85-GAL DRUM AND NUCFIL-007LS FILTERS (open access)

85-GAL DRUM AND NUCFIL-007LS FILTERS

{sm_bullet} 55-gallon drums were overpacked into 85-gallon drums {sm_bullet} ANucFiI-007LS long-stem filter was installed- NucFiI certified the use of NucFiI-007LS filters in 8S-gallon drums as DOT 7AType A - Wood wedges were used during the tests to center and . stabilize the inner 55-gallon drums {sm_bullet} During inspection, afew filters were found to be loose, canted, and/or with RTV seals broken - No contamination or loss of container integrity {sm_bullet} Discovered in November 2008 U.
Date: June 30, 2009
Creator: Woodbury, J. B.
System: The UNT Digital Library
COMPLIANCE FOR HANFORD WASTE RETRIEVAL RADIOACTIVE AIR EMISSIONS (open access)

COMPLIANCE FOR HANFORD WASTE RETRIEVAL RADIOACTIVE AIR EMISSIONS

{sm_bullet} Since 1970, approximately 38,000 suspect transuranic (TRU) and TRU waste cont{approx}iners have been placed in retrievable storage on the Hanford Site in the 200Area's burial grounds. {sm_bullet} TRU waste is defined as waste containing greater than 100 nanocuries/gram of alpha emitting transuranic isotopes with half lives greater than 20 years. {sm_bullet} The United States currentl{approx}permanently disposes of TRU waste at the Waste Isolation Pilot Plant (WIPP).
Date: June 30, 2009
Creator: SIMMONS, FM
System: The UNT Digital Library
Identification of Fissionable Materials Using the Tagged Neutron Technique (open access)

Identification of Fissionable Materials Using the Tagged Neutron Technique

This summary describes experiments to detect and identify fissionable materials using the tagged neutron technique. The objective of this work is to enhance homeland security capability to find fissionable material that may be smuggled inside shipping boxes, containers, or vehicles. The technique distinguishes depleted uranium from lead, steel, and tungsten. Future work involves optimizing the technique to increase the count rate by many orders of magnitude and to build in the additional capability to image hidden fissionable materials. The tagged neutron approach is very different to other techniques based on neutron die-away or photo-fission. This work builds on the development of the Associated Particle Imaging (API) technique at the Special Technologies Laboratory (STL) [1]. Similar investigations have been performed by teams at the Oak Ridge National Laboratory (ORNL), the Khlopin Radium Institute in Russia, and by the EURITRACK collaboration in the European Union [2,3,4].
Date: June 30, 2009
Creator: Keegan, R. P.; Hurley, J. P.; Tinsley, J. R. & Trainham, R.
System: The UNT Digital Library
IMPACT OF TARGET MATERIAL ACTIVATION ON PERSONNEL EXPOSURE AND RADIOACTIVE CONTAMINATION IN THE NATIONAL IGNITION FACILITY (open access)

IMPACT OF TARGET MATERIAL ACTIVATION ON PERSONNEL EXPOSURE AND RADIOACTIVE CONTAMINATION IN THE NATIONAL IGNITION FACILITY

Detailed activation analyses are performed for the different materials under consideration for use in the target capsules and hohlraums used during the ignition campaign on the National Ignition Facility. Results of the target material activation were additionally used to estimate the levels of contamination within the NIF target chamber and the workplace controls necessary for safe operation. The analysis examined the impact of using Be-Cu and Ge-doped CH capsules on the external dose received by workers during maintenance activities. Five days following a 20 MJ shot, dose rates inside the Target Chamber (TC) due to the two proposed capsule materials are small ({approx} 1 {micro}rem/h). Gold and depleted-uranium (DU) are considered as potential hohlraum materials. Following a shot, gold will most probably get deposited on the TC first wall. On the other hand, while noble-gas precursors from the DU are expected to stay in the TC, most of the noble gases are pumped out of the chamber and end up on the cryopumps. The dose rates inside the TC due to activated gold or DU, at 5 days following a 20 MJ shot, are about 1 mrem/h. Dose rates in the vicinity of the cryo-pumps (containing noble 'fission' gases) drop-off …
Date: June 30, 2009
Creator: Khater, H; Epperson, P; Thacker, R; Beale, R; Kohut, T & Brereton, S
System: The UNT Digital Library
Localized Plasticity in the Streamlined Genomes of Vinyl Chloride Respiring Dehalococcoides (open access)

