B, D and K Decays (open access)

B, D and K Decays

The present report documents the results of Working Group 2: B, D and K decays, of the workshop on Flavor in the Era of the LHC, held at CERN from November 2005 through March 2007. With the advent of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavor physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC. The aim of Working Group 2 was twofold: on one hand, to provide a coherent, up-to-date picture of the status of flavor physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP …
Date: March 7, 2008
Creator: Artuso, M.; Asner, D. M.; Ball, P.; Baracchini, E.; Bell, G.; Beneke, M. et al.
System: The UNT Digital Library
Structures in Molecular Clouds: Modeling (open access)

Structures in Molecular Clouds: Modeling

None
Date: March 7, 2006
Creator: Kane, J. O.; Ryutov, D. D.; Remington, B. A.; Pound, M. & Mizuta, A.
System: The UNT Digital Library
Development and Implementation of an Ergonomics Program for Research Laboratories (open access)

Development and Implementation of an Ergonomics Program for Research Laboratories

None
Date: March 7, 2006
Creator: Roberts, T.; Yu, E. & Herbert, R.
System: The UNT Digital Library
Possible Rhic Upgrades With Superbunches. (open access)

Possible Rhic Upgrades With Superbunches.

None
Date: March 7, 2006
Creator: Fischer, W.; Blaskiewicz, M. & Wei, J.
System: The UNT Digital Library
Applications of Lagrangian Dispersion Modeling to the Analysis of Changes in the Specific Absorption of Elemental Carbon (open access)

Applications of Lagrangian Dispersion Modeling to the Analysis of Changes in the Specific Absorption of Elemental Carbon

We use a Lagrangian dispersion model driven by a mesoscale model with four-dimensional data assimilation to simulate the dispersion of elemental carbon (EC) over a region encompassing Mexico City and its surroundings, the study domain for the 2006 MAX-MEX experiment, which was a component of the MILAGRO campaign. The results are used to identify periods when biomass burning was likely to have had a significant impact on the concentrations of elemental carbon at two sites, T1 and T2, downwind of the city, and when emissions from the Mexico City Metropolitan Area (MCMA) were likely to have been more important. They are also used to estimate the median ages of EC affecting the specific absorption of light, aABS, at 870 nm as well as to identify periods when the urban plume from the MCMA was likely to have been advected over T1 and T2. Values of aABS at T1, the nearer of the two sites to Mexico City, were smaller at night and increased rapidly after mid-morning, peaking in the mid-afternoon. The behavior is attributed to the coating of aerosols with substances such as sulfate or organic carbon during daylight hours, but such coating appears to be limited or absent at …
Date: March 7, 2008
Creator: Doran, J. C.; Fast, Jerome D.; Barnard, James C.; Laskin, Alexander; Desyaterik, Yury; Gilles, Marry K. et al.
System: The UNT Digital Library
Collider Aspects of Flavour Physics at High Q (open access)

Collider Aspects of Flavour Physics at High Q

This chapter of the report of the 'Flavour in the era of LHC' workshop discusses flavor related issues in the production and decays of heavy states at LHC, both from the experimental side and from the theoretical side. We review top quark physics and discuss flavor aspects of several extensions of the Standard Model, such as supersymmetry, little Higgs model or models with extra dimensions. This includes discovery aspects as well as measurement of several properties of these heavy states. We also present public available computational tools related to this topic.
Date: March 7, 2008
Creator: del Aguila, F.; Aguilar-Saavedra, J. A.; Allanach, B. C.; Alwall, J.; Andreev, Yu.; Aristizabal Sierra, D. et al.
System: The UNT Digital Library
Using Higher Order Modes in Superconducting Accelerating Cavities for Beam Monitoring (open access)

Using Higher Order Modes in Superconducting Accelerating Cavities for Beam Monitoring

Dipole modes have been shown to be successful diagnostics for the beam position in superconducting accelerating cavities at the Free Electron Laser in Hamburg (FLASH) facility at DESY. By help of downmixing electronics the signals from the two higher order mode (HOM) couplers mounted on each cavity are monitored. The calibration, based on singular value decomposition, is more complicated than in standard position monitors. Position like signals based on this calibration are currently being in the process of being included in the control system. A second setup based on digitizing the spectrum from the HOM couplers has been used for monitoring monopole modes. The beam phase with respect to the RF has been thus monitored. The position calibration measurements and phase monitoring made at the FLASH are presented.
Date: March 7, 2008
Creator: Molloy, S.; Baboi, N.; Eddy, N.; Frisch, J.; Hendrickson, L.; Hensler, O. et al.
System: The UNT Digital Library
An Implicit "Drift-Lorentz" Particle Mover for Plasma and Beam Simulations (open access)

