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Soft X-ray Mirrors for the Linac Coherent Light Source

Description: The Linac Coherent Light Source (LCLS) is a 0.15-1.5 nm wavelength free-electron laser (FEL) being constructed at the Stanford Linear Accelerator Center (SLAC) by a multi-institution consortium, including Lawrence Livermore National Laboratory (LLNL). One of LLNL's responsibilities involves the design and construction of two grazing-incidence mirror systems whose primary intent is to reduce radiation levels in the experimental halls by separating the FEL beam from unwanted high-energy photons. … more
Date: August 13, 2007
Creator: Pivovaroff, M. J.; Bionta, R. M.; Mccarville, T. J.; Soufli, R. & Stefan, P. M.
Partner: UNT Libraries Government Documents Department
open access

Intrinsic and Extrinsic Chemical and Isotopic Tracers for Characterization Of Groundwater Systems

Description: In many regions, three dimensional characterization of the groundwater regime is limited by coarse well spacing or borehole lithologic logs of low quality. However, regulatory requirements for drinking water or site remediation may require collection of extensive chemical and water quality data from existing wells. Similarly, for wells installed in the distant past, lithologic logs may not be available, but the wells can be sampled for chemical and isotopic constituents. In these situations, a … more
Date: September 13, 2007
Creator: Moran, J E; Singleton, M J; Carle, S F & Esser, B K
Partner: UNT Libraries Government Documents Department
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Micropatterning of Gold Substrates Based on Poly(Propylene Sulfide-Bl-Ethylene Glycol), (Pps-Peg) Background Passivation and the Molecular-Assembly Patterning by Lift-Off (Mapl) Technique

Description: Poly(propylene sulfide-bl-ethylene glycol) (PPS-PEG) is an amphiphilic block copolymer that spontaneously adsorbs onto gold from solution. This results in the formation of a stable polymeric layer that renders the surface protein resistant when an appropriate architecture is chosen. The established molecular assembly patterning by lift-off (MAPL) technique can convert a prestructured resist film into a pattern of biointeractive chemistry and a noninteractive background. Employing the MAPL techn… more
Date: November 13, 2007
Creator: Feller, L.; Bearinger, J. P.; Wu, L.; Hubbell, J. A.; Textor, M. & Tosatti, S.
Partner: UNT Libraries Government Documents Department
open access

Machine-Detector Interface Issues for the ILCPolarimeters

Description: This note examines several Machine-Detector Interface (MDI) issues for the Compton polarimeters in the Beam Delivery System of the International Linear Collider (ILC), including (1) alignment tolerances, (2) impact of crossing angle and IR magnets on spin alignment, (3) Z-pole operation, and (4) costs and conventional facilities.
Date: June 13, 2008
Creator: Woods, Mike
Partner: UNT Libraries Government Documents Department
open access

CeBr3 as a High-Resolution Gamma-Ray Detector

Description: Lanthanum halide (LaBr3:Ce) scintillators have been well-documented as high-resolution gamma-ray detectors that are operated at room temperature. These scintillators have better resolution (<3% at 662 keV) relative to sodium iodide (NaI(Tl)) scintillators (7% at 662 keV), but the naturally occurring radioactive isotope 138La causes self-activity in the crystal that occludes portions of the gamma-ray spectrum. This selfactivity limits the use of LaBr3:Ce in high-sensitivity applications. Cerium,… more
Date: November 13, 2008
Creator: Michael Reed, Paul Guss, Christopher Contreras
Partner: UNT Libraries Government Documents Department
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SHOCK INITIATION EXPERIMENTS ON PBX 9501 EXPLOSIVE AT PRESSURES BELOW 3 GPa WITH ASSOCIATED IGNITION AND GROWTH MODELING

Description: Shock initiation experiments on the explosive PBX 9501 (95% HMX, 2.5% estane, and 2.5% nitroplasticizer by weight) were performed at pressures below 3 GPa to obtain in-situ pressure gauge data, run-distance-to-detonation thresholds, and Ignition and Growth modeling parameters. Propellant driven gas guns (101 mm and 155 mm) were utilized to initiate the PBX 9501 explosive with manganin piezoresistive pressure gauge packages placed between sample slices. The run-distance-to-detonation points on t… more
Date: June 13, 2007
Creator: Chidester, S K; Thompson, D G; Vandersall, K S; Idar, D J; Tarver, C M; Garcia, F et al.
Partner: UNT Libraries Government Documents Department
open access