Localized Plasticity in the Streamlined Genomes of Vinyl Chloride Respiring Dehalococcoides

Vinyl chloride (VC) is a human carcinogen and widespread priority pollutant. Here we report the first, to our knowledge, complete genome sequences of microorganisms able to respire VC, Dehalococcoides sp. strains VS and BAV1. Notably, the respective VC reductase encoding genes, vcrAB and bvcAB, were found embedded in distinct genomic islands (GEIs) with different predicted integration sites, suggesting that these genes were acquired horizontally and independently by distinct mechanisms. A comparative analysis that included two previously sequenced Dehalococcoides genomes revealed a contextually conserved core that is interrupted by two high plasticity regions (HPRs) near the Ori. These HPRs contain the majority of GEIs and strain-specific genes identified in the four Dehalococcoides genomes, an elevated number of repeated elements including insertion sequences (IS), as well as 91 of 96 rdhAB, genes that putatively encode terminal reductases in organohalide respiration. Only three core rdhA orthologous groups were identified, and only one of these groups is supported by synteny. The low number of core rdhAB, contrasted with the high rdhAB numbers per genome (up to 36 in strain VS), as well as their colocalization with GEIs and other signatures for horizontal transfer, suggests that niche adaptation via organohalide respiration is a fundamental ecological …
Date: June 30, 2009
Creator: McMurdie, Paul J.; Behrens, Sebastien F.; Muller, Jochen A.; Goke, Jonathan; Ritalahti, Kirsti M.; Wagner, Ryan et al.
System: The UNT Digital Library
Meson-Baryon Scattering Lengths from Mixed-Action Lattice QCD (open access)

Meson-Baryon Scattering Lengths from Mixed-Action Lattice QCD

The {pi}{sup +}{Sigma}{sup +}, {pi}{sup +}{Xi}{sup 0}, K{sup +}p, K{sup +}n, {bar K}{sup 0}{Sigma}{sup +}, and {bar K}{sup 0}{Xi}{sup 0} scattering lengths are calculated in mixed-action Lattice QCD with domain-wall valence quarks on the asqtad-improved coarse MILC configurations at four light-quark masses, and at two light-quark masses on the fine MILC configurations. Heavy Baryon Chiral Perturbation Theory with two and three flavors of light quarks is used to perform the chiral extrapolations. We find no convergence for the kaon-baryon processes in the three-flavor chiral expansion. Using the two-flavor chiral expansion, we find a{sub {pi}{sup +}{Sigma}{sup +}} = -0.197 {+-} 0.017 fm, and a{sub {pi}{sup +}{Xi}{sup 0}} = -0.098 {+-} 0.017 fm, where the comprehensive error includes statistical and systematic uncertainties.
Date: June 30, 2009
Creator: Beane, S; Detmold, W; Luu, T; Orginos, K; Parreno, A; Torok, A et al.
System: The UNT Digital Library
Pushing EUV lithography development beyond 22-nm half pitch (open access)

Pushing EUV lithography development beyond 22-nm half pitch

Microfield exposure tools (METs) have and continue to play a dominant role in the development of extreme ultraviolet (EUV) resists and masks. One of these tools is the SEMATECH Berkeley 0.3 numerical aperture (NA) MET. Here we investigate the possibilities and limitations of using the 0.3-NA MET for sub-22-nm half-pitch development. We consider mask resolution limitations and present a method unique to the centrally obscured MET allowing these mask limitations to be overcome. We also explore projection optics resolution limits and describe various illumination schemes allowing resolution enhancement. At 0.3-NA, the 0.5 k1 factor resolution limit is 22.5 nm meaning that conventional illumination is of limited utility for sub-22-nm development. In general resolution enhancing illumination encompasses increased coherence. We study the effect of this increased coherence on line-edge roughness, which along with resolution is another crucial factor in sub-22-nm resist development.
Date: June 30, 2009
Creator: Naulleau, Patrick; Anderson, Christopher N.; Baclea-an, Lorie-Mae; Denham, Paul; George, Simi; Goldberg, Kenneth A. et al.
System: The UNT Digital Library
THE RESULTS OF TESTING TO EVALUATE CRYSTAL FORMATION AND SETTLING IN THE COLD CRUCIBLE INDUCTION MELTER (open access)

