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Technical Risk Rating of DOE Environmental Projects - 9153 (open access)

Technical Risk Rating of DOE Environmental Projects - 9153

The U.S. Department of Energy's Office of Environmental Management (DOE-EM) was established to achieve the safe and compliant disposition of legacy wastes and facilities from defense nuclear applications. The scope of work is diverse, with projects ranging from single acquisitions to collections of projects and operations that span several decades and costs from hundreds of millions to billions US$. The need to be able to manage and understand the technical risks from the project to senior management level has been recognized as an enabler to successfully completing the mission. In 2008, DOE-EM developed the Technical Risk Rating as a new method to assist in managing technical risk based on specific criteria. The Technical Risk Rating, and the criteria used to determine the rating, provides a mechanism to foster open, meaningful communication between the Federal Project Directors and DOE-EM management concerning project technical risks. Four indicators (technical maturity, risk urgency, handling difficulty and resolution path) are used to focus attention on the issues and key aspects related to the risks. Pressing risk issues are brought to the forefront, keeping DOE-EM management informed and engaged such that they fully understand risk impact. Use of the Technical Risk Rating and criteria during reviews …
Date: February 11, 2009
Creator: Cercy, Michael; Fayfich, Ronald & Schneider, Steven
System: The UNT Digital Library
ON THE IMPACT OF SUPER RESOLUTION WSR-88D DOPPLER RADAR DATA ASSIMILATION ON HIGH RESOLUTION NUMERICAL MODEL FORECASTS (open access)

ON THE IMPACT OF SUPER RESOLUTION WSR-88D DOPPLER RADAR DATA ASSIMILATION ON HIGH RESOLUTION NUMERICAL MODEL FORECASTS

Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale …
Date: January 11, 2009
Creator: Chiswell, S
System: The UNT Digital Library
Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter (open access)

Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter

One method for disposition of excess plutonium is vitrification into cylindrical wasteforms. Due to the hazards of working with plutonium, the vitrification process must be carried out remotely in a shielded environment. Thus, the equipment must be easily maintained. With their simple design, induction melters satisfy this criterion, making them ideal candidates for plutonium vitrification. However, due to repeated heating and cooling cycles and differences in coefficients of thermal expansion of contacting materials fatigue failure of the induction melter is of concern. Due to the cost of the melter, the number of cycles to failure is critical. This paper presents a method for determining the cycles to failure for an induction melter by using the results from thermal and structural analyses as input to a fatigue failure model.
Date: February 11, 2009
Creator: Jordan, Jeffrey & Gorczyca, Jennifer
System: The UNT Digital Library
Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks (open access)

Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks

At the Savannah River Site (SRS) there are 49 High Level Waste (HLW) tanks that eventually must be emptied, cleaned, and closed. The current method of chemically cleaning SRS HLW tanks, commonly referred to as Bulk Oxalic Acid Cleaning (BOAC), requires about a half million liters (130,000 gallons) of 8 weight percent (wt%) oxalic acid to clean a single tank. During the cleaning, the oxalic acid acts as the solvent to digest sludge solids and insoluble salt solids, such that they can be suspended and pumped out of the tank. Because of the volume and concentration of acid used, a significant quantity of oxalate is added to the HLW process. This added oxalate significantly impacts downstream processing. In addition to the oxalate, the volume of liquid added competes for the limited available tank space. A search, therefore, was initiated for a new cleaning process. Using TRIZ (Teoriya Resheniya Izobretatelskikh Zadatch or roughly translated as the Theory of Inventive Problem Solving), Chemical Oxidation Reduction Decontamination with Ultraviolet Light (CORD-UV{reg_sign}), a mature technology used in the commercial nuclear power industry was identified as an alternate technology. Similar to BOAC, CORD-UV{reg_sign} also uses oxalic acid as the solvent to dissolve the metal (hydr)oxide …
Date: February 11, 2009
Creator: Ketusky, Edward; Spires, Renee & Davis, Neil
System: The UNT Digital Library
Salt Processing Through Ion Exchange at the Savannah River Site Selection of Exchange Media and Column Configuration - 9198 (open access)

