderated Reactor Experiment (OMRE) decommissioning project. Cost, schedule, waste volume, and other tech… more
Date: February 6, 1979
Creator: Meservey, R.H.
Partner: UNT Libraries Government Documents Department
open access

Capturing asteroids into bound orbits around the earth: Massive early return on an asteroid terminal defense system

Description: Nuclear explosives may be used to capture small asteroids (e.g., 20--50 meters in diameter) into bound orbits around the earth. The captured objects could be used for construction material for manned and unmanned activity in Earth orbit. Asteroids with small approach velocities, which are the ones most likely to have close approaches to the Earth, require the least energy for capture. They are particularly easy to capture if they pass within one Earth radius of the surface of the Earth. They co… more
Date: February 6, 1992
Creator: Hills, J.G.
Partner: UNT Libraries Government Documents Department
open access

Techniques for the generation and monitoring of vapors

Description: Controlled test atmospheres can be produced using a variety of techniques. Gases are usually generated by using flow dilution methods while vapors are produced by using solvent injection and vaporization, saturation, permeation and diffusion techniques. The resulting gas mixtures can be monitored and measured using flame ionization, photoionization, electrochemical and infrared analytical systems. An ideal system for the production of controlled test atmospheres would not only be able to genera… more
Date: February 6, 1981
Creator: Nelson, G.O.
Partner: UNT Libraries Government Documents Department
open access

Structural and thermal requirements for the tandem-mirror fusion-test-facility magnet system

Description: Structural requirements for the magnet system include unique spatial constraints and materials restrictions to meet the operational needs of the unusual configuration. All of the magnets are liquid helium cooled which represents about 1500 tonnes of 4.5 K structure in the vacuum environment of the large vessel. Magnet support structures must satisfy complex load conditions, including electromagnetic (both normal-operating and fault conditions) and seismically induced. Improved plasma confinemen… more
Date: February 6, 1981
Creator: VanSant, J. H. & Bulmer, R. H.
Partner: UNT Libraries Government Documents Department
open access

Noncontact material testing using laser energy deposition and interferometry

Description: A technique is described for the noncontact testing of materials using laser deposition to generate a stress pulse and interferometry to record the transient surface displacement. The dilatational wave speed can be measured and, in the particular case of rod or plate specimens, sufficient information can be obtained to evaluate the two elastic constants of an isotropic material. Several applications illustrating the advantages of the approach are summarized.
Date: February 6, 1978
Creator: Calder, C.A. & Wilcox, W.W.
Partner: UNT Libraries Government Documents Department
open access

Effect of propagation of coherent pulses on multiple-photon excitation

Description: The influence of laser pulse propagation on multiple-photon excitation of many-level absorbers, and the significance of SIRF for SF/sub 6/ dissociation are discussed.
Date: February 6, 1980
Creator: Shore, B. W.; Eberly, J. H. & Konopnicki, M. J.
Partner: UNT Libraries Government Documents Department
open access

Capturing asteroids into bound orbits around the earth: Massive early return on an asteroid terminal defense system

Description: Nuclear explosives may be used to capture small asteroids (e.g., 20--50 meters in diameter) into bound orbits around the earth. The captured objects could be used for construction material for manned and unmanned activity in Earth orbit. Asteroids with small approach velocities, which are the ones most likely to have close approaches to the Earth, require the least energy for capture. They are particularly easy to capture if they pass within one Earth radius of the surface of the Earth. They co… more
Date: February 6, 1992
Creator: Hills, J. G.
Partner: UNT Libraries Government Documents Department
open access

A Source-to-Source Architecture for User-Defined Optimizations

Description: The performance of object-oriented applications often suffers from the inefficient use of high-level abstractions provided by underlying libraries. Since these library abstractions are user-defined and not part of the programming language itself only limited information on their high-level semantics can be leveraged through program analysis by the compiler and thus most often no appropriate high-level optimizations are performed. In this paper we outline an approach based on source-to-source tr… more
Date: February 6, 2003
Creator: Schordan, M & Quinlan, D
Partner: UNT Libraries Government Documents Department
open access

Metastable metallic hydrogen glass

Description: The quest for metallic hydrogen has been going on for over one hundred years. Before hydrogen was first condensed into a liquid in 1898, it was commonly thought that condensed hydrogen would be a metal, like the monatomic alkali metals below hydrogen in the first column of the Periodic Table. Instead, condensed hydrogen turned out to be transparent, like the diatomic insulating halogens in the seventh column of the Periodic Table. Wigner and Huntington predicted in 1935 that solid hydrogen at 0… more
Date: February 6, 2001
Creator: Nellis, W J
Partner: UNT Libraries Government Documents Department
open access

The National Ignition Facility

Description: The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter-diameter target chamber and room for 100 diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion and matter at extreme energy densities and pressures. NIF's energetic laser beams will compress … more
Date: February 6, 2004
Creator: Miller, G H; Moses, E I & Wuest, C R
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: February 6, 2000
Creator: Chow, K.; Dietderich, D. R.; Gourlay, S. A.; Gupta, R.; Harnden, W.; Lietzke, A. F. et al.
Partner: UNT Libraries Government Documents Department
open access

Microseismic monitoring of the Chaveroo oil field, New Mexico

Description: Microseismicity was monitored in the Chaveroo oil field in southeastern New Mexico during, and for 5 weeks following, a pressurized stimulation of a well being prepared as an injector for a water flood operation. Three-thousand barrels of water were injected into the reservoir over a 5.5-hour period. Little seismicity was detected during the stimulation. Intermittent monitoring over a 5-week period following the injection indicated detectable seismicity occurring with activity levels varying in… more
Date: February 6, 1990
Creator: Rutledge, J. T. & Albright, J. N.
Partner: UNT Libraries Government Documents Department
open access

Thick target measurement of the 40Ca(alpha,gamma)44Ti reaction rate

Description: The thick-target yield for the {sup 40}Ca({alpha},{gamma}){sup 44}Ti reaction has been measured for E{sub beam} = 4.13, 4.54, and 5.36 MeV using both an activation measurement and online {gamma}-ray spectroscopy. The results of the two measurements agree. From the measured yield a reaction rate is deduced that is smaller than statistical model calculations. This implies a smaller {sup 44}Ti production in supernova compared to recently measured {sup 40}Ca({alpha},{gamma}){sup 44}Ti reaction rate… more
Date: February 6, 2009
Creator: Sheets, S A; Burke, J T; Scielzo, N D; Phair, L; Bleuel, D; Norman, E B et al.
Partner: UNT Libraries Government Documents Department
open access

NIF Target Fabrication

Description: No Description Available.
Date: February 6, 2013
Creator: Hamza, A V
Partner: UNT Libraries Government Documents Department
open access

Chemical and electronic characterization of cobalt in Lanthanumperovskites. Effects of Strontium substitution

Description: Two different cobaltites, LaCoO{sub 3} and La{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}}, have been prepared and characterized by means of high energy Co K-edge and low energy O K-edge X-ray absorption spectroscopy (XAS). The partial substitution of La(III) by Sr(II) species induces important changes in the reactivity and electronic state of the perovskite, while little or no changes can be detected in the formal oxidation state of cobalt atoms. The presence of strontium cations induces two main eff… more
Date: February 6, 2009
Creator: Hueso, Jose L.; Holgado, Juan P.; Pereniguez, Rosa; Mun, Simon; Salmeron, Miquel & Caballero, Alfonso
Partner: UNT Libraries Government Documents Department
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