An Implicit "Drift-Lorentz" Particle Mover for Plasma and Beam Simulations

In order to efficiently perform particle simulations in systems with widely varying magnetization, we have developed a 'drift-Lorentz mover', which interpolates between full particle dynamics and drift kinetics in such a way as to preserve a physically correct gyroradius and particle drifts for both large and small ratios of the timestep to the cyclotron period. In order to extend applicability of the mover to systems with plasma frequency exceeding the cyclotron frequency - such as one may have with fully neutralized drift compression of a heavy ion beam - we have developed an implicit version of the mover. A first step in this direction, in which the polarization charge was added to the field solver, was described previously. Here we describe a fully implicit algorithm (which is analogous to the direct-implicit method for conventional particle-in-cell simulation), a stability analysis of it, its implementation in the WARP code, and several tests of the resultant code. The fully implemented version is electrostatic; we are beginning development of an electromagnetic version, and describe also the status of that effort.
Date: March 7, 2008
Creator: Cohen, R H; Friedman, A; Grote, D P & Vay, J
System: The UNT Digital Library
"Computational Modeling of Actinide Complexes" (open access)

"Computational Modeling of Actinide Complexes"

We will present our recent studies on computational actinide chemistry of complexes which are not only interesting from the standpoint of actinide coordination chemistry but also of relevance to environmental management of high-level nuclear wastes. We will be discussing our recent collaborative efforts with Professor Heino Nitsche of LBNL whose research group has been actively carrying out experimental studies on these species. Computations of actinide complexes are also quintessential to our understanding of the complexes found in geochemical, biochemical environments and actinide chemistry relevant to advanced nuclear systems. In particular we have been studying uranyl, plutonyl, and Cm(III) complexes are in aqueous solution. These studies are made with a variety of relativistic methods such as coupled cluster methods, DFT, and complete active space multi-configuration self-consistent-field (CASSCF) followed by large-scale CI computations and relativistic CI (RCI) computations up to 60 million configurations. Our computational studies on actinide complexes were motivated by ongoing EXAFS studies of speciated complexes in geo and biochemical environments carried out by Prof Heino Nitsche's group at Berkeley, Dr. David Clark at Los Alamos and Dr. Gibson's work on small actinide molecules at ORNL. The hydrolysis reactions of urnayl, neputyl and plutonyl complexes have received considerable attention due …
Date: March 7, 2007
Creator: Balasubramanian, K
System: The UNT Digital Library
Further studies of electron avalanche gain in liquid argon (open access)

Further studies of electron avalanche gain in liquid argon

Previously we showed how small admixtures of xenon (Xe) stabilize electron avalanches in liquid Argon (LAr). In the present work, we have measured the positive charge carrier mobility in LAr with small admixtures of Xe to be 6.4 x 10{sup -3} cm{sup 2}/Vsec, in approximate agreement with the mobility measured in pure LAr, and consistent with holes as charge carriers. We have measured the concentration of Xe actually dissolved in the liquid and compared the results with expectations based on the amount of Xe gas added to the LAr. We also have tested LAr doped with krypton to investigate the mechanism of avalanche stabilization.
Date: March 7, 2003
Creator: Kim, J. G.; Dardin, S. M.; Kadel, R. W.; Kadyk, J. A.; Jackson, K. H.; Peskov, V. et al.
System: The UNT Digital Library
An X-ray Absorption Edge Detector for High-Resolution Measurement of Undulator Effective K-Parameter (open access)

An X-ray Absorption Edge Detector for High-Resolution Measurement of Undulator Effective K-Parameter

The spectrum of angle-integrated undulator radiation displays a sharp edge at every harmonic photon energy. A technique utilizing this feature to measure minute changes in K-parameters of an undulator in a free-electron laser has been proposed. To date, this technique requires the use of crystal monochromators as bandpass filters whose energy centroid depends on the incident angle of the x-ray beam. In this work we propose to use the absorption edge of an appropriate element as an energy-selective detector whose response is truly independent of the angle of the x-ray beam, and hence independent of electron beam direction and emittance. We will discuss the basic design concept of the detection system and illustrate its projected performance with computer simulations.
Date: March 7, 2007
Creator: Yang, B.; /Argonne & Galayda, J.N.
System: The UNT Digital Library
Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey (open access)

Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey

The authors present an analysis of the color and variability characteristics for point sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged {approx} 23 square degrees in BVI filters from {approx} 16-24 mag to investigate variability in faint sources at moderate to high Galactic latitudes. Point source completeness is found to be >83% for a selected representative sample (V - 17.5-22.0 mag, B-V = 0.0-1.5) containing both photometric B, V detections and 80% of the time-sampled V data available compared to a basic internal source completeness of 99%. Multi-epoch (10-30) observations in V spanning minutes to years modeled by light curve simulations reveal amplitude sensitivities to {approx} 0.015-0.075 mag over a representative V = 18-22 mag range. Periodicity determinations appear viable to time-scales of an order 1 day or less using the most sampled fields ({approx} 30 epochs). The fraction of point sources is found to be generally variable at 5-8% over V = 17.5-22.0 mag. For V brighter than 19 mag, the variable population is dominated by low amplitude (< 0.05 mag) and blue (B-V < 0.35) sources, possibly representing a population of {gamma} Doradus stars. Overall, the dominant population of variable sources are bluer than B-V …
Date: March 7, 2005
Creator: Huber, M E; Everett, M E & Howell, S B
System: The UNT Digital Library
Lethality Effects of a High-Power Solid-State Laser (open access)

Lethality Effects of a High-Power Solid-State Laser

We study the material interactions of a 25-kW solid-state laser, in experiments characterized by relatively large spot size sizes ({approx}3 cm) and the presence of airflow. The targets are 1-cm slabs of iron or aluminum. In the experiments with iron, we show that combustion plays an important role in heating the material. In the experiments with aluminum, there is a narrow range of intensities within which the material interactions vary from no melting at all to complete melt-through. A paint layer serves to increase the absorption. We explain these effects and incorporate them into a comprehensive computational model.
Date: March 7, 2007
Creator: Boley, C.; Fochs, S. & Rubenchik, A.
System: The UNT Digital Library
Proof of Principle Experiments That Demonstrate Utility of Cocktail Hohlraums for Indirect Drive Ignition (open access)

Proof of Principle Experiments That Demonstrate Utility of Cocktail Hohlraums for Indirect Drive Ignition

None
Date: March 7, 2007
Creator: Jones, O. S.; Schein, J.; Rosen, M.. D.; Suter, L. J.; Wallace, R. J.; Dewald, E. L. et al.
System: The UNT Digital Library
Antimicrobial Properties of Diamondlike Carbon-Silver-Platinum Nanocomposite Thin Films (open access)

Antimicrobial Properties of Diamondlike Carbon-Silver-Platinum Nanocomposite Thin Films

Silver and platinum were incorporated within diamondlike carbon (DLC) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films reveals that the metals self-assemble into particulate nanocomposite structures. Nanoindentation testing has shown that diamondlike carbon-silver films exhibit hardness and Young's modulus values of approximately 37 GPa and 333 GPa, respectively. DLC-silver-platinum films exhibited antimicrobial properties against Staphylococcus bacteria. Diamondlike carbon-biofunctional metal nanocomposite films have a variety of potential medical and antimicrobial applications.
Date: March 7, 2005
Creator: CHRISTOPHER, BERRY
System: The UNT Digital Library
Characterization of Microbial Communities in TCE-Contaminated Seep Zone Sediments (open access)

Characterization of Microbial Communities in TCE-Contaminated Seep Zone Sediments

Hundreds of sites across the United States contain trichloroethene (TCE) contamination, including the Department of Energy's Savannah River Site (SRS) in Aiken, South Carolina. Previous studies have indicated that microorganisms are capable of efficiently degrading TCE to nonhazardous end products. In this project, molecular and growth based methods were used for microbial characterization of a TCE impacted seepzone where TCE degradation is naturally occurring. The results from this work provide clear evidence that the SRB may play a significant role in TCE degradation along the Twin Lakes seepline.
Date: March 7, 2005
Creator: ROBIN, BRIGMON
System: The UNT Digital Library
Computer-aided analysis of eddy current rotating probe data. (open access)

Computer-aided analysis of eddy current rotating probe data.

Eddy current (EC) estimate of flaw size obtained from inservice inspection is often the primary means of assessing the structural integrity of steam generator tubes. Reliable prediction of failure pressure and leak rate in tubes with complex cracking requires more detailed information about the geometry and extent of degradation than is generally available from conventional bobbin coil examinations. High-resolution inspections with EC rotating probes are thus carried out on selected regions of tubing to provide the more extensive nondestructive evaluation (NDE) information that is needed to better assess flaw size and distribution. Interpretation of signals from complex cracking that are often distorted by coherent and incoherent noise can be a challenging NDE task. Studies at Argonne National Laboratory have demonstrated that computer-aided data analysis can be used for more accurate and efficient processing of the large amounts of data collected by such probes. The basic structure of a rule-based multiparameter data analysis algorithm is described in this paper. Multiple-frequency inspection data from a standard rotating pancake coil were used for the analyses. The codes were implemented as MATLAB scripts and provide, as the final outcome, profiles of flaw depth in a section of tube. Graphical user interface tools were devised …
Date: March 7, 2002
Creator: Bakhtiari, S.; Park, J. Y.; Kupperman, D. S. & Shack, W. J.
System: The UNT Digital Library
Plutonium Disposition by Immobilization (open access)

