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A P-Carbon CNI Polarimeter for RHIC.

Description: The RHIC spin program requires excellent polarimetry so that the knowledge of the beam polarization does not limit the errors on the experimental measurements. However, polarimetry of proton beams with energies higher than about 30GeV poses a difficult challenge. For polarization monitoring during operation, a fast and reliable polarimeter is required that produces a polarization measurement with a 10% relative error within a few minutes. The p-Carbon elastic scattering in the Coulomb-Nuclear-S… more
Date: March 29, 1999
Creator: Huang, H.; Bai, M.; Bunce, G.; Makdisi, Y.; Roser, T.; Imai, K. et al.
Partner: UNT Libraries Government Documents Department
open access

Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty

Description: These proceedings contain papers prepared for the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear-Test-Ban Treaty, held 21-24 September 1999 in Las Vegas, Nevada. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), the Comprehensive … more
Date: September 21, 1999
Creator: Warren, N. Jill
Partner: UNT Libraries Government Documents Department
open access

Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

Description: A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreemen… more
Date: May 1, 1999
Creator: Telschow, Kenneth Louis; Deason, Vance Albert & Datta, S.K.
Partner: UNT Libraries Government Documents Department
open access

Tensor Analyzing Powers for Quasi-Elastic Electron Scattering from Deuterium

Description: We report on a first measurement of tensor analyzing powers in quasi-elastic electron-deuteron scattering at an average three-momentum transfer of 1.7 fm{sup -1}. Data sensitive to the spin-dependent nucleon density in the deuteron were obtained for missing momenta up to 150 MeV/c with a tensor polarized {sup 2}H target internal to an electron storage ring. The data are well described by a calculation that includes the effects of final-state interaction, meson-exchange and isobar currents, and … more
Date: January 1, 1999
Creator: Zhou, Z.-L.; Bouwhuis, M.; Ferro-Luzzi, M.; Passchier, E.; Alarcon, R.; Anghinolfi, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Laser modulated scattering as a nondestructive evaluation tool for optical surfaces and thin film coatings

Description: Laser modulated scattering (LMS) is introduced as a non-destructive evaluation tool for defect inspection and characterization of optical surfaces and thin film coatings. This technique is a scatter sensitive version of the well-known photothermal microscopy (PTM) technique. It allows simultaneous measurement of the DC and AC scattering signals of a probe laser beam from an optical surface. By comparison between the DC and AC scattering signals, one can differentiate absorptive defects from non… more
Date: December 22, 1999
Creator: Feit, M D; Kozlowski, M R; Rubenchik, A M; Sheehan, L & Wu, Z L
Partner: UNT Libraries Government Documents Department
open access

Final state interaction phase in B decays

Description: From an estimate of the meson-meson inelastic scattering at 5 GeV it is concluded that a typical strong phase in B decays to two mesons is of order of 20{sup o}. For a particular final state an estimate of the phase depends on whether that state is more or less probable as a final state compared to those states to which it is connected by the strong interaction S matrix.
Date: March 24, 1999
Creator: Suzuki, Mahiko & Wolfenstein, Lincoln
Partner: UNT Libraries Government Documents Department
open access

Angular Dependence of 3 Omega 0/2 Spectra from Laser-produced Plasmas

Description: Scattered light at three-halves of the incident laser frequency from solid targets is observed at five different angles. When the incident laser intensity is low enough, rescattering of two plasmon decay (TPD) instability electron plasma waves by ion acoustic waves is not significant. In this regime, Thomson scattering measurements of the electron temperature and the plasma flow velocity allow quantitative comparison of the angular dependence of the spectrum to theory.
Date: August 25, 1999
Creator: Young, P.E.; Moody, J.D. & Rhizomes, W.
Partner: UNT Libraries Government Documents Department
open access

Optical Constants of Beryllium from Photoabsorption Measurements for X-Ray Optics Applications

Description: Beryllium (Be) has been recently receiving considerable attention as the key material for a range of potential applications in the extreme ultraviolet (EUV) and x-ray region. Most notably, it has been successfully implemented as the spacer material in beryllium-based multilayer mirrors for EUV lithography, achieving experimental reflectivities of about 70% at wavelengths around 11.4 nm. Knowledge of the absorptive and dispersive properties of this material thus becomes important for the modelin… more
Date: September 30, 1999
Creator: Soufli, R.; Bajt, S. & Gullikson, E.M.
Partner: UNT Libraries Government Documents Department
open access

FINAL REPORT ''Superconducting Materials''. January 1,1996 to March 31, 2000

Description: Our theory group has discovered a mechanism for unconventional electron interaction effects in high-temperature superconductors. Electron collisions for selected structures provide an explanation for the observed neutron scattering data on high-temperature superconductors. Our University of Virginia team suggested that the observed magnetic susceptibility in copper oxide superconductors should also be seen in chromium and the metallic antiferromagnet V{sub 2}O{sub 3}, and neutron scattering exp… more
Date: April 10, 1999
Creator: Ruvalds, John
Partner: UNT Libraries Government Documents Department
open access

