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Electron Beam Lifetime in SPEAR3: Measurement and Simulation

Description: In this paper we report on electron beam lifetime measurements as a function of scraper position, RF voltage and bunch fill pattern in SPEAR3. We then outline development of an empirical, macroscopic model using the beam-loss rate equation. By identifying the dependence of loss coefficients on accelerator and beam parameters, a numerically-integrating simulator can be constructed to compute beam decay with time. In a companion paper, the simulator is used to train a parametric, non-linear dynam… more
Date: December 19, 2007
Creator: Corbett, J.; Huang, X.; Lee, M. & Lui, P.
Partner: UNT Libraries Government Documents Department
open access

Hard QCD Processes at Colliders

Description: Recent developments in the study of hard QCD processes at colliders are reviewed, in the context of the imminent startup of the LHC.
Date: December 19, 2007
Creator: Dixon, Lance J.
Partner: UNT Libraries Government Documents Department
open access

Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States

Description: The authors present a search for the decays B{sup 0} {yields} e{sup +}e{sup -}, B{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}} using data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. Using a dataset corresponding to 384 x 10{sup 6} B{bar B} pairs, they do not find evidence of any of the three decay modes. They obtain upper limit on the branching fractions, at 90% confidence level, of {Beta}(B{sup 0} {yields} e{sup +… more
Date: December 19, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

Status of DAFNE

Description: DA{Phi}NE is a double ring electron-positron collider, designed to provide very high luminosity at the energy of the {Phi} resonance (1.02 GeV c.m.). After storing the first beam in fall 1997, the collider was commissioned without solenoidal detectors until the end of 1998, reaching a single bunch luminosity of 1.6 x 10{sup 30} cm{sup -2}s{sup -1} with 20 mA in each beam, corresponding to a beam-beam tune shift of {approx} 0.03. A longitudinal bunch-to-bunch feedback has been implemented, allow… more
Date: December 19, 2007
Creator: Preger, M.; /Frascati; Alesini, D.; Benedetti, G.; Bertolucci, S.; Biscari, C. et al.
Partner: UNT Libraries Government Documents Department
open access

Formal Specification of the OpenMP Memory Model

Description: OpenMP [2] is an important API for shared memory programming, combining shared memory's potential for performance with a simple programming interface. Unfortunately, OpenMP lacks a critical tool for demonstrating whether programs are correct: a formal memory model. Instead, the current official definition of the OpenMP memory model (the OpenMP 2.5 specification [2]) is in terms of informal prose. As a result, it is impossible to verify OpenMP applications formally since the prose does not provi… more
Date: December 19, 2006
Creator: Bronevetsky, G & de Supinski, B
Partner: UNT Libraries Government Documents Department
open access

On-chip single-copy real-time reverse-transcription PCR in isolated picoliter droplets

Description: The first lab-on-chip system for picoliter droplet generation and RNA isolation, followed by reverse transcription, and PCR amplification with real-time fluorescence detection in the trapped droplets has been developed. The system utilized a shearing T-junction in a fused silica device to generate a stream of monodisperse picoliter-scale droplets that were isolated from the microfluidic channel walls and each other by the oil phase carrier. An off-chip valving system stopped the droplets on-chi… more
Date: December 19, 2007
Creator: Beer, N. R.; Wheeler, E.; Lee-Houghton, L.; Watkins, N.; Nasarabadi, S.; Hebert, N. et al.
Partner: UNT Libraries Government Documents Department
open access

DIRECT MEASUREMENT OF HEAT FLUX FROM COOLING LAKE THERMAL IMAGERY

Description: Laboratory experiments show a linear relationship between the total heat flux from a water surface to air and the standard deviation of the surface temperature field, {sigma}, derived from thermal images of the water surface over a range of heat fluxes from 400 to 1800 Wm{sup -2}. Thermal imagery and surface data were collected at two power plant cooling lakes to determine if the laboratory relationship between heat flux and {sigma} exists in large heated bodies of water. The heat fluxes comput… more
Date: December 19, 2007
Creator: Garrett, A; Eliel Villa-Aleman, E; Robert Kurzeja, R; Malcolm Pendergast, M; Timothy Brown, T & Saleem Salaymeh, S
Partner: UNT Libraries Government Documents Department
open access

General Features of Supersymmetric Signals at the ILC: Solving the LHC Inverse Problem

Description: We examine whether the {radical}s = 500 GeV International Linear Collider with 80% electron beam polarization can be used to solve the LHC Inverse Problem within the framework of the MSSM. We investigate 242 points in the MSSM parameter space, which we term models, that correspond to the 162 pairs of models found by Arkani-Hamed et al. to give indistinguishable signatures at the LHC. We first determine whether the production of the various SUSY particles is visible above the Standard Model back… more
Date: December 19, 2007
Creator: Berger, Carola F.; Gainer, James S.; Hewett, JoAnne L.; Lillie, Ben & Rizzo, Thomas G.
Partner: UNT Libraries Government Documents Department
open access

