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Study of optical model parameters for high energy neutron cross sections from 5 to 50 MeV in the mass-140 region

Description: A study of the neutron optical potential on nuclei near mass-140 was begun to extend the energy range and improve the precision of previous neutron total cross section measurements. The extended energy range of this measurement reveals maxima and minima in the total cross section that are evidence of the nuclear Ramsauer effect. A 100-MeV linear accelerator is used to produce a continuum of neutron energies from a Ta-Be conversion target. A 250-meter flight path is used to measure neutron energ… more
Date: May 8, 1980
Creator: Phillips, T.W.; Camarda, H.S. & White, R.M.
Partner: UNT Libraries Government Documents Department
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Beyond Spin-Orbit: Probing Electron Correlation in the Pu 5f States

Description: Experiments planned to address the issue of electron correlation in the Pu 5f states are described herein. The key is the utilization of the Fano Effect, the observation of spin polarization in nonmagnetic systems, using chiral excitation such as circularly polarized X-rays.
Date: May 8, 2006
Creator: Tobin, J G
Partner: UNT Libraries Government Documents Department
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Temporal Dispersion of a Spectrometer

Description: The temporal dispersion of an optical spectrometer has been characterized for a variety of conditions related to optical diagnostics to be fielded at the National Ignition Facility (e.g., Full-Aperture Backscatter Station, Thomson Scattering). Significant time smear is introduced into these systems by the path length difference through the spectrometer. The temporal resolution can be calculated to depend only on the order of the grating, wavelength, and the number of grooves illuminated. To enh… more
Date: May 8, 2008
Creator: Visco, A; Drake, R P; Froula, D H & Glenzer, S H
Partner: UNT Libraries Government Documents Department
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Diagnostic Components in Harsh Radiation Environments: Possible Overlap in R&D Requirements of IC and MF Systems

Description: The next generation of large scale fusion devices--ITER/LMJ/NIF--will require diagnostic components to operate in environments far more severe than those encountered in present facilities. This harsh environment will be induced by fluxes of neutrons, gamma rays, energetic ions, electromagnetic radiation, and in some cases debris and shrapnel, at levels several orders of magnitude higher than those experienced in today's devices. For several years the question of possible synergy between inertia… more
Date: May 8, 2008
Creator: Bourgade, J. L.; Costley, A. E.; Reichle, R.; Hodgson, E. R.; Hsing, W.; Glebov, V. et al.
Partner: UNT Libraries Government Documents Department
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Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K

Description: A liquid hydrogen in a absorber for muon cooling requires that up to 300 W be removed from 20 liters of liquid hydrogen. The wall of the container is a heat exchanger between the hydrogen and 14 K helium gas in channels within the wall. The warm liquid hydrogen is circulated down the cylindrical walls of the absorber by free convection. The flow of the hydrogen is studied using FEA methods for two cases and the heat transfer coefficient to the wall is calculated. The first case is when the wall… more
Date: May 8, 2004
Creator: Green, Michael A.; Yang, S. W.; Green, M. A. & Lau, W.
Partner: UNT Libraries Government Documents Department
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The Search for Muon Neutrinos from Northern HemisphereGamma-Ray Bursts with AMANDA

Description: We present the results of the analysis of neutrino observations by the Antarctic Muon and Neutrino Detector Array (AMANDA) correlated with photon observations of more than 400 gamma-ray bursts (GRBs) in the Northern Hemisphere from 1997 to 2003. During this time period, AMANDA's effective collection area for muon neutrinos was larger than that of any other existing detector. Based on our observations of zero neutrinos during and immediately prior to the GRBs in the dataset, we set the most stri… more
Date: May 8, 2007
Creator: Collaboration, IceCube; Klein, Spencer & Achterberg, A.
Partner: UNT Libraries Government Documents Department
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A general scaling relation for the critical current density inNb3Sn

Description: We review the scaling relations for the critical currentdensity (Jc) in Nb3Sn wires and include recent findings on the variationof the upper critical field (Hc2) with temperature (T) and A15composition. Measurements of Hc2(T) in inevitably inhomogeneous wires, aswell as analysis of literature results, have shown that all availableHc2(T) data can be accurately described by a single relation from themicroscopic theory. This relation also holds for inhomogeneity averaged,effective, Hc2*(T) results… more
Date: May 8, 2006
Creator: Godeke, A.; Haken, B. ten; Kate, H.H.J. ten & Larbalestier, D.C.
Partner: UNT Libraries Government Documents Department
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Development of Onsite Transportation Safety Documents for Nevada Test Site