Salt Processing Through Ion Exchange at the Savannah River Site Selection of Exchange Media and Column Configuration - 9198

The Department of Energy (DOE) has developed, modeled, and tested several different ion exchange media and column designs for cesium removal. One elutable resin and one non-elutable resin were considered for this salt processing application. Deployment of non-elutable Crystalline Silicotitanate and elutable Resorcinol Formaldehyde in several different column configurations were assessed in a formal Systems Engineering Evaluation (SEE). Salt solutions were selected that would allow a grouping of non-compliant tanks to be closed. Tests were run with the elutable resin to determine compatibility with the resin configuration required for an in-tank ion exchange system. Models were run to estimate the ion exchange cycles required with the two resins in several column configurations. Material balance calculations were performed to estimate the impact on the High Level Waste (HLW) system at the Savannah River Site (SRS). Conceptual process diagrams were used to support the hazard analysis. Data from the hazard analysis was used to determine the relative impact on safety. This report will discuss the technical inputs, SEE methods, results and path forward to complete the technical maturation of ion exchange.
Date: February 11, 2009
Creator: Spires, Renee; Punch, Timothy & McCabe, Daniel
System: The UNT Digital Library
Peroxotitanates for Biodelivery of Metals (open access)

Peroxotitanates for Biodelivery of Metals

Metal-based drugs are largely undeveloped in pharmacology. One limiting factor is the systemic toxicity of metal-based compounds. A solid-phase, sequestratable delivery agent for local delivery of metals could reduce systemic toxicity, facilitating new drug development in this nascent area. Amorphous peroxotitanates (APT) are ion exchange materials with high affinity for several heavy metal ions, and have been proposed to deliver or sequester metal ions in biological contexts. In the current study, we tested a hypothesis that APT are able to deliver metals or metal compounds to cells. We exposed fibroblasts (L929) or monocytes (THP1) to metal-APT materials for 72 h in vitro, then measured cellular mitochondrial activity (SDH-MTT method) to assess the biological impact of the metal-APT materials vs. metals or APT alone. APT alone did not significantly affect cellular mitochondrial activity, but all metal-APT materials suppressed the mitochondrial activity of fibroblasts (by 30-65% of controls). The concentration of metal-APT materials required to suppress cellular mitochondrial activity was below that required for metals alone, suggesting that simple extracellular release of the metals from the metal-APT materials was not the primary mechanism of mitochondrial suppression. In contrast to fibroblasts, no metal-APT material had a measurable effect on THP1 monocyte mitochondrial activity, …
Date: February 11, 2009
Creator: Hobbs, David & Elvington, M.
System: The UNT Digital Library
ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION (open access)

ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided …
Date: June 11, 2009
Creator: Gorensek, M. & Edwards, T.
System: The UNT Digital Library
Indirect Determination of the 230Th(n,f) and 231Th(n,f) Cross Sections for Thorium-Based Nuclear Energy Systems (open access)

Indirect Determination of the 230Th(n,f) and 231Th(n,f) Cross Sections for Thorium-Based Nuclear Energy Systems

The Surrogate Ratio Method (SRM) was employed in the first experimental determination of the 231Th(n,f) cross section, relative to the 235U(n,f) cross section, over an equivalent neutron energy range of 360 keV to 10 MeV. The 230Th(n,f) cross section was also deduced using the SRM, relative to the 234U(n,f) cross section, over an equivalent neutron energy range of 220 keV to 25 MeV. The desired compound nuclei were populated using (3He,3He) and (3He) reactions on targets of 232Th and 236U and relative fission decay probabilities were measured. The surrogate 230,231Th(n,f) cross sections were compared to cross section evaluations and directly-measured experimental data, where available.
Date: September 11, 2009
Creator: Stroberg, S.R.; Allmond, J.M.; Angell, C.; Bernstein, L.A.; Bleuel, D.L.; Burke, J.T. et al.
System: The UNT Digital Library
Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair (open access)

Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair

The three human LIG genes encode polypeptides that catalyze phosphodiester bond formation during DNA replication, recombination and repair. While numerous studies have identified protein partners of the human DNA ligases (hLigs), there has been little characterization of the catalytic properties of these enzymes. In this study, we developed and optimized a fluorescence-based DNA ligation assay to characterize the activities of purified hLigs. Although hLigI joins DNA nicks, it has no detectable activity on linear duplex DNA substrates with short, cohesive single-strand ends. By contrast, hLigIII{beta} and the hLigIII{alpha}/XRCC1 and hLigIV/XRCC4 complexes are active on both nicked and linear duplex DNA substrates. Surprisingly, hLigIV/XRCC4, which is a key component of the major non-homologous end joining (NHEJ) pathway, is significantly less active than hLigIII on a linear duplex DNA substrate. Notably, hLigIV/XRCC4 molecules only catalyze a single ligation event in the absence or presence of ATP. The failure to catalyze subsequent ligation events reflects a defect in the enzyme-adenylation step of the next ligation reaction and suggests that, unless there is an in vivo mechanism to reactivate DNA ligase IV/XRCC4 following phosphodiester bond formation, the cellular NHEJ capacity will be determined by the number of adenylated DNA ligaseIV/XRCC4 molecules.
Date: May 11, 2009
Creator: Chen, Xi; Ballin, Jeff D.; Della-Maria, Julie; Tsai, Miaw-Sheue; White, Elizabeth J.; Tomkinson, Alan E. et al.
System: The UNT Digital Library
A Novel Demountable TF Joint Design for Low Aspect Ratio Spherical Torus Tokamaks (open access)

A Novel Demountable TF Joint Design for Low Aspect Ratio Spherical Torus Tokamaks

A novel shaped design for the radial conductors and demountable electrical joints connecting inner and outer legs of copper TF system conductors in low aspect ratio tokamaks is described and analysis results are presented. Specially shaped designs can optimize profiles of electrical current density, magnetic force, heating, and mechanical stress.
Date: June 11, 2009
Creator: Woolley, Robert D.
System: The UNT Digital Library
Using Atom Interferometry to Search for New Forces (open access)

Using Atom Interferometry to Search for New Forces

Atom interferometry is a rapidly advancing field and this Letter proposes an experiment based on existing technology that can search for new short distance forces. With current technology it is possible to improve the sensitivity by up to a factor of 10{sup 2} and near-future advances will be able to rewrite the limits for forces with ranges from 100 {micro}m to 1km.
Date: December 11, 2009
Creator: Wacker, Jay G.
System: The UNT Digital Library
On Soft Sngularities at Three Loops and Beyond (open access)

On Soft Sngularities at Three Loops and Beyond

We report on further progress in understanding soft singularities of massless gauge theory scattering amplitudes. Recently, a set of equations was derived based on Sudakov factorization, constraining the soft anomalous dimension matrix of multi-leg scattering amplitudes to any loop order, and relating it to the cusp anomalous dimension. The minimal solution to these equations was shown to be a sum over color dipoles. Here we explore potential contributions to the soft anomalous dimension that go beyond the sum-over-dipoles formula. Such contributions are constrained by factorization and invariance under rescaling of parton momenta to be functions of conformally invariant cross ratios. Therefore, they must correlate the color and kinematic degrees of freedom of at least four hard partons, corresponding to gluon webs that connect four eikonal lines, which first appear at three loops. We analyze potential contributions, combining all available constraints, including Bose symmetry, the expected degree of transcendentality, and the singularity structure in the limit where two hard partons become collinear. We find that if the kinematic dependence is solely through products of logarithms of cross ratios, then at three loops there is a unique function that is consistent with all available constraints. If polylogarithms are allowed to appear as …
Date: December 11, 2009
Creator: Dixon, Lance J.; Gardi, Einan. & Magnea, Lorenzo.
System: The UNT Digital Library
XAL Adoption Experience at LCLS (open access)