Plutonium Disposition by Immobilization

The ultimate goal of the Department of Energy (DOE) Immobilization Project is to develop, construct, and operate facilities that will immobilize between 17 to 50 tonnes (MT) of U.S. surplus weapons-usable plutonium materials in waste forms that meet the ''spent fuel'' standard and are acceptable for disposal in a geologic repository. Using the ceramic can-in-canister technology selected for immobilization, surplus plutonium materials will be chemically combined into ceramic forms which will be encapsulated within large canisters of high level waste (HLW) glass. Deployment of the immobilization capability should occur by 2008 and be completed within 10 years. In support of this goal, the DOE Office of Fissile Materials Disposition (MD) is conducting development and testing (D&T) activities at four DOE laboratories under the technical leadership of Lawrence Livermore National Laboratory (LLNL). The Savannah River Site has been selected as the site for the planned Plutonium Immobilization Plant (PIP). The D&T effort, now in its third year, will establish the technical bases for the design, construction, and operation of the U. S. capability to immobilize surplus plutonium in a suitable and cost-effective manner. Based on the D&T effort and on the development of a conceptual design of the PIP, automation is …
Date: March 7, 2000
Creator: Gould, T.; DiSabatino, A. & Mitchell, M.
System: The UNT Digital Library
High Energy Gamma Rays from p+X, X=Cu, Ag, Au at 34 MeV (open access)

High Energy Gamma Rays from p+X, X=Cu, Ag, Au at 34 MeV

In this paper we present results from the measurement of the gamma ray yield in the reaction of 34-MeV protons on Cu, Ag and Au. The protons were produced by the University of Washington superconducting linac. The gamma rays were measured using a large NaI and two large BaF{sub 2} detectors. Angular distributions were obtained for each of the three targets. Data for the Cu and Ag target were taken at six lab angles between 35 and 135 degrees, while data were taken at eight lab angles between 35 and 135 degrees for the Au target. The data were compared to several models. These included Hauser-Feshbach and direct-semidirect (DSD) calculations. We also compared the measurements to proton-nucleus bremsstrahlung calculations. The bremsstrahlung calculations greatly underpredicted the cross section and produced an angular distribution which was too flat. The Hauser-Feshbach calculations reproduced the yield of the softer portion of the spectrum reasonably well for all three targets. The DSD calculations reproduced the yield and angular distributions quite well for energies above about 20 MeV. However, the yields were underpredicted in the 15-18 MeV region, which suggests that multistep mechanisms may be needed for this target.
Date: March 7, 2000
Creator: Luke, S. J.; Dietrich, F. S.; Chadwick, M. B.; Gossett, C. A.; Kaplan, M. S.; McLain, B. T. et al.
System: The UNT Digital Library
Impact of design options on natural circulation performance of the AFR-300 advanced fast reactor. (open access)

Impact of design options on natural circulation performance of the AFR-300 advanced fast reactor.

The AFR-300, Advanced Fast Reactor (300 Mwe), has been proposed as a Generation IV concept. It could also be used to dispose of surplus weapons grade plutonium or as an actinide burner for transmutation of high level radioactive waste. AFR-300 uses metallic fuel and sodium coolant. The design of AFR-300 takes account of the successful design and operation of EBR-II, but the AFR-300 design includes a number of advances such as an advanced fuel cycle, inspectability and improved economics. One significant difference between AFR-300 and EBR-II is that AFR-300 is considerably larger. Another significant difference is that AFR-300 has no auxiliary EM pump in the primary loop to guarantee positive core flow when the main primary pumps are shut down. Thus, one question that has come up in connection with the AFR-300 design is whether natural circulation flow is sufficient to prevent damage to the core if the primary pumps fail. Insufficient natural circulation flow through the core could result in high cladding temperatures and cladding failure due to eutectic penetration of the cladding by the metal fuel. The rate of eutectic penetration of the cladding is strongly temperature dependent, so cladding failure depends on how hot the cladding gets …
Date: March 7, 2002
Creator: Dunn, F. D.
System: The UNT Digital Library
An Optimal Ion Exchange Design for Removal of Cesium from Hanford Waste (open access)