DYNAMIC LOADING OF TEFLON AT 200?C

Description: Dynamic loading experiments were performed on inert Teflon (Polytetrafluoroethylene) samples, initially heated to the temperature of 200 C, to test its behavior under these conditions for its use in other heated experiments. Tests were performed in the 100 mm diameter bore propellant driven gas gun with piezo-resistive manganin pressure gauges imbedded into the samples to measure loading pressures. Experimental data provided new information on the shock velocity - particle velocity relationship… more
Date: June 13, 2007
Creator: Urtiew, P A; Forbes, J W; Tarver, C M; Vandersall, K S & Garcia, F
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

Editorial

Description: The Tenth International Conference on Accelerator Mass Spectrometry (AMS-10) was held from September 5-10 at the University of California, Berkeley campus. The conference attracted 305 attendees from 26 countries who gave 144 platform presentations and presented a total of 170 posters. The conference opened with a special tribute to the late Roy Middleton, which was followed by a companion session on 'ion sourcery'. A plenary talk by Wally Broecker on his '53 years in the Radiocarbon Trenches',… more
Date: August 13, 2007
Creator: Knezovich, J; Brown, T; Buchholz, B; Finkel, B; Guilderson, T; Kashgarian, M et al.
Partner: UNT Libraries Government Documents Department
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Beam Based Measurements for Stochastic Cooling Systems at Fermilab

Description: Improvement of antiproton stacking rates has been pursued for the last twenty years at Fermilab. The last twelve months have been dedicated to improving the computer model of the Stacktail system. The production of antiprotons encompasses the use of the entire accelerator chain with the exception of the Tevatron. In the Antiproton Source two storage rings, the Debuncher and Accumulator are responsible for the accumulation of antiprotons in quantities that can exceed 2 x 10{sup 12}, but more rou… more
Date: September 13, 2007
Creator: Lebedev, V. A.; Pasquinelli, R. J. & Werkema, S. J.
Partner: UNT Libraries Government Documents Department
open access

Nanofiltration of Electrolyte Solutions by Sub-2nm Carbon Nanotube Membranes

Description: Both MD simulations and experimental studies have shown that liquid and gas flow through carbon nanotubes with nanometer size diameter is exceptionally fast. For applications in separation technology, selectivity is required together with fast flow. In this work, we use pressure-driven filtration experiments to study ion exclusion in silicon nitride/sub-2-nm CNT composite membranes as a function of solution ionic strength, pH, and ion valence. We show that carbon nanotube membranes exhibit sign… more
Date: March 13, 2008
Creator: Fornasiero, F.; Park, H. G.; Holt, J. K.; Stadermann, M.; Kim, S.; In, J. B. et al.
Partner: UNT Libraries Government Documents Department
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The US Support Program to IAEA Safeguards Priority of Containment and Surveillance

Description: The United States Support Program (USSP) priority for containment and surveillance (US) focuses on maintaining or improving the reliability and cost-effectiveness of C/S systems for IAEA safeguards, expanding the number of systems that are unattended and remotely monitored, and developing verification methods that help streamline the on-site inspection process. Existing IAEA C/S systems have evolved to become complex, integrated systems, which may include active seals, nondestructive assay (NDA… more
Date: June 13, 2008
Creator: Diaz,R.A.
Partner: UNT Libraries Government Documents Department
open access

Electrostatic Modeling of Vacuum Insulator Triple Junctions

Description: A comprehensive matrix of 60 tests was designed to explore the effect of calcium chloride vs. sodium chloride and the ratio R of nitrate concentration over chloride concentration on the repassivation potential of Alloy 22. Tests were conducted using the cyclic potentiodynamic polarization (CPP) technique at 75 C and at 90 C. Results show that at a ratio R of 0.18 and higher nitrate was able to inhibit the crevice corrosion in Alloy 22 induced by chloride. Current results fail to show in a consi… more
Date: August 13, 2007
Creator: Tully, L. K.; White, A. D.; Goerz, D. A.; Javedani, J. B. & Houck, T. L.
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&amp;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

REMOTELY RECHARGEABLE EPD

Description: Radiation measurements inside the Contact Decon Maintenance Cell (CDMC) in the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) are required to determine stay times for personnel. A system to remotely recharge the transmitter of an Electronic Personnel Dosimeter (EPD) and bail assembly to transport the EPD within the CDMC was developed by the Savannah River National Laboratory (SRNL) to address this need.
Date: November 13, 2007
Creator: Vrettos, N; Athneal Marzolf, A & Scott Bowser, S
Partner: UNT Libraries Government Documents Department
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Creep Testing Plastic-Bonded Explosives in Uni-axial Compression