THE RESULTS OF TESTING TO EVALUATE CRYSTAL FORMATION AND SETTLING IN THE COLD CRUCIBLE INDUCTION MELTER

The Cold Crucible Induction Melter (CCIM) technology offers the potential to increase waste loading for High Level Waste (HLW) glasses leading to significant improvements in waste throughput rates compared to the reference Joule Heated Melter (JHM). Prior to implementation of a CCIM in a production facility it is necessary to better understand processing constraints associated with the CCIM. The glass liquidus temperature requirement for processing in the CCIM is an open issue. Testing was conducted to evaluate crystal formation and crystal settling during processing in the CCIM to gain insight into the effects on processing. A high aluminum/high iron content glass composition with known crystal formation tendencies was selected for testing. A continuous melter test was conducted for approximately 51 hours. To evaluate crystal formation, glass samples were obtained from pours and from glass receipt canisters where the glass melt had varying residence time in the melter. Additionally, upon conclusion of the testing, glass samples from the bottom of the melter were obtained to assess the degree of crystal settling. Glass samples were characterized in an attempt to determine quantitative fractions of crystals in the glass matrix. Crystal identity and relative composition were determined using a combination of x-ray diffraction …
Date: June 30, 2009
Creator: Marra, J.
System: The UNT Digital Library
Study of the Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND (open access)

Study of the Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND

Radioactive isotopes produced through cosmic muon spallation are a background for rare event detection in {nu} detectors, double-beta-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of {sup 11}C. Data from the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillator, and for checking estimates from current simulations based upon MUSIC, FLUKA, and Geant4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be (2.8 {+-} 0.3) x 10{sup -4} n/({mu} {center_dot} (g/cm{sup 2})). For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.
Date: June 30, 2009
Creator: Collaboration, KamLAND; Abe, S.; Enomoto, S.; Furuno, K.; Gando, Y.; Ikeda, H. et al.
System: The UNT Digital Library
Techniques and use of a tunable, laser-based, MeV-Class Compton scattering light source (open access)

Techniques and use of a tunable, laser-based, MeV-Class Compton scattering light source

A Compton scattering {gamma}-ray source, capable of producing photons with energies ranging from 0.1 MeV to 0.9 MeV has been commissioned and characterized, and then used to perform nuclear resonance fluorescence (NRF) experiments. The key source parameters are the size (0.01 mm{sup 2}), horizontal and vertical divergence (6 x 10 mrad{sup 2}), duration (10 ps), spectrum and intensity (10{sup 5} photons/shot). These parameters are summarized by the peak brightness, 1.5 x 10{sup 15} photons/mm{sup 2}/mrad{sup 2}/s/0.1%bandwidth, measured at 478 keV. Additional measurements of the flux as a function of the timing difference between the drive laser pulse and the relativistic photoelectron bunch, {gamma}-ray beam profile, and background evaluations are presented. These results are systematically compared to theoretical models and computer simulations. NRF measurements performed on {sup 7}Li in LiH demonstrate the potential of Compton scattering photon sources to accurately detect isotopes in situ.
Date: June 30, 2009
Creator: Albert, F.; Anderson, S. G.; Gibson, D. J.; Hagmann, C. A.; Johnson, M. S.; Messerly, M. et al.
System: The UNT Digital Library
Electronic structure of the BaFe2As2 family of iron-pnictide superconductors (open access)

Electronic structure of the BaFe2As2 family of iron-pnictide superconductors

We use high-resolution angle-resolved photoemission to study the electronic structure of the BaFe{sub 2}As{sub 2} pnictides. We observe two electron bands and two hole bands near the X point, ({pi},{pi}) of the Brillouin zone, in the paramagnetic state for electron-doped Ba(Co{sub 0.06}Fe{sub 0.94}){sub 2}As{sub 2}, undoped BaFe{sub 2}As{sub 2}, and hole-doped Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2}. Among these bands, only the electron bands cross the Fermi level, forming two electron pockets around X while the hole bands approach but never reach the Fermi level. We show that the band structure of the BaFe{sub 2}As{sub 2} family matches reasonably well with the prediction of local-density approximation calculations after a momentum-dependent shift and renormalization. Our finding resolves a number of inconsistencies regarding the electronic structure of pnictides.
Date: June 29, 2009
Creator: Reza, Adriana; Lu, D.H.; Analytis, J.G.; Chu, J.-H.; Mo, S.-K.; He, R.-H. et al.
System: The UNT Digital Library
Modeling Flow Past a Tilted Vena Cava Filter (open access)