High Accuracy, High Energy He-Erd Analysis of H,C, and T

Description: A new analysis technique using high-energy helium ions for the simultaneous elastic recoil detection of all three hydrogen isotopes in metal hydride systems extending to depths of several {micro}m's is presented. Analysis shows that it is possible to separate each hydrogen isotope in a heavy matrix such as erbium to depths of 5 {micro}m using incident 11.48MeV {sup 4}He{sup 2} ions with a detection system composed of a range foil and {Delta}E-E telescope detector. Newly measured cross sections … more
Date: July 22, 1999
Creator: Browning, James F.; Langley, Robert A.; Doyle, Barney L.; Banks, James C. & Wampler, William R.
Partner: UNT Libraries Government Documents Department
open access

Characterization of Russian ballistic furnace shells

Description: The authors received another batch of polystyrene ballistic furnace shells on December 4, 1998. Assigned the batch number of LSC012, it consisted of three cassettes containing 36 shells in each cassette. A group of 27 of the shells were selected for characterization that ranged in diameter from 1880 to 1780 {micro}m. There were two shells with a diameter above 1900 {micro}m, but they were too fragile and did not survive initial handling. For characterization, they examined the shells through a … more
Date: February 18, 1999
Creator: Fearon, E
Partner: UNT Libraries Government Documents Department
open access

Spherical Harmonic Solutions to the 3D Kobayashi Benchmark Suite

Description: Spherical harmonic solutions of order 5, 9 and 21 on spatial grids containing up to 3.3 million cells are presented for the Kobayashi benchmark suite. This suite of three problems with simple geometry of pure absorber with large void region was proposed by Professor Kobayashi at an OECD/NEA meeting in 1996. Each of the three problems contains a source, a void and a shield region. Problem 1 can best be described as a box in a box problem, where a source region is surrounded by a square void regi… more
Date: December 29, 1999
Creator: Brown, P.N.; Chang, B. & Hanebutte, U.R.
Partner: UNT Libraries Government Documents Department
open access

Suppression of Impurity Back Scattering in Double Quantum Wires: Theory Beyond the Born Approximation

Description: The effect of higher-order corrections to the Born approximation is studied for the previously obtained giant conductance enhancement in tunnel-coupled double quantum wires in a parallel magnetic field. The relative correction is found to be significant and depends on various effects such as the magnetic field, electron and impurity densities, impurity positions, symmetric and asymmetric doping profiles, and center barrier thickness.
Date: August 9, 1999
Creator: Huang, Danhong & Lyo, S.K.
Partner: UNT Libraries Government Documents Department
open access

A transport-based condensed history algorithm

Description: Condensed history algorithms are approximate electron transport Monte Carlo methods in which the cumulative effects of multiple collisions are modeled in a single step of (user-specified) path length s{sub 0}. This path length is the distance each Monte Carlo electron travels between collisions. Current condensed history techniques utilize a splitting routine over the range 0 {le} s {le} s{sub 0}. For example, the PEnELOPE method splits each step into two substeps; one with length {xi}s{sub 0} … more
Date: January 6, 1999
Creator: Tolar Jr, D R
Partner: UNT Libraries Government Documents Department
open access

Self-Adjoint Angular Flux Equation for Coupled Electron-Photon Transport

Description: Recently, Morel and McGhee described an alternate second-order form of the transport equation called the self adjoint angular flux (SAAF) equation that has the angular flux as its unknown. The SAAF formulation has all the advantages of the traditional even- and odd-parity self-adjoint equations, with the added advantages that it yields the full angular flux when it is numerically solved, it is significantly easier to implement reflective and reflective-like boundary conditions, and in the appro… more
Date: July 8, 1999
Creator: Liscum-Powell, J. L.; Lorence, L. J., Jr.; Morel, J. E. & Prinja, A. K.
Partner: UNT Libraries Government Documents Department
open access

Quantitative Analysis with Heavy Ion E-TOF ERD

Description: Heavy ion TOF ERD combined with energy detection (E-TOF-ERD) is a powerful analytical technique taking advantage of the following facts: the scattering cross section is usually very high ({approximately}10{sup {minus}21} cm{sup 2}/sr) compared to regular He RBS ({approximately}10{sup {minus}25} cm{sup 2}/sr), contrary to what happens with the energy resolution in ordinary surface solid barrier detectors, time resolution is almost independent of the atomic mass of the detected element, and the d… more
Date: July 23, 1999
Creator: Banks, J.C.; Doyle, B.L. & Font, A. Climent
Partner: UNT Libraries Government Documents Department
open access

Observation of Secondary Plasma Waves in Laser-Plasma Interaction Experiments

Description: An experiment is described where the two products of the Langmuir Decay Instability (LDI) of a primary electron plasma wave have been observed and identified without any ambiguity. Primary Langmuir waves are driven by Stimulated Raman Scattering (SRS) of an incident laser which provides well-defined electron plasma waves. Thomson scattering of a short wavelength probe beam yields measurements of the amplitude of the waves resolved in time, space, wavelength and wavevector, that allow identifica… more
Date: December 8, 1999
Creator: Depierreux, S.; Labaune, C.; Baldis, H. A.; Fuchs, J. & Michard, A.
Partner: UNT Libraries Government Documents Department
open access

Probing coal reactivity by time-resolved small angle x-ray scattering.