XAL Adoption Experience at LCLS

XAL is a high level accelerator application framework originally developed by the Spallation Neutron Source (SNS), Oak Ridge National Laboratory. The XAL framework provides generic hierarchical view for an accelerator as well as many utility tools. In XAL, a built-in physics model calculates either single particle or beam envelope tracking for physics parameters. Modifications to the original XAL model are necessary for the Linac Coherent Light Source (LCLS). Work was done to manipulate MAD deck output within a database in support of the XAL configuration and model. The XAL graphical user interface has been replaced by a SLAC specific design. New applications based on the framework are also discussed in this paper.
Date: December 11, 2009
Creator: Chu, P.; Woodley, M.; Chan, A.; Chevtsov, S.; Fairley, D.; Grunhaus, E. et al.
System: The UNT Digital Library
Near Edge X-Ray Absorption Fine Structure Spectroscopy with X-Ray Free-Electron Lasers (open access)

Near Edge X-Ray Absorption Fine Structure Spectroscopy with X-Ray Free-Electron Lasers

We demonstrate the feasibility of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy on solids by means of femtosecond soft x-ray pulses from a free-electron laser (FEL). Our experiments, carried out at the Free-Electron Laser at Hamburg (FLASH), used a special sample geometry, spectrographic energy dispersion, single shot position-sensitive detection and a data normalization procedure that eliminates the severe fluctuations of the incident intensity in space and photon energy. As an example we recorded the {sup 3}D{sub 1} N{sub 4,5}-edge absorption resonance of La{sup 3+}-ions in LaMnO{sub 3}. Our study opens the door for x-ray absorption measurements on future x-ray FEL facilities.
Date: December 11, 2009
Creator: Bernstein, D.P.; Acremann, Y.; Scherz, A.; Burkhardt, M.; Stohr, J.; Beye, M. et al.
System: The UNT Digital Library
Transverse momentum dependent quark distributions and polarized Drell-Yan processes (open access)

Transverse momentum dependent quark distributions and polarized Drell-Yan processes

We study the spin-dependent quark distributions at large transverse momentum. We derive their transverse momentum behaviors in the collinear factorization approach in this region. We further calculate the angular distribution of the Drell-Yan lepton pair production with polarized beams and present the results in terms of the collinear twist-three quark-gluon correlation functions. In the intermediate transverse momentum region, we find that the two pproaches: the collinear factorization and the transverse momentum dependent factorization approaches are consistent in the description of the lepton pair angular distributions.
Date: September 11, 2009
Creator: Zhou, J.; Yuan, F. & Liang, Z.-T.
System: The UNT Digital Library
Millikelvin thermal and electrical performance of lossy transmission line filters (open access)

Millikelvin thermal and electrical performance of lossy transmission line filters

We report on the scattering parameters and Johnson noise emission of low-pass stripline filters employing a magnetically loaded silicone dielectric down to 25 mK. The transmission characteristic of a device with f-3dB=1.3 GHz remains essentially unchanged upon cooling. Another device with f-edB=0.4 GHz, measured in its stopband, exhibits a steady state noise power emission consistent with a temperature difference of a few mK relative to a well-anchored cryogenic microwave attenuator at temperatures down to 25 mK, thus presenting a matched thermal load.
Date: March 11, 2009
Creator: Slichter, Daniel; Naaman, Ofer & Siddiqi, Irfan
System: The UNT Digital Library
Lessons Learned in Risk Management on NCSX (open access)

Lessons Learned in Risk Management on NCSX

The National Compact Stellarator Experiment (NCSX) was designed to test physics principles of an innovative stellarator design developed by the Princeton Plasma Physics Laboratory and Oak Ridge National Laboratory. Construction of some of the major components and sub-assemblies was completed, but the estimated cost and schedule for completing the project grew as the technical requirements and risks became better understood, leading to its cancellation in 2008. The project's risks stemmed from its technical challenges, primarily the complex component geometries and tight tolerances that were required. The initial baseline, established in 2004, was supported by a risk management plan and risk-based contingencies, both of which proved to be inadequate. Technical successes were achieved in the construction of challenging components and subassemblies, but cost and schedule growth was experienced. As part of an effort to improve project performance, a new risk management program was devised and implemented in 2007-08. It led to a better understanding of project risks, a sounder basis for contingency estimates, and improved management tools. Although the risks ultimately were unacceptable to the sponsor, valuable lessons in risk management were learned through the experiences with the NCSX project.
Date: February 11, 2009
Creator: G.H. Neilson, C.O. Gruber, J.H. Harris, D.J. Rej, R.T. Simmons, and R.L. Strykowsky
System: The UNT Digital Library
PROJECTED IMPACT OF SULFATE ATTACK ON THE LONG-TERM PERFORMANCE OF A CONCRETE REPOSITORY (open access)