Modeling Flow Past a Tilted Vena Cava Filter

Inferior vena cava filters are medical devices used to prevent pulmonary embolism (PE) from deep vein thrombosis. In particular, retrievable filters are well-suited for patients who are unresponsive to anticoagulation therapy and whose risk of PE decreased with time. The goal of this work is to use computational fluid dynamics to evaluate the flow past an unoccluded and partially occluded Celect inferior vena cava filter. In particular, the hemodynamic response to thrombus volume and filter tilt is examined, and the results are compared with flow conditions that are known to be thrombogenic. A computer model of the filter inside a model vena cava is constructed using high resolution digital photographs and methods of computer aided design. The models are parameterized using the Overture software framework, and a collection of overlapping grids is constructed to discretize the flow domain. The incompressible Navier-Stokes equations are solved, and the characteristics of the flow (i.e., velocity contours and wall shear stresses) are computed. The volume of stagnant and recirculating flow increases with thrombus volume. In addition, as the filter increases tilt, the cava wall adjacent to the tilted filter is subjected to low velocity flow that gives rise to regions of low wall shear …
Date: June 29, 2009
Creator: Singer, M. A. & Wang, S. L.
System: The UNT Digital Library
Nuclear Resonance Fluorescence for Materials Assay (open access)

Nuclear Resonance Fluorescence for Materials Assay

This paper discusses the use of nuclear resonance fluorescence (NRF) techniques for the isotopic and quantitative assaying of radioactive material. Potential applications include age-dating of an unknown radioactive source, pre- and post-detonation nuclear forensics, and safeguards for nuclear fuel cycles Examples of age-dating a strong radioactive source and assaying a spent fuel pin are discussed. The modeling work has ben performed with the Monte Carlo radiation transport computer code MCNPX, and the capability to simulate NRF has bee added to the code. Discussed are the limitations in MCNPX?s photon transport physics for accurately describing photon scattering processes that are important contributions to the background and impact the applicability of the NRF assay technique.
Date: June 29, 2009
Creator: Quiter, Brian J.; Ludewigt, Bernhard; Mozin, Vladimir & Prussin, Stanley
System: The UNT Digital Library
Ultrafast Mid-Infrared Intra-Excitonic Response of Individualized Single-Walled Carbon Nanotubes (open access)

Ultrafast Mid-Infrared Intra-Excitonic Response of Individualized Single-Walled Carbon Nanotubes

The quasi-1D confinement and reduced screening of photoexcited charges in single-walled carbon nanotubes (SWNTs) entails strongly-enhanced Coulomb interactions and exciton binding energies. Such amplified electron-hole (e-h) correlations have important implications for both fundamental physics and optoelectronic applications of nanotubes. The availability of"individualized" SWNT ensembles with bright and structured luminescence has rendered specific tube chiralities experimentally accessible. In these samples, evidence for excitonic behavior was found in absorption-luminescence maps, two-photon excited luminescence, or ultrafast carrier dynamics. Here, we report ultrafast mid-infrared (mid-IR) studies of individualized SWNTs, evidencing strong photoinduced absorption around 200 meV in semiconducting tubes of (6,5) and (7,5) chiralities. This manifests the observation of quasi-1D intra-excitonic transitions between different relative-momentum states, in agreement with the binding energy and calculated oscillator strength. Our measurements further reveal a saturation of the photoinduced absorption with increasing phase-space filling of the correlated e-h pairs. The transient mid-IR response represents a new tool, unhindered by restrictions of momentum or interband dipole moment, to investigate the density and dynamics of SWNT excitons.
Date: June 29, 2009
Creator: Wang, Jigang; Graham, Matt W.; Ma, Yingzhong; Fleming, Graham R. & Kaindl, Robert A.
System: The UNT Digital Library
Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles (open access)

Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles

This paper provides new regression models for demand reduction of Demand Response programs for the purpose of ex ante evaluation of the programs and screening for recruiting customer enrollment into the programs. The proposed regression models employ load sensitivity to outside air temperature and representative load pattern derived from cluster analysis of customer baseline load as explanatory variables. The proposed models examined their performances from the viewpoint of validity of explanatory variables and fitness of regressions, using actual load profile data of Pacific Gas and Electric Company's commercial and industrial customers who participated in the 2008 Critical Peak Pricing program including Manual and Automated Demand Response.
Date: June 28, 2009
Creator: Yamaguchi, Nobuyuki; Han, Junqiao; Ghatikar, Girish; Piette, Mary Ann; Asano, Hiroshi & Kiliccote, Sila
System: The UNT Digital Library
AGING AND SURVEILLANCE OF VITON GLT O-RINGS IN MODEL 9975 SHIPPING PACKAGES (open access)