Description: High fidelity measurements of time-dependent strain in the plastic-bonded explosives LX-17-1 and PBX 9502 have been performed under constant, uni-axial, compressive load using a custom designed apparatus. The apparatus uses a combination of extensometers and linear variable differential transformers coupled with a data acquisition system, thermal controls, and gravitational loading. The materials being tested consist of a crystalline explosive material mixed with a polymeric binder. The behavio… more
Date: March 13, 2008
Creator: Gagliardi, F J & Cunningham, B J
Partner: UNT Libraries Government Documents Department
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The U.S. Support Program to IAEA Safeguards - Destructive Analysis

Description: The U.S. Support Program (USSP) to IAEA Safeguards priority of destructive analysis is aimed at strengthening the IAEA's ability to use destructive analysis as a safeguards tool. IAEA inspectors bring back nuclear and environmental samples from inspections, which are first cataloged by the IAEA and then analyzed by a network of laboratories located in many Member States and the IAEA's own Safeguards Analytical Laboratory in Seibersdorf, Austria. Historically, the USSP was instrumental in introd… more
Date: July 13, 2008
Creator: Hoffheins,B.
Partner: UNT Libraries Government Documents Department
open access

Flavorful supersymmetry

Description: Weak scale supersymmetry provides elegant solutions to many of the problems of the standard model, but it also generically gives rise to excessive flavor and CP violation. We show that, if the mechanism that suppresses the Yukawa couplings also suppresses flavor changing interactions in the supersymmetry breaking parameters, essentially all the low energy flavor and CP constraints can be satisfied. The standard assumption of flavor universality in the supersymmetry breaking sector is not necess… more
Date: December 13, 2007
Creator: Nomura, Yasunori; Nomura, Yasunori; Papucci, Michele & Stolarski, Daniel
Partner: UNT Libraries Government Documents Department
open access

Language Classification using N-grams Accelerated by FPGA-based Bloom Filters

Description: N-Gram (n-character sequences in text documents) counting is a well-established technique used in classifying the language of text in a document. In this paper, n-gram processing is accelerated through the use of reconfigurable hardware on the XtremeData XD1000 system. Our design employs parallelism at multiple levels, with parallel Bloom Filters accessing on-chip RAM, parallel language classifiers, and parallel document processing. In contrast to another hardware implementation (HAIL algorithm… more
Date: September 13, 2007
Creator: Jacob, A. & Gokhale, M.
Partner: UNT Libraries Government Documents Department
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USSP-IAEA Workshop on Advanced Sensors for Safeguards

Description: The IAEA Medium Term Strategy (2006-2011) defines a number of specific goals in respect to the IAEA's ability to provide assurances to the international community regarding the peaceful use of nuclear energy through States adherences to their respective non-proliferation treaty commitments. The IAEA has long used and still needs the best possible sensors to detect and measure nuclear material. The Department of Safeguards, recognizing the importance of safeguards-oriented R&amp;D, especially ta… more
Date: November 13, 2007
Creator: Pepper,Susan; Queirolo, A.; Zendel, M.; Whichello, J.; Annese, C.; Griebe, J. et al.
Partner: UNT Libraries Government Documents Department
open access

A multi-model assessment of pollution transport to the Arctic

Description: We examine the response of Arctic gas and aerosol concentrations to perturbations in pollutant emissions from Europe, East and South Asia, and North America using results from a coordinated model intercomparison. These sensitivities to regional emissions (mixing ratio change per unit emission) vary widely across models and species. Intermodel differences are systematic, however, so that the relative importance of different regions is robust. North America contributes the most to Arctic ozone po… more
Date: March 13, 2008
Creator: Shindell, D T; Chin, M; Dentener, F; Doherty, R M; Faluvegi, G; Fiore, A M et al.
Partner: UNT Libraries Government Documents Department
open access

A Study of Detonation Propagation and Diffraction with Compliant Confinement

Description: A previous computational study of diffracting detonations with the ignition-and-growth model demonstrated that contrary to experimental observations, the computed solution did not exhibit dead zones. For a rigidly confined explosive it was found that while diffraction past a sharp corner did lead to a temporary separation of the lead shock from the reaction zone, the detonation re-established itself in due course and no pockets of unreacted material were left behind. The present investigation c… more
Date: August 13, 2007
Creator: Banks, J; Schwendeman, D; Kapila, A & Henshaw, W
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

Product Quality Assurance for Off-Grid Lighting in Africa

Description: Although the emergence of markets for high efficiency off-grid lighting technologies holds promise, realizing the potential of this opportunity on a long-term, sustainable basis requires careful attention to issues of product quality, consumer protection, and the potential for significant 'market spoiling', in anticipation of increases of sales of low cost, low performance off-grid lighting products. The goal of the Lighting Africa quality assurance workshop was to articulate strategies to miti… more
Date: July 13, 2008
Creator: Bank, World; Mills, Evan & Mills, Evan
Partner: UNT Libraries Government Documents Department
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