Measurements of B to V(Gamma) Decays (open access)

Measurements of B to V(Gamma) Decays

The standard model has been highly successful at describing current experimental data. However, extensions of the standard model predict particles that have masses at energy scales that are above the electroweak scale. The flavor-changing neutral current processes of the B meson are sensitive to the influences of these new physics contributions. These processes proceed through loop diagrams, thus allowing new physics to enter at the same order as the standard model. New physics may contribute to the enhancement or suppression of rate asymmetries or the decay rates of these processes. The transition B {yields} V{gamma} (V = K*(892), {rho}(770), {omega}(782), {phi}(1020)) represents radiative decays of the B meson that proceed through penguin processes. Hadronic uncertainties limit the theoretical accuracy of the prediction of the branching fractions. However, uncertainties, both theoretical and experimental, are much reduced when considering quantities involving ratios of branching fractions, such as CP or isospin asymmetries. The most dominant exclusive radiative b {yields} s transition is B {yields} K*{gamma}. We present the best measurements of the branching fractions, direct CP, and isospin asymmetries of B {yields} K*{gamma}. The analogous b {yields} d transitions are B {yields} {rho}{gamma} and B {yields} {omega}{gamma}, which are suppressed by a factor …
Date: September 2, 2010
Creator: Yarritu, Aaron K.
Object Type: Report
System: The UNT Digital Library
Overhead Detection of Underground Nuclear Explosions by Multi-Spectral and Infrared Imaging (open access)

Overhead Detection of Underground Nuclear Explosions by Multi-Spectral and Infrared Imaging

None
Date: September 10, 2010
Creator: Henderson, J. R.; Smith, M. O. & Zelinski, M. E.
Object Type: Report
System: The UNT Digital Library
Aircraft Field Exercise to Develop Multi-Spectral and Infrared Imaging for CTBT On-Site Inspections (open access)

Aircraft Field Exercise to Develop Multi-Spectral and Infrared Imaging for CTBT On-Site Inspections

None
Date: September 10, 2010
Creator: Henderson, J. R.; Smith, M. O. & Zelinski, M. E.
Object Type: Report
System: The UNT Digital Library
Mesoporous Silica-Supported Metal Oxide-Promoted Rh Nanocatalyst for Selective Production of Ethanol from Syngas (open access)

Mesoporous Silica-Supported Metal Oxide-Promoted Rh Nanocatalyst for Selective Production of Ethanol from Syngas

The objective is to develop a process that will convert synthesis gas from coal into ethanol and then transform the ethanol into hydrogen. Principal investigators from Iowa State University include Dr. George Kraus, Dr. Victor Lin, Marek Pruski, and Dr. Robert Brown. Task 1 involves catalyst development and catalyst scale up. Mesoporous manganese silicate mixed oxide materials will be synthesized, characterized and evaluated. The first-and secondgeneration catalysts have been prepared and scaled up for use in Task 2. The construction of a high-pressure reactor system for producing synthetic liquid fuel from simulated synthesis gas stream has been completed as the first step in Task 2. Using the first- and second generation catalysts, the reactor has demonstrated the production of synthetic liquid fuel from a simulated synthesis gas stream.
Date: September 30, 2010
Creator: Kraus, George
Object Type: Report
System: The UNT Digital Library
Radon monitoring and early low background counting at the Sanford Underground Laboratory (open access)

Radon monitoring and early low background counting at the Sanford Underground Laboratory

Radon detectors have been deployed underground at the Sanford Underground Laboratory at the site of the former Homestake Mine in Lead, SD. Currently, no radon mitigation measures are in place in the underground environment, and the continuing evolution of the facility ventilation systems has led to significant variations in early airborne radon concentrations. The average radon concentration measured near the primary ventilation intake for the 4850-ft level (Yates shaft) is 391 Bq/m{sup 3}, based on approximately 146 days of data. The corresponding average radon concentration near the other main ventilation intake for the 4850-ft level (Ross shaft) is 440 Bq/m{sup 3} based on approximately 350 days of data. Measurements have also been collected near the 1250-ft level Ross shaft, with average radon concentrations at 180 Bq/m{sup 3}. Secondary factors that may increase the baseline radon level underground include the presence of iron oxide and moisture, which are known to enhance radon emanation. The results of the current radon monitoring program will be used for the planning of future measurements and any potential optimization of ventilation parameters for the reduction of radon in relevant areas underground.
Date: September 1, 2010
Creator: Thomas, K. J.; Mei, D. M.; Heise, J.; Durben, D. & Salve, R.
Object Type: Article
System: The UNT Digital Library
KEY DESIGN REQUIREMENTS FOR THE HIGH TEMPERATURE GAS-COOLED REACTOR NUCLEAR HEAT SUPPLY SYSTEM (open access)