Description: Department of Energy (DOE) Orders require each DOE site to develop onsite transportation safety documents (OTSDs). The Nevada Test Site approach divided all onsite transfers into two groups with each group covered by a standalone OTSD identified as Non-Nuclear and Nuclear. The Non-Nuclear transfers involve all radioactive hazardous material in less than Hazard Category (HC)-3 quantities and all chemically hazardous materials. The Nuclear transfers involve all radioactive material equal to or gr… more
Date: May 8, 2008
Creator: Frank Hand, Willard Thomas, Frank Sciacca, Manny Negrete, Susan Kelley
Partner: UNT Libraries Government Documents Department
open access

A general scaling relation for the critical current density inNb3Sn

Description: We review the scaling relations for the critical currentdensity (Jc) in Nb3Sn wires and include recent findings on the variationof the upper critical field (Hc2) with temperature (T) and A15composition. Measurements of Hc2(T) in inevitably inhomogeneous wires, aswell as analysis of literature results, have shown that all availableHc2(T) data can be accurately described by a single relation from themicroscopic theory. This relation also holds for inhomogeneity averaged,effective, Hc2*(T) results… more
Date: May 8, 2006
Creator: Godeke, A.; Haken, B. ten; Kate, H.H.J. ten & Larbalestier, D.C.
Partner: UNT Libraries Government Documents Department
open access

Neutron Bang Time Detector Based on a Light Pipe

Description: A neutron bang time detector consisting of a scintillator, light pipe, photomultiplier tube (PMT), and high-bandwidth oscilloscope has been implemented on the 60-beam, 30-kJ OMEGA Laser Facility at the University of Rochester's Laboratory for Laser Energetics. Light from the scintillator, located 23 cm from the target, is transmitted outside the target bay through a 9.6-m-long, 2-in.-diam polished stainless steel pipe to the PMT. The PMT signal is recorded by two channels of a 6-GHz, 10-GS/s Te… more
Date: May 8, 2008
Creator: Glebov, V. Y.; Moran, M.; Stoeckl, C.; Sangster, T. C. & Cruz, M.
Partner: UNT Libraries Government Documents Department
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Bond stretching phonon softening and angle-resolved photoemission kinks in optimally doped Bi2Sr1:6La0:4Cu2O6+sigma superconductors

Description: We report the first measurement of the Cu-O bond stretching phonon dispersion in optimally doped Bi2Sr1.6La0.4Cu2O6+delta using inelastic x-ray scattering. We found a softening of this phonon at q=(0.25,0,0) from 76 to 60 meV, similar to the one reported in other cuprates. A comparison with angle-resolved photoemission data on the same sample revealed an excellent agreement in terms of energy and momentum between the angle-resolved photoemission nodal kink and the soft part of the bond stretchi… more
Date: May 8, 2008
Creator: Graf, Jeff; d'Astuto, M.; Jozwiak, C.; Garcia, D.R.; Saini, N.L.; Krisch, M. et al.
Partner: UNT Libraries Government Documents Department
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Breakdown of Electrostatic Predictions for the Nonlinear Dispersion Relation of a Stimulated Raman Scattering-Driven Plasma Wave

Description: The kinetic nonlinear dispersion relation, and frequency shift {delta}{omega}{sub srs}, of a plasma wave driven by stimulated Raman scattering (SRS) are presented. Our theoretical calculations are fully electromagnetic, and use an adiabatic expression for the electron susceptibility which accounts for the change in phase velocity as the wave grows. When k{lambda}{sub D} {approx}> 0.35 (k being the plasma wave number and {lambda}{sub D} the Debye length), {delta}{omega}{sub srs} is significan… more
Date: May 8, 2007
Creator: Benisti, D; Strozzi, D J & Gremillet, L
Partner: UNT Libraries Government Documents Department
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Experimental measurements of the 15O(alpha,gamma)19Ne reaction rate and the stability of thermonuclear burning on accreting neutron stars

Description: Neutron stars in close binary star systems often accrete matter from their companion stars. Thermonuclear ignition of the accreted material in the atmosphere of the neutron star leads to a thermonuclear explosion which is observed as an X-ray burst occurring periodically between hours and days depending on the accretion rate. The ignition conditions are characterized by a sensitive interplay between the accretion rate of the fuel supply and its depletion rate by nuclear burning in the hot CNO c… more
Date: May 8, 2007
Creator: Fisker, J.; Tan, W.; Goerres, J.; Wiescher, M. & Cooper, R.
Partner: UNT Libraries Government Documents Department
open access

