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Some frontiers of accelerator physics

Description: This paper discusses some concepts of future accelerators such as free electron lasers, two beam accelerator; and plasma-based adiabatic compressor. 12 refs., 10 figs., 5 tabs. (LSP)
Date: October 13, 1989
Creator: Sessler, A. M.
Partner: UNT Libraries Government Documents Department
open access

A fast large-area position-sensitive time-of-flight neutron detection system

Description: A new position-sensitive time-of-flight neutron detection and histograming system has been developed for use at the Intense Pulsed Neutron Source. Spatial resolution of roughly 1 cm {times} 1 cm and time-of-flight resolution of {approximately}1 {mu}sec are combined in a detection system which can ultimately be expanded to cover several square meters of active detector area. This system is based on the use of arrays of cylindrical one-dimensional position-sensitive proportional counters, and is … more
Date: October 13, 1989
Creator: Crawford, R.K. & Haumann, J.R.
Partner: UNT Libraries Government Documents Department
open access

Charmless Two-Body and Quasi-Two-Body B-decays at BABAR

Description: The authors present improved measurements of the branching fractions and CP asymmetries in the two-body decays B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, B{sup 0} {yields} K{sup 0}{pi}{sup 0} and B{sup 0} {yields} K{sup +}{pi}{sup -} as well as the quasi two-body B{sup 0} {yields} K{sub 1}(1270){sup +} {pi}{sup -} and B{sup 0} {yields} K{sub 1}(1400){sup +} {pi}{sup -} decays. These updated measurements are made using the complete set of BABAR data taken at the Y(4S) resonance, collected between… more
Date: October 13, 2008
Creator: Ofte, Ingrid
Partner: UNT Libraries Government Documents Department
open access

Germanium-Based Detectors for Gamma-Ray Imaging andSpectroscopy

Description: Germanium-based detectors are the standard technology usedfor gamma-ray spectroscopy when high efficiency and excellent energyresolution are desired. By dividing the electrical contacts on thesedetectors into segments, the locations of the gamma-ray interactionevents within the detectors can be determined as well as the depositedenergies. This enables simultaneous gamma-ray imaging and spectroscopyand leads to applications in the areas of astronomy, nuclear physics,environmental remediation, nu… more
Date: October 13, 2006
Creator: Amman, Mark; Luke, Paul N. & Boggs, Steven E.
Partner: UNT Libraries Government Documents Department
open access

Generation IV PR and PP Methods and Applications

Description: This paper presents an evaluation methodology for proliferation resistance and physical protection (PR&PP) of Generation IV nuclear energy systems (NESs). For a proposed NES design, the methodology defines a set of challenges, analyzes system response to these challenges, and assesses outcomes. The challenges to the NES are the threats posed by potential actors (proliferant States or sub-national adversaries). The characteristics of Generation IV systems, both technical and institutional, a… more
Date: October 13, 2008
Creator: Bari, R. A.
Partner: UNT Libraries Government Documents Department
open access

The AdS/CFT Correspondence and Light-Front QCD

Description: We identify an invariant light-front coordinate {zeta} which allows the separation of the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schroedinger equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. This frame-independent light-front wave equation is equivalent to the equations of motion whi… more
Date: October 13, 2008
Creator: Brodsky, Stanley J. & de Teramond, Guy F.
Partner: UNT Libraries Government Documents Department
open access

Alpha(phi2) From a Time-Dependent Analysis of B0 -> (rhopi)0 Dalitz-plot

Description: The authors present results of time-dependent Dalitz plot analyses of B{sup 0} {yields} ({rho}{pi}){sup 0} and the corresponding constraints on the angle {alpha} or {phi}{sub 2} of the CKM unitarity triangle from the B factories.
Date: October 13, 2008
Creator: Mohanty, G & U., Warwick
Partner: UNT Libraries Government Documents Department
open access

Computing Criticality of Lines in Power Systems

Description: We propose a computationally efficient method based onnonlinear optimization to identify critical lines, failure of which cancause severe blackouts. Our method computes criticality measure for alllines at a time, as opposed to detecting a single vulnerability,providing a global view of the system. This information on criticality oflines can be used to identify multiple contingencies by selectivelyexploring multiple combinations of broken lines. The effectiveness of ourmethod is demonstrated on … more
Date: October 13, 2006
Creator: Pinar, Ali; Reichert, Adam & Lesieutre, Bernard
Partner: UNT Libraries Government Documents Department
open access

MAXI and GLAST Studies of Jets in Active Galaxies

Description: The recent launch of GLAST--coinciding with the MAXI workshop--opens a new era for studies of jet-dominated active galaxies, known as blazars. While the emission processes operating in various spectral bands in blazars are reasonably well understood, the knowledge of the details of the structure of the jet, location of the dissipation region with respect to the accreting black hole, and coupling of the jet to the accretion process are known only at a rudimentary level. Blazars are variable, and… more
Date: October 13, 2008
Creator: Madejski, Greg; Kataoka, Jun & Sikora, Marek
Partner: UNT Libraries Government Documents Department
open access