Is there a hard gluonic contribution to the first moment of g sub 1

Description: We show that the size of the hard gluonic contribution to the first moment of the proton's spin-dependent structure function g{sub 1} is entirely a matter of the convention used in defining the quark distributions. If the UV regulator for the spin-dependent quark distributions respects the gauge invariance of Green's functions (allows shifts of loop momenta) and respects the analyticity structure of the unregulated distributions, then the hard gluonic contribution to the first moment of g{sub 1… more
Date: December 19, 1990
Creator: Bodwin, G.T. (Argonne National Lab., IL (USA)) & Qiu, Jianwei (State Univ. of New York, Stony Brook, NY (USA). Inst. for Theoretical Physics)
Partner: UNT Libraries Government Documents Department
open access

Attitude control of a spinning rocket via thrust vectoring

Description: Two controllers are developed to provide attitude control of a spinning rocket that has a thrust vectoring capability. The first controller has a single-input/single-output design that ignores the gyroscopic coupling between the control channels. The second controller has a multi-input/multi-output structure that is specifically intended to account for the gyroscopic coupling effects. A performance comparison between the two approached is conducted for a range of roll rates. Each controller is … more
Date: December 19, 1990
Creator: White, J.E.
Partner: UNT Libraries Government Documents Department
open access

A Search for Massive Compact Halo Objects in Our Galaxy

Description: MAssive Compact Halo Objects such as brown dwarfs, Jupiters, and black holes are prime candidates to comprise the dark halo of our galaxy. Paczynski noted that these objects (dubbed MACHOs) can be detected via gravitational microlensing of stars in the Magellanic Clouds with the caveat that only about one in 10{sup 6} stars will be lensed at any given time. Our group is currently involved in constructing a dedicated observing system at the Mount Stromlo Observatory in Australia. We will use a r… more
Date: December 19, 1990
Creator: Alock, C.; Axelrod, T.; Cook, K.; Park, H. (Lawrence Livermore National Lab., CA (USA)); Griest, K.; Stubbs, C. (California Univ., Berkeley, CA (USA). Center for Particle Astrophysics) et al.
Partner: UNT Libraries Government Documents Department
open access

30+ years of plasma simulation

Description: No Description Available.
Date: December 19, 1990
Creator: Langdon, B.
Partner: UNT Libraries Government Documents Department
open access

Optical, UV, and EUV Oscillations of SS Cygni in Outburst

Description: I provide a review of observations in the optical, UV (HST), and EUV (EUVE and Chandra LETG) of the rapid periodic oscillations of nonmagnetic, disk-accreting, high mass-accretion rate cataclysmic variables (CVs), with particular emphasis on the dwarf nova SS Cyg in outburst. In addition, I drawn attention to a correlation, valid over nearly six orders of magnitude in frequency, between the frequencies of the quasi-periodic oscillations (QPOs) of white dwarf, neutron star, and black hole binari… more
Date: December 19, 2003
Creator: Mauche, C W
Partner: UNT Libraries Government Documents Department
open access

Flame Inhibition by Phosphorus-Containing Compounds in Lean and Rich Propane Flames

Description: Chemical inhibition of laminar propane flames by organophosphorus compounds has been studied experimentally, using a laboratory Mache Hebra nozzle burner and a flat flame burner with molecular beam mass spectrometry (MBMS), and with a computational flame model using a detailed chemical kinetic reaction mechanism. Both fuel-lean and fuel-rich propane flames were studied to examine the role of equivalence ratio in flame inhibition. The experiments examined a wide variety of organophosphorus compo… more
Date: December 19, 2003
Creator: Curran, H; Korobeinichev, O P; Shvartsberg, V M; Shmakov, A G; Bolshova, T A; Jayaweera, T M et al.
Partner: UNT Libraries Government Documents Department
open access

Geotechnical Assessment and Instrumentation Needs for Nuclear Waste Isolation in Crystalline and Argillaceous Rocks Symposium

Description: Today there exists in the United States a large volume of nuclear wastes that result from both military and commercial activities. The United States has to date placed major emphasis on disposal in only one rock type--salt--whereas other nations have considered other rock types, such as granite in England and Sweden and clays in Belgium. No comprehensive evaluation of isolation in rocks other than salt has been made in the United States, and it is most appropriate that other rock types be evalu… more
Date: December 19, 1978
Creator: Authors, Various
Partner: UNT Libraries Government Documents Department
open access