Distance-Two Interpolation for Parallel Algebraic Multigrid

Description: Algebraic multigrid (AMG) is one of the most efficient and scalable parallel algorithms for solving sparse linear systems on unstructured grids. However, for large three-dimensional problems, the coarse grids that are normally used in AMG often lead to growing complexity in terms of memory use and execution time per AMG V-cycle. Sparser coarse grids, such as those obtained by the Parallel Modified Independent Set coarsening algorithm (PMIS) [7], remedy this complexity growth, but lead to non-sc… more
Date: May 8, 2007
Creator: De Sterck, H; Falgout, R; Nolting, J & Yang, U M
Partner: UNT Libraries Government Documents Department
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The Spin- and Angel-Resolved Photelectron Spectrometer

Description: A spin- and angle-resolved x-ray photoelectron spectrometer for the study of magnetic materials will be discussed. It consists of a turntable with electron lenses connected to a large hemispherical analyzer. A mini-Mott spin detector is fitted to the output of the hemispherical analyzer. This system, when coupled to a synchrotron radiation source will allow determination of a complete set of quantum numbers of a photoelectron. This instrument will be used to study ferromagnetic, antiferromagnet… more
Date: May 8, 2007
Creator: Mankey, G J; Morton, S A; Tobin, J G; Yu, S W & Waddill, G D
Partner: UNT Libraries Government Documents Department
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Electron and ion cyclotron heating calculations in the tandem-mirror modeling code MERTH

Description: To better understand and predict tandem-mirror experiments, we are building a comprehensive Mirror Equilibrium Radial Transport and Heating (MERTH) code. In this paper we first describe our method for developing the code. Then we report our plans for the installation of physics packages for electron- and ion-cyclotron heating of the plasma.
Date: May 8, 1985
Creator: Smith, G. R.
Partner: UNT Libraries Government Documents Department
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Fuel pellets and optical systems for inertially confined fusion

Description: Current laser-driven ICF targets are complex sets of concentric spherical shells made from a variety of materials including the fuel (e.g., deuterium-tritium), glass, beryllium, gold, polymeric materials, organo-metallics, and several additional organic and inorganic materials depending on the particular experiments to be done. While it is not yet known what the reactor targets will be exactly, there is little reason to believe they will be just simple, low quality glass shells containing DT ga… more
Date: May 8, 1979
Creator: Hendricks, C.D.
Partner: UNT Libraries Government Documents Department
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Mixed oxide fuel development

Description: This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to… more
Date: May 8, 1987
Creator: Leggett, R. D. & Omberg, R. P.
Partner: UNT Libraries Government Documents Department
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Role of ECRH in potential formation for tandem mirrors

Description: The axial ion plugging potential in a tandem mirror is produced by electron cyclotron resonance heating (ECRH) applied at two locations in the end mirror cell. A second harmonic (..omega.. = 2..omega../sub c/) resonance is used near the midplane to generate hot electrons which yield an electron potential barrier between center cell electrons and electrons outboard of the end cell midplane. The latter group of electrons is then heated at the fundamental resonance (..omega.. = ..omega../sub c/) o… more
Date: May 8, 1985
Creator: Rognlien, T. D.; Matsuda, Y. & Stewart, J. J.
Partner: UNT Libraries Government Documents Department
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Fusion reactor requirements and systems for energy storage and transfer

Description: Energy storage and transfer requirements for many of the present day reactor systems are listed. Two ohmic heating (OH) requirements, those for toroidal Z-pinches and Tokamaks, are described in more detail. Technologies envisioned for the power conditioning circuitry are discussed.
Date: May 8, 1978
Creator: Thomassen, K.I.; Hagenson, R.L. & Thullin, P.
Partner: UNT Libraries Government Documents Department
open access

The ACP (Advanced Computer Program) Branch bus and real-time applications of the ACP multiprocessor system

Description: The ACP Branchbus, a high speed differential bus for data movement in multiprocessing and data acquisition environments, is described. This bus was designed as the central bus in the ACP multiprocessing system. In its full implementation with 16 branches and a bus switch, it will handle data rates of 160 MByte/sec and allow reliable data transmission over inter rack distances. We also summarize applications of the ACP system in experimental data acquisition, triggering and monitoring, with spec… more
Date: May 8, 1987
Creator: Hance, R.; Areti, H.; Atac, R.; Biel, J.; Cook, A.; Fischler, M. et al.
Partner: UNT Libraries Government Documents Department
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