Modeling and Experimental Investigation of Methylcyclohexane Ignition in a Rapid Compression Machine

Description: A new mechanism for the oxidation of methylcyclohexane has been developed. The mechanism combined a newly-developed low temperature mechanism with a previously developed high temperature mechanism. Predictions from the chemical kinetic model have been compared to experimentally measured ignition delay times from a rapid compression machine. Predicted ignition delay times using the initial estimates of the methylcyclohexyl peroxy radical isomerization rate constants were much longer than those m… more
Date: October 13, 2005
Creator: Pitz, W J; Naik, C V; Mhaold?in, T N; Curran, H J; Orme, J P; Simmie, J M et al.
Partner: UNT Libraries Government Documents Department
open access

Volumetric data analysis using Morse-Smale complexes

Description: The 3D Morse-Smale complex is a fundamental topological construct that partitions the domain of a real-valued function into regions having uniform gradient flow behavior. In this paper, we consider the construction and selective presentation of cells of the Morse-Smale complex and their use in the analysis and visualization of scientific datasets. We take advantage of the fact that cells of different dimension often characterize different types of features present in the data. For example, crit… more
Date: October 13, 2005
Creator: Natarajan, V & Pascucci, V
Partner: UNT Libraries Government Documents Department
open access

Structural Distortions in 5-10 Nm Silver Nanoparticles Under High Pressure

Description: We present experimental evidence that silver nanoparticles in the size range of 5-10 nm undergo a reversible structural transformation under hydrostatic pressures up to 10 GPa. We have used x-ray diffraction with a synchrotron light source to investigate pressure-dependent and size-dependent trends in the crystal structure of silver nanoparticles in a hydrostatic medium compressed in a diamond-anvil cell. Results suggest a reversible linear pressure-dependent rhombohedral distortion which has n… more
Date: October 13, 2008
Creator: Koski, Kristie J.; Kamp, Noelle M.; Kunz, Martin; Knight, Jason K.; Alivisatos, A. P. & Smith, R. K.
Partner: UNT Libraries Government Documents Department
open access

A Unified Model of Secondary Electron Cascades in Diamond

Description: In this paper we present a detailed and unified theoretical treatment of secondary electron cascades that follow the absorption of an X-ray photon. A Monte Carlo model has been constructed that treats in detail the evolution of electron cascades induced by photoelectrons and by Auger electrons following inner shell ionizations. Detailed calculations are presented for cascades initiated by electron energies between 0.1-10 keV. The present paper expands our earlier work by extending the primary e… more
Date: October 13, 2004
Creator: Ziaja, B; London, R A & Hajdu, J
Partner: UNT Libraries Government Documents Department
open access

Comment on "Paleoclassical Transport in Low-Collisionality Toroidal Plasmas"

Description: Paleoclassical transport [1] is a recently proposed fundamental process that is claimed to occur in resistive plasmas and to be missing in the collisional drift-kinetic equations (DKE) in standard use. In this Comment we raise three puzzles presented by paleoclassical transport as developed in [1], one to do with conservation and two concerning uniqueness.
Date: October 13, 2006
Creator: LoDestro, L. L.
Partner: UNT Libraries Government Documents Department
open access

After-hours Power Status of Office Equipment in the USA

Description: Office equipment is expected to be the fastest-growingsegment of commercial energy use over the next 20 years, yet many aspectsof office equipment energy use are poorly understood. User behavior, suchas turning off devices at night or enabling power management, influencesenergy use to a great extent. The computing environment also plays a roleboth in influencing user behavior and in the success of power management.Information about turn-off rates and power management rates for officeequipment w… more
Date: October 13, 2005
Creator: Webber, Carrie A.; Roberson, Judy A.; McWhinney, Marla C.; Brown,Richard E.; Pinckard, Margaret J. & Busch, John F.
Partner: UNT Libraries Government Documents Department
open access

A Strong-Lens Survey in AEGIS: the influence of large scalestructure

Description: We report on the results of a visual search for galaxy-scale strong gravitational lenses over 650 arcmin{sup 2} of HST/ACS (F606W and F814W) imaging in the DEEP2-Extended Groth Strip (EGS). In addition to a previously-known Einstein Cross also found by our search (the 'Cross', HSTJ141735+52264, z{sub lens} = 0.8106, z{sub source} = 3.40), we identify two new strong galaxy-galaxy lenses with multiple extended arcs. The first, HSTJ141820+52361 (the 'Dewdrop'; z{sub lens} = 0.5798), lenses two dis… more
Date: October 13, 2006
Creator: Moustakas, Leonidas A.; Marshall, Phil; Newman, Jeffrey A.; Coil,Alison L.; Cooper, Michael C.; Davis, Marc et al.
Partner: UNT Libraries Government Documents Department
open access

