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Corrosion-resistant multilayer coatings for the 28-75 nm wavelength region

Description: Corrosion has prevented use of SiC/Mg multilayers in applications requiring good lifetime stability. We have developed Al-based barrier layers that dramatically reduce corrosion, while preserving high reflectance and low stress. The aforementioned advances may enable the implementation of corrosion-resistant, high-performance SiC/Mg coatings in the 28-75 nm region in applications such as tabletop EUV/soft x-ray laser sources and solar physics telescopes. Further study and optimization of corros… more
Date: November 8, 2011
Creator: Soufli, R.; Fernandez-Perea, Monica & Al, E. T.
Partner: UNT Libraries Government Documents Department
open access

Bioinspired Molecular Co-Catalysts Bonded to a Silicon Photocathode for Solar Hydrogen Evolution

Description: The production of fuels from sunlight represents one of the main challenges in the development of a sustainable energy system. Hydrogen is the simplest fuel to produce and although platinum and other noble metals are efficient catalysts for photoelectrochemical hydrogen evolution earth-abundant alternatives are needed for large-scale use. We show that bioinspired molecular clusters based on molybdenum and sulphur evolve hydrogen at rates comparable to that of platinum. The incomplete cubane-lik… more
Date: November 8, 2011
Creator: Hou, Yidong
Partner: UNT Libraries Government Documents Department
open access

DEVELOPMENT AND DEPLOYMENT OF THE MOBILE ARM RETRIEVAL SYSTEM (MARS) - 12187

Description: Washington River Protection Solutions (WRPS) is developing and deploying Mobile Arm Retrieval System (MARS) technologies solutions to support retrieval of radioactive and chemical waste from underground single shell storage tanks (SST) located at the Hanford Site, which is near Richland, Washington. WRPS has developed the MARS using a standardized platform that is capable of deploying multiple retrieval technologies. To date, WRPS, working with their mentor-protege company, Columbia Energy and … more
Date: November 8, 2011
Creator: CA, BURKE; MR, LANDON & CE, HANSON
Partner: UNT Libraries Government Documents Department
open access

Crab Cavities for Linear Colliders

Description: Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band co… more
Date: November 8, 2011
Creator: Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; U., /Cockcroft Inst. Accel. Sci. Tech. /Lancaster et al.
Partner: UNT Libraries Government Documents Department
open access

Fast Shower Simulation in the ATLAS Calorimeter

Description: The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Gean… more
Date: November 8, 2011
Creator: Barberio, E.; Boudreau, J.; Butler, B.; Cheung, S. L.; Dell'Acqua, A.; Di Simone, A. et al.
Partner: UNT Libraries Government Documents Department
open access

Excited Baryons in Holographic QCD

Description: The light-front holographic QCD approach is used to describe baryon spectroscopy and the systematics of nucleon transition form factors. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. The transition from the hard-scattering perturbative domain to the non-perturbative region is sensitive to the detailed dynamics of confined quarks and gluons. Computation… more
Date: November 8, 2011
Creator: de Teramond, Guy F.; U., /Costa Rica; Brodsky, Stanley J. & /SLAC /Southern Denmark U., CP3-Origins
Partner: UNT Libraries Government Documents Department
open access

The Physics of Ion Decoupling in Magnetized Plasma Explosions

Description: When a finite pulse of plasma expands into a magnetized background plasma, MHD predicts the pulse expel background plasma and its B-field - i.e. cause a magnetic 'bubble'. The expanding plasma is confined within the bubble, later to escape down the B-field lines. MHD suggests that the debris energy goes to expelling the B-field from the bubble volume and kinetic energy of the displaced background. For HANEs, this is far from the complete story. For many realistic HANE regimes, the long mean-fre… more
Date: February 8, 2011
Creator: Hewett, D; Larson, D & Brecht, S
Partner: UNT Libraries Government Documents Department
open access

ELECTRONICS UPGRADE TO THE SAVANNAH RIVER NATIONAL LABORATORY COULOMETER FOR PLUTONIUM AND NEPTUNIUM ASSAY

Description: The Savannah River Site (SRS) has the analytical measurement capability to perform high-precision plutonium concentration measurements by controlled-potential coulometry. State-of-the-art controlled-potential coulometers were designed and fabricated by the Savannah River National Laboratory and installed in the Analytical Laboratories process control laboratory. The Analytical Laboratories uses coulometry for routine accountability measurements of and for verification of standard preparations u… more
Date: July 8, 2011
Creator: Cordaro, J.; Holland, M.; Reeves, G.; Nichols, S. & Kruzner, A.
Partner: UNT Libraries Government Documents Department
open access