AGING AND SURVEILLANCE OF VITON GLT O-RINGS IN MODEL 9975 SHIPPING PACKAGES

Radioactive material packages (DOT Type B) such as the Model 9975 are used to transport Pu-bearing materials. The 9975 package provides double payload containment via nested stainless steel primary (PCV) and secondary (SCV) containment vessels. The containment vessels are closed by a conical plug sealed with dual O-rings (Figure 1) made of Parker Seals compound V0835-75, based on Viton{reg_sign} GLT fluoroelastomer. The outer O-ring is credited as being leaktight per ANSI N14.5 with a leak rate of <1E-07 ref cc/sec. The 9975 package is being used for interim storage in the K-Area Material Storage (KAMS) facility at the Savannah River Site. The aging performance of the O-rings is being studied to provide the storage facility a technical basis for service life prediction and safety analysis.
Date: June 26, 2009
Creator: Skidmore, T. E.; Hoffman, E. N.; Daugherty, W. L. & Dunn, K. A.
System: The UNT Digital Library
Analysis of High-Te Plasmas Heated by HHFW in NSTX (open access)

Analysis of High-Te Plasmas Heated by HHFW in NSTX

The implementation in TRANSP of a recent version of TORIC capable of calculating power deposition for HHFW conditions is used to analyze NSTX plasma under different operating conditions. The power deposition profile into the electrons is obtained for high-Te conditions - Te ≤ 5keV - obtained in He and D plasmas with ITB. HHFW heating of NBI-induced H-mode plasmas is discussed. At the RF onset the RF power is divided evenly between the electrons and the fast particles, but as the latter thermalize and the electron density increases, the HHFW power repartition shifts progressively toward the electrons. Power deposition profiles for the electrons and for the fast particles are shown.
Date: June 26, 2009
Creator: LeBlanc, P.; Bell, R. E.; Bonoli, P.; Hosea, J. C.; Mazzucato, E.; Phillips, C. K. et al.
System: The UNT Digital Library
INNOVATIVE APPROACHES TO COMPLYING WITH VERY LOW NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT LIMITS FOR METALS (open access)

INNOVATIVE APPROACHES TO COMPLYING WITH VERY LOW NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT LIMITS FOR METALS

The NPDES permit issued to the Savannah River Site (SRS) in 2003 contained very low metals limits for several outfalls. Copper, lead and zinc limits were as low as seven micrograms per liter (7 ug/l), 1 ug/l, and 100 ug/l, respectively. The permit contained compliance schedules that provided SRS with only three to five years to select and implement projects that would enable outfall compliance. Discharges from a few outfalls were eliminated or routed into other locations relatively inexpensively. However, some outfall problems were much more difficult to correct. SRS personnel implemented several innovative projects in order to meet compliance schedule deadlines as inexpensively as possible. These innovations included (1) connecting several outfall discharges to the site's Central Sanitary Wastewater Treatment Facility (CSWTF), (2) constructing a treatment wetlands and completing a water-effects ratio (WER) on its effluent, (3) installing a stannous chloride feed system to remove mercury in an existing air stripper, and (4) constructing a humic acid feed system to increase effluent dissolved organic carbon (DOC) content and take advantage of biotic ligand modeling to raise effluent limits.
Date: June 26, 2009
Creator: Payne, B
System: The UNT Digital Library
Investigations of Magnetic Overlayers at the Advanced Photon Source (open access)

Investigations of Magnetic Overlayers at the Advanced Photon Source

Magnetic overlayers of Fe and Co have been investigated with X-ray Magnetic Circular Dichroism in X-ray Absorption Spectroscopy (XMCD-ABS) and Photoelectron Spectroscopy (PES), including Spin-Resolved Photoelectron Spectroscopy (SRPES), at Beamline 4 at the Advanced Photon Source (APS). Particular emphasis was placed upon the interrogation of the 2p levels of the Fe.
Date: June 26, 2009
Creator: Tobin, J. G.; Yu, S. & Butterfield, M. T.
System: The UNT Digital Library
Recent Improvements in Fast Wave Heating in NSTX (open access)

