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Gas-Phase Molecular Dynamics: Theoretical Studies In Spectroscopy and Chemical Dynamics

Description: The main goal of this program is the development and application of computational methods for studying chemical reaction dynamics and molecular spectroscopy in the gas phase. We are interested in developing rigorous quantum dynamics algorithms for small polyatomic systems and in implementing approximate approaches for complex ones. Particular focus is on the dynamics and kinetics of chemical reactions and on the rovibrational spectra of species involved in combustion processes. This research al… more
Date: May 29, 2012
Creator: Yu, H. G. & Muckerman, J. T.
Partner: UNT Libraries Government Documents Department
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Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species

Description: This research is carried out as part of the Gas-Phase Molecular Dynamics program in the Chemistry Department at Brookhaven National Laboratory. Chemical intermediates in the elementary gas-phase reactions involved in combustion chemistry are investigated by high resolution spectroscopic tools. Production, reaction, and energy transfer processes are investigated by transient, double resonance, polarization and saturation spectroscopies, with an emphasis on technique development and connection wi… more
Date: May 29, 2012
Creator: Hall, G. E. & Goncharov, V.
Partner: UNT Libraries Government Documents Department
open access

Agreement Between Local and Global Measurements of the London Penetration Depth

Description: Recent measurements of the superconducting penetration depth in Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} appeared to disagree on the magnitude and curvature of {delta}{lambda}{sub ab}(T), even near optimal doping. These measurements were carried out on different samples grown by different groups. To understand the discrepancy, we use scanning SQUID susceptometry and a tunnel diode resonator to measure the penetration depth in a single sample. The penetration depth observed by the two techniques… more
Date: August 29, 2012
Creator: Lippman, Thomas M.; Kalisky, Beena; Kim, Hyunsoo; Tanatar, Makariy; Budko, Sergey L.; Canfield, Paul C. et al.
Partner: UNT Libraries Government Documents Department
open access

Prototyping of the ILC Baseline Positron Target

Description: The ILC positron system uses novel helical undulators to create a powerful photon beam from the main electron beam. This beam is passed through a titanium target to convert it into electron-positron pairs. The target is constructed as a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train over 10 cm. A pulsed flux concentrating magnet is used to increase the positron capture efficiency. It is cooled to liquid nitrogen temperatures to maximize the flatness of the magnetic fi… more
Date: February 29, 2012
Creator: Gronberg, J.; Brooksby, C.; Piggott, T.; Abbott, R.; Javedani, J. & Cook, E.
Partner: UNT Libraries Government Documents Department
open access

Fermi Large Area Telescope Gamma-Ray Detection of the Radio Galaxy M87

Description: No Description Available.
Date: March 29, 2012
Creator: Abdo, A. A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. et al.
Partner: UNT Libraries Government Documents Department
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CONTAINMENT OF LOW-LEVEL RADIOACTIVE WASTE AT THE DOE SALTSTONE DISPOSAL FACILITY

Description: As facilities look for permanent storage of toxic materials, they are forced to address the long-term impacts to the environment as well as any individuals living in affected area. As these materials are stored underground, modeling of the contaminant transport through the ground is an essential part of the evaluation. The contaminant transport model must address the long-term degradation of the containment system as well as any movement of the contaminant through the soil and into the groundwa… more
Date: March 29, 2012
Creator: Jordan, J. & Flach, G.
Partner: UNT Libraries Government Documents Department
open access

Considerations For Contractile Electroactive Materials and Actuators

Description: Electroactive polymers (EAPs) that bend, swell, ripple (first generation materials), and now contract with low electric input (new development) have been produced. The mechanism of contraction is not well understood. Radionuclide-labeled experiments, molecular modeling, electrolyte experiments, pH experiments, and an ionic concentration experiment were used to determine the chain of events that occur during contraction and, reciprocally, expansion when the polarity is reversed, in these ionic E… more
Date: February 29, 2012
Creator: Lenore Rasmussen, Lewis D. Meixler and Charles A. Gentile
Partner: UNT Libraries Government Documents Department
open access

Coherent Synchrotron Radiation: Theory and Simulations.

Description: The physics of coherent synchrotron radiation (CSR) emitted by ultra-relativistic electron bunches, known since the last century, has become increasingly important with the development of high peak current free electron lasers and shorter bunch lengths in storage rings. Coherent radiation can be described as a low frequency part of the familiar synchrotron radiation in bending magnets. As this part is independent of the electron energy, the fields of different electrons of a short bunch can be … more
Date: March 29, 2012
Creator: Novokhatski, Alexander
Partner: UNT Libraries Government Documents Department
open access

Fermi LAT Detection of Pulsed Gamma-Rays From the Vela-Like Pulsars PSR J1048-5832 and PSR J2229+6114

