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Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus eXperiment divertor (open access)

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus eXperiment divertor

None
Date: May 7, 2012
Creator: Scotti, F; Roquemore, A L & Soukhanovskii, V A
System: The UNT Digital Library
The NIF 4.5-m nTOF Detectors (open access)

The NIF 4.5-m nTOF Detectors

The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator/photodetector neutron-time-of-flight (nTOF) detectors for measuring DD and DT neutron yields. The detectors provided consistent neutron yield benchmarks from below 1E9 (DD) to nearly 1E15 (DT). The detectors demonstrated DT yield measurement precisions better than 5%, but the absolute accuracy relies on cross calibration with independent measurements of absolute neutron yield. The 4.5-m nTOF data have provided a useful testbed for testing improvements in nTOF data processing, especially with respect to improving the accuracies of the detector impulse response functions. The resulting improvements in data analysis methods have produced more accurate results. In summary, results from the NIF 4.5-m nTOF detectors have provided consistent measurements of DD and DT neutron yields from laser-fusion implosions.
Date: May 7, 2012
Creator: Moran, M. J.; Bond, E. J.; Clancy, T. J.; Eckart, M. J.; Khater, H. Y. & Glebov, V. Y.
System: The UNT Digital Library
Predicting Image Blur in Proton Radiography: Comparisons Between Measurements and Monte Carlo Simulations (open access)

Predicting Image Blur in Proton Radiography: Comparisons Between Measurements and Monte Carlo Simulations

Given the cost and lead-times involved in high-energy proton radiography, it is prudent to model proposed radiographic experiments to see if the images predicted would return useful information. We recently modified our raytracing transmission radiography modeling code HADES to perform simplified Monte Carlo simulations of the transport of protons in a proton radiography beamline. Beamline objects include the initial diffuser, vacuum magnetic fields, windows, angle-selecting collimators, and objects described as distorted 2D (planar or cylindrical) meshes or as distorted 3D hexahedral meshes. We present an overview of the algorithms used for the modeling and code timings for simulations through typical 2D and 3D meshes. We next calculate expected changes in image blur as scattering materials are placed upstream and downstream of a resolution test object (a 3 mm thick sheet of tantalum, into which 0.4 mm wide slits have been cut), and as the current supplied to the focusing magnets is varied. We compare and contrast the resulting simulations with the results of measurements obtained at the 800 MeV Los Alamos LANSCE Line-C proton radiography facility.
Date: May 7, 2010
Creator: Schach von Wittenau, Alexis E.; Aufderheide, Maurice B., III & Henderson, Gary L.
System: The UNT Digital Library
Uncertainty Analysis Technique for OMEGA Dante Measurements (open access)

Uncertainty Analysis Technique for OMEGA Dante Measurements

The Dante is an 18 channel X-ray filtered diode array which records the spectrally and temporally resolved radiation flux from various targets (e.g. hohlraums, etc.) at X-ray energies between 50 eV to 10 keV. It is a main diagnostics installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The absolute flux is determined from the photometric calibration of the X-ray diodes, filters and mirrors and an unfold algorithm. Understanding the errors on this absolute measurement is critical for understanding hohlraum energetic physics. We present a new method for quantifying the uncertainties on the determined flux using a Monte-Carlo parameter variation technique. This technique combines the uncertainties in both the unfold algorithm and the error from the absolute calibration of each channel into a one sigma Gaussian error function. One thousand test voltage sets are created using these error functions and processed by the unfold algorithm to produce individual spectra and fluxes. Statistical methods are applied to the resultant set of fluxes to estimate error bars on the measurements.
Date: May 7, 2010
Creator: May, M J; Widmann, K; Sorce, C; Park, H & Schneider, M
System: The UNT Digital Library
LLNL X-band RF System (open access)

LLNL X-band RF System

None
Date: May 7, 2013
Creator: Marsh, R A; Anderson, G G; Anderson, S G; Fisher, S E; Gibson, D J; Hartemann, F V et al.
System: The UNT Digital Library
Gamma-Ray Band and Multi-Waveband Variability of Blazars with the Fermi Large Area Space Telescope (open access)

Gamma-Ray Band and Multi-Waveband Variability of Blazars with the Fermi Large Area Space Telescope

None
Date: May 7, 2013
Creator: Ciprini, Stefano
System: The UNT Digital Library
What Scientific Applications can Benefit from Hardware Transactional Memory? (open access)

What Scientific Applications can Benefit from Hardware Transactional Memory?

None
Date: May 7, 2012
Creator: Schindewolf, M; Bihari, B; Gyllenhaal, J; Schulz, M; Wang, A & Karl, W
System: The UNT Digital Library
Discovery of Very High Energy Gamma-Ray Emission from 1FGL J2001.1 4351 by MAGIC (open access)

Discovery of Very High Energy Gamma-Ray Emission from 1FGL J2001.1 4351 by MAGIC

We report the discovery of Very High Energy (VHE; >100 GeV) gamma-ray emission from the source 1FGL J2001.1+4351, (RA 20 01 13.5, dec 43 53 02.8, J2000), which is positionally consistent with the location of the flat spectrum radio source MG4 J200112+4352 (RA 20 01 12.9, dec 43 52 52.8, J2000). The VHE detection is based on a 1.5 hour-long observation performed on July 16th in stereoscopic mode with the two 17m diameter imaging Cherenkov telescopes on La Palma, Canary Islands, Spain. The preliminary analysis of the MAGIC data using the standard cuts optimized for soft energy spectra sources yields a detection of 125 gamma-rays above 90 GeV, corresponding to a pre-trail statistical significance of 7.6 standard deviations. The observed flux is estimated to be {approx}20% of the Crab nebula flux above 100 GeV. Earlier MAGIC observations indicated a substantially lower flux; hence indicating that the source is variable on a few days timescale.
Date: May 7, 2012
Creator: Berger, Karsten; Paneque, David & Giavitto, Gianluca
System: The UNT Digital Library
Enhanced NIF Neutron Activation Diagnostics (open access)