Diagnostic timing system for the TMX-Upgrade

Description: This system provides trigger signals at various times and clock signals at various frequencies for the CAMAC transient recorders of the plasma diagnostics system for the TMX-Upgrade. The timing system is designed so that all clocks are in fixed-phase relation to their corresponding triggers and to each other. Therefore, data recorded from the different diagnostics can be directly time compared. Trigger signals can be generated in 100-ns increments, with an uncertainty of 500 ps. The clock signa… more
Date: October 13, 1981
Creator: Bell, H.H. Jr.; G.W., Coutts & Hinz, A.F.
Partner: UNT Libraries Government Documents Department
open access

Immobilization of high level nuclear reactor wastes in SYNROC: a current appraisal. [Synthetic perovskite and hollandite; natural zirconolite and perovskite]

Description: Results are presented for leach testing at 95/sup 0/C and 200/sup 0/C of SYNROC containing 9% and 20% simulated high level radioactive waste, synthetic hollandite and pervoskite samples, and natural zirconolite and pervoskite samples. Single phase synthetic minerals show much higher leach rates than natural mineral samples and polyphase SYNROC samples. Natural zirconolite samples with low radiation damage have leach rates at 200/sup 0/C based on U which are identical to those measured on SYNROC… more
Date: October 13, 1981
Creator: Oversby, V.M. & Ringwood, A.E.
Partner: UNT Libraries Government Documents Department
open access

Heavy Flavor Production at Fixed Target and Collider Energies

Description: A review is presented of heavy quark production in /bar p/p, p, and pp interactions at fixed target and collider energies. Calculations of total cross sections are described including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of charm and bottom quark masses and other parameters. Open issues in the interpretation of results are summarized. A discussion is … more
Date: October 13, 1988
Creator: Berger, E. L.
Partner: UNT Libraries Government Documents Department
open access

Phenomenology of Heavy Flavor Production

Description: A review is presented of heavy quark in /bar p/p, p, and pp interactions at fixed target and collider energies. Calculations of total cross sections are described, including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of charm and bottom quark masses and other parameters. Open issues in the interpretation of results are summarized. A discussion is presented … more
Date: October 13, 1988
Creator: Berger, E. L.
Partner: UNT Libraries Government Documents Department
open access

Vacuum analysis and design for the MFTF-B Tandem Magnetic Fusion Experiment

Description: Three vacuum vessels comprise the vacuum envelope of MFTF-B. The design specifications are given for each. (MOW)
Date: October 13, 1980
Creator: Pittenger, L. C.; Bulmer, R. H.; Lane, M. A.; Margolies, D. S.; Valby, L. E. & Vepa, K.
Partner: UNT Libraries Government Documents Department
open access

Stochastic Kinetic Monte Carlo algorithms for long-range Hamiltonians

Description: We present a higher order kinetic Monte Carlo methodology suitable to model the evolution of systems in which the transition rates are non- trivial to calculate or in which Monte Carlo moves are likely to be non- productive flicker events. The second order residence time algorithm first introduced by Athenes et al.[1] is rederived from the n-fold way algorithm of Bortz et al.[2] as a fully stochastic algorithm. The second order algorithm can be dynamically called when necessary to eliminate unp… more
Date: October 13, 2003
Creator: Mason, D R; Rudd, R E & Sutton, A P
Partner: UNT Libraries Government Documents Department
open access

Structure, Stability and ELM Dynamics of the H-Mode Pedestal in DIII-D

Description: Experiments are described that have increased understanding of the transport and stability physics that set the H-mode edge pedestal width and height, determine the onset of Type-I edge localized modes (ELMs), and produce the nonlinear dynamics of the ELM perturbation in the pedestal and scrape-off layer (SOL). Predictive models now exist for the n{sub e} pedestal profile and the p{sub e} height at the onset of Type-I ELMs, and progress has been made toward predictive models of the T{sub e} ped… more
Date: October 13, 2004
Creator: Fenstermacher, M. E.; Leonard, A. W.; Osborne, T. H.; Snyder, P. B.; Thomas, D. M.; Boedo, J. A. et al.
Partner: UNT Libraries Government Documents Department
open access

The National Ignition Facility: The World's Largest Laser

Description: The National Ignition Facility (NIF), currently under construction at the 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 with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest and most energetic laser experimental system, providing an international center to study inertial confinement fusion and the physics… more
Date: October 13, 2003
Creator: Moses, E I
Partner: UNT Libraries Government Documents Department
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