Recent Improvements in Fast Wave Heating in NSTX

Recent improvements in high-harmonic fast wave (HHFW) core heating in NSTX are attributed to using lithium conditioning, and other wall conditioning techniques, to move the onset density for perpendicular fast wave propagation further from the antenna. This has resulted in the first observation of HHFW core electron heating in deuterium plasma at a launched toroidal wavenumber, kφ = -3 m-1, NSTX record core electron temperatures of 5 keV in helium and deuterium discharges and, for the first time, significant HHFW core electron heating of deuterium neutral-beam-fuelled H-mode plasmas. Also, kφ = -8 m-1 heating of the plasma startup and plasma current ramp-up has resulted in significant core electron heating, even at central electron densities as low as ~ 4x1018 m-3.
Date: June 26, 2009
Creator: G. Taylor, R.E. Bell, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, C.K. Phillips, P.M. Ryan, E.J. Valeo, J.B. Wilgen, J.R. Wilson, and the NSTX Team
System: The UNT Digital Library
The MACHO Project HST Follow-Up: The Large Magellanic Cloud Microlensing Source Stars (open access)

The MACHO Project HST Follow-Up: The Large Magellanic Cloud Microlensing Source Stars

We present Hubble Space Telescope (HST) WFPC2 photometry of 13 microlensed source stars from the 5.7 year Large Magellanic Cloud (LMC) survey conducted by the MACHO Project. The microlensing source stars are identified by deriving accurate centroids in the ground-based MACHO images using difference image analysis (DIA) and then transforming the DIA coordinates to the HST frame. None of these sources is coincident with a background galaxy, which rules out the possibility that the MACHO LMC microlensing sample is contaminated with misidentified supernovae or AGN in galaxies behind the LMC. This supports the conclusion that the MACHO LMC microlensing sample has only a small amount of contamination due to non-microlensing forms of variability. We compare the WFPC2 source star magnitudes with the lensed flux predictions derived from microlensing fits to the light curve data. In most cases the source star brightness is accurately predicted. Finally, we develop a statistic which constrains the location of the Large Magellanic Cloud (LMC) microlensing source stars with respect to the distributions of stars and dust in the LMC and compare this to the predictions of various models of LMC microlensing. This test excludes at {approx}> 90% confidence level models where more than 80% of …
Date: June 25, 2009
Creator: Nelson, C. A.; Drake, A. J.; Cook, K. H.; Bennett, D. P.; Popowski, P.; Dalal, N. et al.
System: The UNT Digital Library
Measurement of the angle alpha at BABAR (open access)

Measurement of the angle alpha at BABAR

The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.
Date: June 25, 2009
Creator: Perez, A.
System: The UNT Digital Library
NEW APPROACH TO ADDRESSING GAS GENERATION IN RADIOACTIVE MATERIAL PACKAGING (open access)

NEW APPROACH TO ADDRESSING GAS GENERATION IN RADIOACTIVE MATERIAL PACKAGING

Safety Analysis Reports for Packaging (SARP) document why the transportation of radioactive material is safe in Type A(F) and Type B shipping containers. The content evaluation of certain actinide materials require that the gas generation characteristics be addressed. Most packages used to transport actinides impose extremely restrictive limits on moisture content and oxide stabilization to control or prevent flammable gas generation. These requirements prevent some users from using a shipping container even though the material to be shipped is fully compliant with the remaining content envelope including isotopic distribution. To avoid these restrictions, gas generation issues have to be addressed on a case by case basis rather than a one size fits all approach. In addition, SARP applicants and review groups may not have the knowledge and experience with actinide chemistry and other factors affecting gas generation, which facility experts in actinide material processing have obtained in the last sixty years. This paper will address a proposal to create a Gas Generation Evaluation Committee to evaluate gas generation issues associated with Safety Analysis Reports for Packaging material contents. The committee charter could include reviews of both SARP approved contents and new contents not previously evaluated in a SARP.
Date: June 25, 2009
Creator: Watkins, R; Leduc, D & Askew, N
System: The UNT Digital Library
Recent Results From BaBar in Tau Physics (open access)

Recent Results From BaBar in Tau Physics

The BaBar collaboration has accumulated over 400 million {tau}-pairs which can be used to study charged leptonic and hadronic weak currents to unprecedented precision. This note presents results on lepton universality, measurements of |V{sub us}|, and searches for {tau} decays which violate lepton flavour conservation, or {tau} decays that proceed through a suppressed second class current.
Date: June 25, 2009
Creator: Lewczuk, Mateusz
System: The UNT Digital Library