Enhanced NIF Neutron Activation Diagnostics

None
Date: May 7, 2012
Creator: Yeamans, C B; Bleuel, D L & Bernstein, L A
System: The UNT Digital Library
Intermolecular potential parameters and combining rules determined from viscosity data (open access)

Intermolecular potential parameters and combining rules determined from viscosity data

The Law of Corresponding States has been demonstrated for a number of pure substances and binary mixtures, and provides evidence that the transport properties viscosity and diffusion can be determined from a molecular shape function, often taken to be a Lennard-Jones 12-6 potential, that requires two scaling parameters: a well depth {var_epsilon}{sub ij} and a collision diameter {sigma}{sub ij}, both of which depend on the interacting species i and j. We obtain estimates for {var_epsilon}{sub ij} and {sigma}{sub ij} of interacting species by finding the values that provide the best fit to viscosity data for binary mixtures, and compare these to calculated parameters using several 'combining rules' that have been suggested for determining parameter values for binary collisions from parameter values that describe collisions of like molecules. Different combining rules give different values for {sigma}{sub ij} and {var_epsilon}{sub ij} and for some mixtures the differences between these values and the best-fit parameter values are rather large. There is a curve in ({var_epsilon}{sub ij}, {sigma}{sub ij}) space such that parameter values on the curve generate a calculated viscosity in good agreement with measurements for a pure gas or a binary mixture. The various combining rules produce couples of parameters {var_epsilon}{sub ij}, …
Date: May 7, 2010
Creator: Bastien, Lucas A.J.; Price, Phillip N. & Brown, Nancy J.
System: The UNT Digital Library
Diagnostic options for radiative divertor feedback control on NSTX-U (open access)

Diagnostic options for radiative divertor feedback control on NSTX-U

None
Date: May 7, 2012
Creator: Soukhanovskii, V A; Gerhardt, S P; Kaita, R; McLean, A G & Raman, R
System: The UNT Digital Library
Search for Extra Dimensions Using Diphoton Events in 7 TeV Proton-Proton Collisions with the ATLAS Detector (open access)

Search for Extra Dimensions Using Diphoton Events in 7 TeV Proton-Proton Collisions with the ATLAS Detector

None
Date: May 7, 2013
Creator: Aad, Georges
System: The UNT Digital Library
Infinite Dilution Activity Coefficients of Solutes Dissolved in Two Trihexyl(tetradecyl)phosphonium ionic liquids (open access)

Infinite Dilution Activity Coefficients of Solutes Dissolved in Two Trihexyl(tetradecyl)phosphonium ionic liquids

Article discussing infinite dilution activity coefficients of solutes dissolved in two trihexyl(tetradecyl)phosphonium ionic liquids.
Date: May 7, 2014
Creator: Mutelet, Fabrice; Alonso, Dominique; Stephens, Timothy W.; Acree, William E. (William Eugene) & Baker, Gary A.
System: The UNT Digital Library
An Efficient Synthesis of Deoxyrhapontigenin-3-O-β-d-glucuronide, a Brain-Targeted Derivative of Dietary Resveratrol, and Its Precursor 4′-O-Me-Resveratrol (open access)

An Efficient Synthesis of Deoxyrhapontigenin-3-O-β-d-glucuronide, a Brain-Targeted Derivative of Dietary Resveratrol, and Its Precursor 4′-O-Me-Resveratrol

Article discusses the identification of the brain-available phenol glucuronide metabolite deoxyrhapontigenin-3-O-β-d-glucuronide (5) in perfused rat brains following subacute treatment with the stilbene resveratrol.
Date: May 7, 2019
Creator: de Fátima, Ângelo; Docampo-Palacios, Maite; Alvarez-Hernandez, Anislay; Pasinetti, Giulio M. & Dixon, R. A.
System: The UNT Digital Library
Enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production (open access)

Enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production

Article on the enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production.
Date: May 7, 2013
Creator: Shen, Hui; Poovaiah, Charleson R.; Ziebell, Angela; Tschaplinski, Timothy J.; Pattathil, Sivakumar; Gjersing, Erica et al.
System: The UNT Digital Library
Enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production (open access)

Enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production

Article on enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production.
Date: May 7, 2013
Creator: Shen, Hui; Poovaiah, Charleson R.; Ziebell, Angela; Tschaplinski, Timothy J.; Pattathil, Sivakumar; Gjersing, Erica et al.
System: The UNT Digital Library
Photon Enhanced Thermionic Emission for Solar Energy Harvesting Final Report to the Global Climate and Energy Project (open access)

Photon Enhanced Thermionic Emission for Solar Energy Harvesting Final Report to the Global Climate and Energy Project

None
Date: May 7, 2013
Creator: Melosh, Nicholas; Shen, Zhi-Xun; Schwede, Jared; Riley, Dan; Rosenthal, Samuel; Narasimhan, Vijay et al.
System: The UNT Digital Library