PROJECTED IMPACT OF SULFATE ATTACK ON THE LONG-TERM PERFORMANCE OF A CONCRETE REPOSITORY

Saltstone is a cementitious waste form made by mixing salt solution originating from liquid waste storage tanks at the DOE Savannah River Site with a dry mix containing blast furnace slag, fly ash, and cement or lime. The wet mix is poured into a concrete repository for on-site disposal. Solidified Saltstone is a dense, alkaline, reducing, micro-porous, monolithic, cementitious matrix, containing a solution of salts within its pore structure. Sodium sulfate concentrations in the pore fluid are around 0.15 mol/L, and external sulfate attack on concrete barriers is expected to occur over time. To predict the long-term performance of concrete repositories, the STADIUM{reg_sign} code was used to simulate the reactive transport processes leading to formation of ettringite, an expansive mineral phase often associated with spalling or cracking. STADIUM{reg_sign} is a multi-ionic transport model based on a split operator approach that separates ionic movement and chemical reactions. Ionic transport is described by the extended Nernst-Planck equation for unsaturated media, and accounts for electrical coupling between ionic species, chemical activity, transport due to water content gradient, and temperature effects. STADIUM{reg_sign} does not predict whether physical damage will occur, or the impact on transport properties should fracturing occur. Thus the presence of ettringite …
Date: December 11, 2009
Creator: Flach, G.
System: The UNT Digital Library
Spectral Effects on Fast Wave Core Heating and Current Drive (open access)

Spectral Effects on Fast Wave Core Heating and Current Drive

Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effect …
Date: May 11, 2009
Creator: C.K. Phillips, R.E. Bell, L.A. Berry, P.T. Bonoli, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, P.M. Ryan, G. Taylor, E.J. Valeo, J.R. Wilson, J.C. Wright, H. Yuh, and the NSTX Team
System: The UNT Digital Library
XAL-Based Applications and Online Models for LCLS (open access)

XAL-Based Applications and Online Models for LCLS

XAL, a high-level accelerator application framework originally developed at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory, has been adopted by the Linac Coherent Light Source (LCLS) project. The work includes proper relational database schema modification to better suit XAL configuration data requirement, addition of new device types for LCLS online modeling purpose, longitudinal coordinate system change to better represent the LCLS electron beam rather than proton or ion beam in the original SNS XAL design, intensively benchmark with MAD and present SLC modeling system for the online model, and various new features to the XAL framework. Storing online model data in a relational database and providing universal access methods for other applications is also described here.
Date: December 11, 2009
Creator: Chu, P.; Woodley, M.; Iverson, R.; Krejcik, P.; White, G.; Wu, J. et al.
System: The UNT Digital Library
A Markov Model for Assessing the Reliability of a Digital Feedwater Control System (open access)

A Markov Model for Assessing the Reliability of a Digital Feedwater Control System

A Markov approach has been selected to represent and quantify the reliability model of a digital feedwater control system (DFWCS). The system state, i.e., whether a system fails or not, is determined by the status of the components that can be characterized by component failure modes. Starting from the system state that has no component failure, possible transitions out of it are all failure modes of all components in the system. Each additional component failure mode will formulate a different system state that may or may not be a system failure state. The Markov transition diagram is developed by strictly following the sequences of component failures (i.e., failure sequences) because the different orders of the same set of failures may affect the system in completely different ways. The formulation and quantification of the Markov model, together with the proposed FMEA (Failure Modes and Effects Analysis) approach, and the development of the supporting automated FMEA tool are considered the three major elements of a generic conceptual framework under which the reliability of digital systems can be assessed.
Date: February 11, 2009
Creator: Chu, T. L.; Yue, M.; Martinez-Guridi, G. & Lehner, J.
System: The UNT Digital Library
Dissecting the Gravitational Lens B1608 656. II. Precision Measurements of the Hubble Constant, Spatial Curvature, and the Dark Energy Equation of State (open access)