Description: The objective of this study is to observe changes in coal structure in situ with small angle X-ray scattering (SAXS) during solvent swelling and during pyrolysis. We have built a SAXS instrument at the Basic Energy Sciences Synchrotrons Research Center at the Advanced Photon Source that allows us to obtain scattering patterns in the millisecond time domain. The eight Argonne Premium Coal samples were used in this study. The information that can be derived from these experiments, such as changes… more
Date: January 22, 1999
Creator: Winans, R. E.
Partner: UNT Libraries Government Documents Department
open access

Simulation of Experimental Background using FLUKA

Description: In November 1997, Experiment T423 began acquiring data with the intentions of understanding the energy spectra of high-energy neutrons generated in the interaction of electrons with lead. The following describes a series of FLUKA simulations studying (1) particle yields in the absence of all background; (2) the background caused from scattering in the room; (3) the effects of the thick lead shielding which surrounded the detector; (4) the sources of neutron background created in this lead shiel… more
Date: May 11, 1999
Creator: Rokni, Sayed
Partner: UNT Libraries Government Documents Department
open access

{gamma}{gamma} {r_arrow} {gamma}{gamma} as a Test of Weak Scale Quantum Gravity at the NLC

Description: Recently, it has been proposed that the fundamental scale of quantum gravity can be close to the weak scale if there are large extra dimensions . This proposal has important phenomenological implications for processes at the TeV scale. We study the process {gamma}{gamma} {r_arrow} {gamma}{gamma}, assuming an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory. We find that, at center of mass energies {radical}s {approximately} 1 TeV, the contribution of gravitatio… more
Date: April 23, 1999
Creator: Davoudiasl, Hooman
Partner: UNT Libraries Government Documents Department
open access

Beam-Cavity Interaction Circuit at W-Band

Description: We describe the design, fabrication and bench-study of a mm-wave cavity employed as a relativistic klystron output structure. The OFE copper cavity was prepared by electro-discharge machining and diffusion bonding, cleaned, and tuned to 91.4 GHz. Measured cavity characteristics are presented and compared with theory, including quality factor, Q, coupling parameter {beta}, scattering matrix S{sub 11}, and axial electric field profile E{sub z}. This work provides the basis for understanding of th… more
Date: July 14, 1999
Creator: Hill, Marc E
Partner: UNT Libraries Government Documents Department
open access

INEL5-single-crystal chopper spectrometer-reference instrument WBS 1.7.12.

Description: INEL5 is designed for the study of relatively high energy cooperative excitations in single crystals. Figure 1 provides a schematic representation of INEL5, and Table 1 gives the parameters for this instrument. The use of linear position sensitive detectors provides good vector Q resolution, and the coverage of a large solid angle at low scattering angles permits sampling of the necessary regions of reciprocal space to follow the dispersion of these excitations. The instrument is optimized for … more
Date: January 18, 1999
Creator: Crawford, R.K.
Partner: UNT Libraries Government Documents Department
open access

Estimating Attributes of Nuclear Weapon and Other Fissile Material Configuration Using Features Of Nuclear Materials Identification Signatures

Description: This brief describes a strategy that, when implemented, will allow the attributes, i.e., the physical properties, of nuclear weapon and other configurations of fissile material to be estimated from Nuclear Material Identification System (NMIS) signatures for arms control, treaty verification, and transparency purposes. Attributes are estimated by condensing measured NMIS signatures into ''features'' that approximately represent physical characteristics of the measurement suc… more
Date: August 24, 1999
Creator: Mattingly, J. K.; Mihalczo, J. T.; Mullens, J. A.; Perez, R. B. & Valentine, T. E.
Partner: UNT Libraries Government Documents Department
open access

Precise tests of x-ray scattering theories in the Compton regime.

Description: The authors report two experiments intended to test the accuracy of state-of-the-art theoretical predictions for x-ray scattering from low-Z atoms. The first one deals with the differential x-ray scattering cross sections in Ne and He from 11-22 keV and the Ne Compton-to-Rayleigh scattering ratio in this energy range. It was found that, in order to be consistent with the experimental results, an accurate description at low Z must include nonlocal exchange, electron correlation, and dynamic effe… more
Date: January 15, 1999
Creator: Dunford, R. W.; Gemmell, D. S.; Kanter, E. P.; Krassig, B.; Southworth, S. H. & Young, L.
Partner: UNT Libraries Government Documents Department
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