SAVANNAH RIVER SITE TANK 18 AND TANK 19 WALL SAMPLER PERFORMANCE

Description: A sampling tool was required to evaluate residual activity ({mu}Curies per square foot) on the inner wall surfaces of underground nuclear waste storage tanks. The tool was required to collect a small sample from the 3/8 inch thick tank walls. This paper documents the design, testing, and deployment of the remotely operated sampling device. The sampler provides material from a known surface area to estimate the overall surface contamination in the tank prior to closure. The sampler consisted of … more
Date: December 19, 2009
Creator: Leishear, R.; Thaxton, D.; Minichan, R.; France, T.; Steeper, T.; Corbett, J. et al.
Partner: UNT Libraries Government Documents Department
open access

3D GRMHD and GRPIC Simulations of Disk-Jet Coupling and Emission

Description: We investigate jet formation in black-hole systems using 3-D General Relativistic Particle-In-Cell (GRPIC) and 3-D GRMHD simulations. GRPIC simulations, which allow charge separations in a collisionless plasma, do not need to invoke the frozen condition as in GRMHD simulations. 3-D GRPIC simulations show that jets are launched from Kerr black holes as in 3-D GRMHD simulations, but jet formation in the two cases may not be identical. Comparative study of black hole systems with GRPIC and GRMHD s… more
Date: December 19, 2006
Creator: Nishikawa, Ken-Ichi; Mizuno, Y.; Watson, M.; Hardee, P.; Fuerst, S.; Wu, K. et al.
Partner: UNT Libraries Government Documents Department
open access

Opportunities in Plutonium Metallurgical Research

Description: This is an exciting time to be involved in plutonium metallurgical research. Over the past few years, there have been significant advances in our understanding of the fundamental materials science of this unusual metal, particularly in the areas of self-irradiation induced aging of Pu, the equilibrium phase diagram, the homogenization of {delta}-phase alloys, the crystallography and morphology of the {alpha}{prime}-phase resulting from the isothermal martensitic phase transformation, and the ph… more
Date: December 19, 2006
Creator: Schwartz, A J
Partner: UNT Libraries Government Documents Department
open access

FEDERAL USERS CONFERENCE PRODUCT LINE TOOL SET (PLTS) MAP PRODUCTION SYSTEM (MPS) ATLAS CUSTOM GRIDS [Rev 0 was draft]

Description: Maps, and more importantly Atlases, are assisting the user community in managing a large land area with complex issues, the most complex of which is the management of nuclear waste. The techniques and experiences discussed herein were gained while developing several atlases for use at the US Department of Energy's Hanford Site. The user community requires the ability to locate not only waste sites, but other features as well. Finding a specific waste site on a map and in the field is a difficul… more
Date: December 19, 2006
Creator: Hayenga, J. L.
Partner: UNT Libraries Government Documents Department
open access

Reduced-Temperature Transient-Liquid-Phase Bonding of AluminaUsing a Ag-Cu-Based Brazing Alloy

Description: The mechanical properties and microstructural evolution ofmetal-ceramic bonds produced using a transient liquid phase (TLP) aredescribed. Alumina (Al2O3) was joined at 500 degrees C, 600 degrees C,and 700 degrees C using a multilayer In/Cusil-ABA (R) (commercialcopper-silver eutectic brazing alloy)/In interlayer. The introduction ofthin In cladding layers allows the system to bond at much lowertemperatures than those typically used for brazing with Cusil-ABA (R),thereby protecting temperature-s… more
Date: December 19, 2005
Creator: Hong, Sung Moo & Glaeser, Andreas M.
Partner: UNT Libraries Government Documents Department
open access

Clean Assembly Practices to Prevent Contamination and Damage to Optics

Description: A key lesson learned from the earliest optics installed in the National Ignition Facility (NIF) was that the traditional approach for maintaining cleanliness, such as the use of cleanrooms and associated garments and protocols, is inadequate. Assembly activities often negate the benefits provided by cleanrooms, and in fact generate contamination with high damage potential. As a result, NIF introduced ''clean assembly protocols'' and related practices to supplement the traditional clean room pro… more
Date: December 19, 2005
Creator: Pryatel, J & Gourdin, W H
Partner: UNT Libraries Government Documents Department
open access

Search for the Rare Quark-annihilation Decays B->Ds(*)Phi

Description: We report on searches for B{sup -} {yields} D{sub s}{sup -} {phi} and B{sup -} {yields} D*{sub s}{sup -} {phi}. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and {bar u} quarks in the B{sup -} meson. Our results are based on 234 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limi… more
Date: December 19, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department
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