An Optimal Ion Exchange Design for Removal of Cesium from Hanford Waste

Non-elutable crystalline silicotitanate (CST) ion-exchanger materials have been studied for removing cesium from a variety of radioactive wastes at several U.S. DOE sites over the last decade. For the current pretreatment facility design of the River Protection Project (RPP) Waste Treatment Plant (WTP) in Hanford, the removal of cesium from low activity waste (LAW) is achieved by ion-exchange technology based on SuperLig(R) 644 resin. However, due to concerns over potential radiological and chemical degradation of SuperLig(R) 644 resin, IONSIV IE-911 (CST in its engineered form) material is being proposed as a backup ion-exchange material for the removal of cesium from Hanford radioactive waste. This paper discusses the methodology used to determine the optimal CST ion-exchange column size to process all 16 separate batches of feeds from the ten targeted Hanford waste tanks. The optimal design ensures the best utilization of CST material and therefore results in a minimum amount of spent CST.
Date: March 7, 2002
Creator: Hang, T.
System: The UNT Digital Library
Divertor Target Heat Load Reduction by Electrical Biasing, and Application to COMPASS-D (open access)

Divertor Target Heat Load Reduction by Electrical Biasing, and Application to COMPASS-D

A toroidally-asymmetric potential structure in the scrape-off layer (SOL) plasma may be formed by toroidally distributed electrical biasing of the divertor target tiles. The resulting ExB convective motions should increase the plasma radial transport in the SOL and thereby reduce the heat load at the divertor [1]. In this paper we develop theoretical modeling and describe the implementation of this concept to the COMPASS-D divertor. We show that strong magnetic shear near the X-point should cause significant squeezing of the convective cells preventing convection from penetrating above the X-point. This should result in reduced heat load at the divertor target without increasing the radial transport in the portion of the SOL in direct contact with the core plasma, potentially avoiding any confinement degradation. implementation of divertor biasing is in hand on COMPASS-D involving insulation of, and modifications to, the present divertor tiles. Calculations based on measured edge parameters suggest that modest currents {approx} 8 A/tile are required, at up to 150V, to drive the convection. A technical test is preceeding full bias experiments.
Date: March 7, 2001
Creator: Fielding, S. J.; Cohen, R. H.; Helander, P. & Ryutov, D. D.
System: The UNT Digital Library
Nondestructive evaluation and assay for the plutonium ceramification test facility (open access)

Nondestructive evaluation and assay for the plutonium ceramification test facility

Lawrence Livermore National Laboratory (LLNL) has conducted design and testing activities of the Nondestructive Assay/Evaluation (NDA/NDE) system that will be installed to support the Plutonium Ceramification Test Facility (PuCTF). PuCTF immobilizes plutonium using the ceramic can-in-canister technology. The overall function of the NDA/NDE System is to ensure that sintered pucks contain the appropriate materials for ceramification process control, special nuclear materials (SNM) accountability, and repository acceptance. The system accepts sample pucks from the ceramification system, performs measurements, and determines if the product pucks are acceptable. This report details the conceptual system that is being developed.
Date: March 7, 2000
Creator: Mitchell, M.; Pugh, D. & Wang, T. F.
System: The UNT Digital Library
Delta/Alpha-Prime Phase Transformations in a Pu-Ga Alloy (open access)

Delta/Alpha-Prime Phase Transformations in a Pu-Ga Alloy

In pure plutonium, the monoclinic {alpha} phase is the equilibrium phase at ambient temperature and pressure. The addition of a few percent of gallium, however, allows the fcc {delta} phase to be retained metastablely at ambient conditions. When the metastable {delta} phase is cooled to subambient temperatures, it partially transforms to the monoclinic {alpha}' phase, which has gallium supersaturated in the lattice. The {alpha}' phase reverts to the {delta} phase when the sample is heated above the ambient temperature. The martensite burst (M{sub b}) and reversion start (R{sub s}) temperatures are functions of the composition, heating rate, and prior thermal history. For a Pu-2.0 at% Ga alloy, the transformation hysteresis is approximately 150 C, which is large compared with other solid-solid phase transformations. Both the forward and reverse transformations are martensitic and proceed via a burst mode. Here, we use differential scanning calorimetry (DSC) and resistometry to perform fundamental studies of the {alpha}'/{delta} transformations with the goal of understanding how aging may affect {delta} phase stability, particularly the M{sub b} temperature. Because materials properties of the {alpha}' and {delta} phases are considerably different (including a density increase of 25% and an accompanying resistivity increase of 46% upon transformation from {delta} …
Date: March 7, 2005
Creator: Blobaum, K M; Krenn, C R; Wall, M A & Schwartz, A J
System: The UNT Digital Library