Dissecting the Gravitational Lens B1608 656. II. Precision Measurements of the Hubble Constant, Spatial Curvature, and the Dark Energy Equation of State

Strong gravitational lens systems with measured time delays between the multiple images provide a method for measuring the 'time-delay distance' to the lens, and thus the Hubble constant. We present a Bayesian analysis of the strong gravitational lens system B1608+656, incorporating (1) new, deep Hubble Space Telescope (HST) observations, (2) a new velocity dispersion measurement of 260 {+-} 15 km s{sup -1} for the primary lens galaxy, and (3) an updated study of the lens environment. Our analysis of the HST images takes into account the extended source surface brightness, and the dust extinction and optical emission by the interacting lens galaxies. When modeling the stellar dynamics of the primary lens galaxy, the lensing effect, and the environment of the lens, we explicitly include the total mass distribution profile logarithmic slope {gamma}{prime} and the external convergence {kappa}{sub ext}; we marginalize over these parameters, assigning well-motivated priors for them, and so turn the major systematic errors into statistical ones. The HST images provide one such prior, constraining the lens mass density profile logarithmic slope to be {gamma}{prime} = 2.08 {+-} 0.03; a combination of numerical simulations and photometric observations of the B1608+656 field provides an estimate of the prior for {kappa}{sub …
Date: December 11, 2009
Creator: Suyu, S. H.; Marshall, P. J.; Auger, M. W.; Hilbert, S.; Blandford, R. D.; Koopmans, L. V. E. et al.
System: The UNT Digital Library
MINING INTEGRAL ACTINIDES CROSS SECTIONS FROM REACTOR DATA (open access)

MINING INTEGRAL ACTINIDES CROSS SECTIONS FROM REACTOR DATA

The conclusions of this paper are: (1) mining of actinide cross-sections from reactor data is a viable and inexpensive approach to confirm burn-up codes; (2) extensive data for actinides in Hanford test data ({approx} 200 radiochemical analyses); (3) not only cross-section values and reaction rates can be established but also possible benchmark like data can be constructed to test and validate reactor and criticality safety codes such as SCALE/KENO or MCNPX; and (4) analysis along multiple transmutation paths can be evaluated to show consistency.
Date: September 11, 2009
Creator: RJ, PUIGH
System: The UNT Digital Library
Measurements of Time-Dependent CP Violation in Radiative B Decays at BaBar (open access)

Measurements of Time-Dependent CP Violation in Radiative B Decays at BaBar

The authors present measurements of the CP-violation parameters S and C for the radiative decays B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}{gamma} and B{sup 0} {yields} {eta}K{sub S}{sup 0}{gamma}; for B {yields} {eta}K{gamma} they also measure the branching fractions and for B{sup +} {yields} {eta}K{sup +}{gamma} the time-integrated charge asymmetry A{sub ch}. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represent 467 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation at the PEP-II collider. In this summary they present an updated measurement of the time-dependent CP asymmetry in B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}{gamma} decay mode and the first measurement of the time-dependent CP asymmetry in B{sup 0} {yields} {eta}K{sub S}{sup 0}{gamma} decay mode. Hadronic corrections in B{sup 0} {yields} {pi}{sup 0}K{sub S}{sup 0}{gamma} decay mode might permit S to be as large as {+-} 0.1. Such corrections and NP effects could depend on m({pi}{sup 0}K{sub S}{sup 0}), so they split the data into two parts: the K*(892) region with 0.8 < m({pi}{sup 0}K{sub S}{sup 0}) < 1.0 GeV/c{sup 2} and the non-K*(892) region with 1.1 < m({pi}{sup 0}K{sub S}{sup 0}) < 1.8 GeV/c{sup 2}. They also report updated measurements …
Date: December 11, 2009
Creator: Lazzaro, A.
System: The UNT Digital Library