Description: We report the detection of {gamma}-ray pulsations ({ge}0.1 GeV) from PSR J2229+6114 and PSR J1048-5832, the latter having been detected as a low-significance pulsar by EGRET. Data in the {gamma}-ray band were acquired by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, while the radio rotational ephemerides used to fold the {gamma}-ray light curves were obtained using the Green Bank Telescope, the Lovell telescope at Jodrell Bank, and the Parkes Telescope. The two youn… more
Date: March 29, 2012
Creator: Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Axelsson, M.; Baldini, L. et al.
Partner: UNT Libraries Government Documents Department
open access

HIGH-DENSITY, BIO-COMPATIBLE, AND HERMETIC ELECTRICAL FEEDTHROUGHS USING EXTRUDED METAL VIAS

Description: Implanted medical devices such as pacemakers and neural prosthetics require that the electronic components that power these devices are protected from the harsh chemical and biological environment of the body. Typically, the electronics are hermetically sealed inside a bio-compatible package containing feedthroughs that transmit electrical signals, while being impermeable to particles or moisture. We present a novel approach for fabricating one of the highest densities of biocompatible hermetic… more
Date: March 29, 2012
Creator: Tooker, A; Shah, K; Tolosa, V; Sheth, H; Felix, S; Delima, T et al.
Partner: UNT Libraries Government Documents Department
open access

Pedestal Fueling Simulations with a Coupled Kinetic-kinetic Plasma-neutral Transport Code

Description: A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the ma… more
Date: August 29, 2012
Creator: D.P. Stotler, C.S. Chang, S.H. Ku, J. Lang and G.Y. Park
Partner: UNT Libraries Government Documents Department
open access

Determination of the S-Wave Pi Pi Scattering Lengths From a Study of K - to Pi - Pi0 Pi0 Decays

Description: We report the results from a study of the full sample of {approx}6.031 x 10{sup 7} K{sup {+-}} {yields} {pi}{sup {+-}}{pi}{sup 0}{pi}{sup 0} decays recorded by the NA48/2 experiment at the CERN SPS. As first observed in this experiment, the {pi}{sup 0}{pi}{sup 0} invariant mass (M{sub 00}) distribution shows a cusp-like anomaly in the region around M{sub 00} = 2m{sub +}, where m{sub +} is the charged pion mass. This anomaly has been interpreted as an effect due mainly to the final state charge … more
Date: March 29, 2012
Creator: Batley, J. R.; Culling, A. J.; Kalmus, G.; Lazzeroni, C.; Munday, D. J.; Slater, M. W. et al.
Partner: UNT Libraries Government Documents Department
open access

Scenarios for the ATF2 Ultra-Low Betas Proposal

Description: The current ATF2 Ultra-Low beta proposal was designed to achieve 20nm vertical IP beam size without considering the multipolar components of the FD magnets. In this paper we describe different scenarios that avoid the detrimental effect of these multipolar errors to the beam size at the interaction point (IP). The simplest approach consists in modifying the optics, but other solutions are studied as the introduction of super-conducting wigglers to reduce the emittance or the replacement of the … more
Date: June 29, 2012
Creator: Marin, Eduardo; Tomas, Rogelio; Bambade, Philip; Kuroda, Shigeru; Okugi, Toshiyuki; Tauchi, Toshiaki et al.
Partner: UNT Libraries Government Documents Department
open access

Fermi LAT Observations of LS 5039

Description: The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variability that is consistent with the binary period, with the emission being modulated with a period of 3.903 {+-} 0.005 days; the first detection of this modulation at GeV energies. The light curve is characterized by a broad peak around superior conjunction in agreement with inverse Compton scattering m… more
Date: March 29, 2012
Creator: Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwood, W. B.; Axelsson, M.; Baldini, L. et al.
Partner: UNT Libraries Government Documents Department
open access

Sloan Digital Sky Survey Photometric Calibration Revisited

Description: The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recom… more
Date: June 29, 2012
Creator: Marriner, John
Partner: UNT Libraries Government Documents Department
open access

The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds

Description: We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance … more
Date: February 29, 2012
Creator: Busha, Michael T.; Marshall, Philip J.; Wechsler, Risa H.; Klypin, Anatoly & Primack, Joel
Partner: UNT Libraries Government Documents Department
open access

Distinguishing Pu Metal From Pu Oxide Using Fast Neutron Counting

Description: We describe a method for simultaneously determining the {alpha}-ratio and k{sub eff} for fissile materials using fast neutrons. Our method is a generalization of the Hage-Cifarrelli method for determining k{sub eff} for fissile assemblies which utilizes the shape of the fast neutron spectrum. In this talk we illustrate the method using Monte Carlo simulations of the fast neutrons generated in PuO{sub 2} to calculate the fast neutron spectrum and Feynman correlations.
Date: May 29, 2012
Creator: Verbeke, J M; Chapline, G F; Nakae, L; Wurtz, R & Sheets, S
Partner: UNT Libraries Government Documents Department
open access

ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

Description: At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel t… more
Date: February 29, 2012
Creator: Ketusky, E. & Subramanian, K.
Partner: UNT Libraries Government Documents Department
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