Itinerant and localized magnetic moments in ferrimagnetic Mn{sub 2}CoGa thin films identified with x-ray magnetic linear dichroism: experiment and ab initio theory

Description: Epitaxial thin films of the half-metallic X{sub a}-compound Mn{sub 2}CoGa (Hg{sub 2}CuTi prototype) were prepared by dc magnetron co-sputtering with different heat treatments on MgO (001) substrates. High-quality #12;lms with a bulk magnetization of 1.95(5) {mu}{sub #22;}B per unit cell were obtained. The average Mn magnetic moment and the Co moment are parallel, in agreement with theory. The x-ray magnetic circular dichroism spectra agree with calculations based on density functional theory an… more
Date: August 8, 2011
Creator: Meinert, Markus; Schmalhorst, Jan-Michael; Klewe, Cristoph; Reiss, Gunter; Arenholz, Elke; Bohnert, Tim et al.
Partner: UNT Libraries Government Documents Department
open access

Fermi Large Area Telescope Observations of the Cygnus Loop Supernova Remnant

Description: We present an analysis of the gamma-ray measurements by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) Cygnus Loop (G74.0-8.5). We detect significant gamma-ray emission associated with the SNR in the energy band 0.2-100 GeV. The gamma-ray spectrum shows a break in the range 2-3 GeV. The gamma-ray luminosity is {approx} 1 x 10{sup 33} erg s{sup -1} between 1-100 GeV, much lower than those of other GeV-emitting SNRs. The mor… more
Date: November 8, 2011
Creator: Katagiri, H.; Tibaldo, L.; Ballet, J.; Giordano, F.; Grenier, I. A.; Porter, T. A. et al.
Partner: UNT Libraries Government Documents Department
open access

Study of Lower Emittance Lattices for SPEAR3

Description: We study paths to significantly reduce the emittance of the SPEAR3 storage ring. Lattice possibilities are explored with the GLASS technique. New lattices are designed and optimized for practical dynamic aperture and beam lifetime. Various techniques are employed to optimize the nonlinear dynamics, including the Elegant-based genetic algorithm. Experimental studies are also carried out on the ring to validate the lattice design. The SPEAR3 storage ring is a third generation light source which h… more
Date: November 8, 2011
Creator: Huang, Xiaobiao; Nosochkov, Yuri; Safranek, James A. & Wang, Lanfa
Partner: UNT Libraries Government Documents Department
open access

Radiation-Hardened Gallium Nitride Detector and Arrays for Fusion Diagnostics

Description: This poster reports testing to confirm that GaN devices exhibit the extreme radiation hardness needed for use at the NIF, functioning properly after 1x10{sup 12} protons/cm{sup 2} proton irradiation in one year.
Date: September 8, 2011
Creator: Sun, K. X., and MacNeil, L.
Partner: UNT Libraries Government Documents Department
open access

The influence of working gas pressure on interlayer mixing in magnetron-deposited Mo/Si multilayers

Description: Impact of Ar gas pressure (1-4 mTorr) on the growth of amorphous interlayers in Mo/Si multilayers deposited by magnetron sputtering was investigated by small-angle x-ray scattering ({lambda} = 0.154 nm) and methods of cross-sectional transmission electron microscopy. Some reduction of thickness of the amorphous inter-layers with Ar pressure increase was found, while composition of the layers was enriched with molybdenum. The interface modification resulted in raise of EUV reflectance of the Mo/… more
Date: August 8, 2011
Creator: Pershyn, Yuriy; Gullikson, Erik; Artyukov, Igor; Kondratenko, Valeriy; Sevryukova, Victoriya; Voronov, Dmitriy et al.
Partner: UNT Libraries Government Documents Department
open access

THz Pump and X-Ray Probe Development at LCLS

Description: We report on measurements of broadband, intense, coherent transition radiation at terahertz frequencies, generated as the highly compressed electron bunches in Linear Coherent Light Source (LCLS) pass through a thin metal foil. The foil is inserted at 45{sup o} to the electron beam, 31 m downstream of the undulator. The THz emission passes downward through a diamond window to an optical table below the beamline. A fully compressed 350-pC bunch produces up to 0.5 mJ in a nearly half-cycle pulse … more
Date: November 8, 2011
Creator: Fisher, Alan S; /SLAC, LCLS; Durr, Hermann; /SIMES, Stanford /SLAC, PULSE; Lindenberg, Aaron; Stanford U., Materials Sci.Dept. et al.
Partner: UNT Libraries Government Documents Department
open access

THERMAL MODELING ANALYSIS OF SRS 70 TON CASK

Description: The primary objective of this work was to perform the thermal calculations to evaluate the Material Test Reactor (MTR) fuel assembly temperatures inside the SRS 70-Ton Cask loaded with various bundle powers. MTR fuel consists of HFBR, MURR, MIT, and NIST. The MURR fuel was used to develop a bounding case since it is the fuel with the highest heat load. The results will be provided for technical input for the SRS 70 Ton Cask Onsite Safety Assessment. The calculation results show that for the SRS… more
Date: March 8, 2011
Creator: Lee, S.; Jordan, J. & Hensel, S.
Partner: UNT Libraries Government Documents Department
open access

Bootstrapping the Three-Loop Hexagon

Description: We consider the hexagonal Wilson loop dual to the six-point MHV amplitude in planar N = 4 super Yang-Mills theory. We apply constraints from the operator product expansion in the near-collinear limit to the symbol of the remainder function at three loops. Using these constraints, and assuming a natural ansatz for the symbol's entries, we determine the symbol up to just two undetermined constants. In the multi-Regge limit, both constants drop out from the symbol, enabling us to make a non-trivia… more
Date: November 8, 2011
Creator: Dixon, Lance J.; Drummond, James M. & Henn, Johannes M.
Partner: UNT Libraries Government Documents Department
open access

Application of an EMCCD Camera for Calibration of Hard X-Ray Telescopes

Description: Recent technological innovations now make it feasible to construct hard x-ray telescopes for space-based astronomical missions. Focusing optics are capable of improving the sensitivity in the energy range above 10 keV by orders of magnitude compared to previously used instruments. The last decade has seen focusing optics developed for balloon experiments and they will soon be implemented in approved space missions such as the Nuclear Spectroscopic Telescope Array (NuSTAR) and ASTRO-H. The full … more
Date: November 8, 2011
Creator: Vogel, J K; Pivovaroff, M J; Nagarkar, V V; Kudrolli, H; Madsen, K K; Koglin, J E et al.
Partner: UNT Libraries Government Documents Department
open access

Observation of the dynamics leading to a conical intersection in dissociative electron attachment to water

Description: Following prior work on the lower-energy resonances, we apply techniques of momentum imaging and ab initio scattering calculations to the process of dissociative electron attachment to water via the highest-energy {sup 2}B{sub 2} resonance. We focus on the H{sup -} anion fragment, which is produced via dynamics passing through and avoiding the conical intersection with the lower A{sub 1} state, leading to OH ((sup 2}{Pi}#5;) and OH ({sup 2}{Sigma}#6;), respectively. The momentum imaging techniq… more
Date: June 8, 2011
Creator: Haxton, Dan; Adaniya, Hidihito; Slaughter, Dan; Rudek, B.; Osipov, Timur; Weber, Thorsten et al.
Partner: UNT Libraries Government Documents Department
open access

Data Mining Empowers the Generation of a Novel Class of Chromosome-specific DNA Probes

Description: Probes that allow accurate delineation of chromosome-specific DNA sequences in interphase or metaphase cell nuclei have become important clinical tools that deliver life-saving information about the gender or chromosomal make-up of a product of conception or the probability of an embryo to implant, as well as the definition of tumor-specific genetic signatures. Often such highly specific DNA probes are proprietary in nature and have been the result of extensive probe selection and optimization … more
Date: March 8, 2011
Creator: Zeng, Hui; Weier, Heinz-Ulrich G.; Kwan, Johnson; Wang, Mei & O'Brien, Benjamin
Partner: UNT Libraries Government Documents Department
open access

Terahertz Light Source and User Area at FACET

Description: FACET at SLAC provides high charge, high peak current, low emittance electron beam that is bunched at THz wavelength scale during its normal operation. A THz light source based coherent transition radiation (CTR) from this beam would potentially be the brightest short-pulse THz source ever constructed. Efforts have been put into building this photon source together with a user area, to provide a platform to utilize this unique THz radiation for novel nonlinear and ultrafast phenomena researches… more
Date: November 8, 2011
Creator: Wu, Z.; Li, S. Z.; Litos, M.; Fisher, A. D. & Hogan, M. J.
Partner: UNT Libraries Government Documents Department
open access

Summary for Policy Makers: Intergovernmental Panel on Climate Change Special Report Renewable Energy Sources (SRREN)

Description: The Working Group III Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) presents an assessment of the literature on the scientific, technological, environmental, economic and social aspects of the contribution of six renewable energy (RE) sources to the mitigation of climate change. It is intended to provide policy relevant information to governments, intergovernmental processes and other interested parties. This Summary for Policymakers provides an overview of th… more
Date: May 8, 2011
Creator: Arvizu, Dan; Bruckner, Thomas; Christensen, John; Devernay, Jean-Michel; Faaij , Andre; Fischedick, Manfred et al.
Partner: UNT Libraries Government Documents Department
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