KEY DESIGN REQUIREMENTS FOR THE HIGH TEMPERATURE GAS-COOLED REACTOR NUCLEAR HEAT SUPPLY SYSTEM

Key requirements that affect the design of the high temperature gas-cooled reactor nuclear heat supply system (HTGR-NHSS) as the NGNP Project progresses through the design, licensing, construction and testing of the first of a kind HTGR based plant are summarized. These requirements derive from pre-conceptual design development completed to-date by HTGR Suppliers, collaboration with potential end users of the HTGR technology to identify energy needs, evaluation of integration of the HTGR technology with industrial processes and recommendations of the NGNP Project Senior Advisory Group.
Date: September 1, 2010
Creator: Demick, L. E.
Object Type: Report
System: The UNT Digital Library
LANL Virtual Center for Chemical Hydrogen Storage: Chemical Hydrogen Storage Using Ultra-high Surface Area Main Group Materials (open access)

LANL Virtual Center for Chemical Hydrogen Storage: Chemical Hydrogen Storage Using Ultra-high Surface Area Main Group Materials

The focus of the project was to design and synthesize light element compounds and nanomaterials that will reversibly store molecular hydrogen for hydrogen storage materials. The primary targets investigated during the last year were amine and hydrogen terminated silicon (Si) nanoparticles, Si alloyed with lighter elements (carbon (C) and boron (B)) and boron nanoparticles. The large surface area of nanoparticles should facilitate a favorable weight to volume ratio, while the low molecular weight elements such as B, nitrogen (N), and Si exist in a variety of inexpensive and readily available precursors. Furthermore, small NPs of Si are nontoxic and non-corrosive. Insights gained from these studies will be applied toward the design and synthesis of hydrogen storage materials that meet the DOE 2010 hydrogen storage targets: cost, hydrogen capacity and reversibility. Two primary routes were explored for the production of nanoparticles smaller than 10 nm in diameter. The first was the reduction of the elemental halides to achieve nanomaterials with chloride surface termination that could subsequently be replaced with amine or hydrogen. The second was the reaction of alkali metal Si or Si alloys with ammonium halides to produce hydrogen capped nanomaterials. These materials were characterized via X-ray powder diffraction, TEM, …
Date: September 5, 2010
Creator: Kauzlarich, Susan M.; Power, Phillip P.; Neiner, Doinita; Pickering, Alex; Rivard, Eric; Bobby Ellis, T. M. et al.
Object Type: Report
System: The UNT Digital Library
Effect of atmosphere on collinear double-pulse laser-induced breakdown spectroscopy (open access)

Effect of atmosphere on collinear double-pulse laser-induced breakdown spectroscopy

Double pulse laser induced breakdown spectroscopy (DP-LIBS) has been shown to enhance LIBS spectra. Several researches have reported significant increases in signal-to-noise and or spectral intensity [1-4]. In addition to DP-LIBS, atmospheric conditions can also increase spectra intensity. For example, Iida [5] found that He and Ar both increase LIBS intensity compared to air at one 1 atm. It was also found that as the pressure was decreased to 100 Torr, LIBS intensity increased in Ar and air for single pulse (SP) LIBS. In this study, a collinear DP-LIBS scheme is used along with manipulation of the atmospheric conditions. The DP-LIBS scheme consists of a 355 nm ablative pulse fired into a sample contained in a vacuum chamber. A second analytical 1064 nm pulse is then fired 100 ns to 10 µs after and along the same path of the first pulse. Ar, He and air at pressures ranging from atmospheric pressure (630 Torr at elevation) to 10-5 Torr are introduced during DP-LIBS and SP-LIBS experiments. For a brass sample, a significant increase in spectral intensity of Cu and Zn lines were observed in DP-LIBS under Ar compared to DP-LIBS in air (Figure 1). It was also found that Cu …
Date: September 1, 2010
Creator: Effenberger, Andrew J., Jr. & Scott, Jill R.
Object Type: Article
System: The UNT Digital Library
Spin Crossover in Ferropericlase at High Pressure: A Seismically Hidden Transition? (open access)

Spin Crossover in Ferropericlase at High Pressure: A Seismically Hidden Transition?

None
Date: September 13, 2010
Creator: Antonangeli, Daniele; Siebert, Julien; Aracne, Chantel M.; Farber, Daniel L.; Bosak, A.; Hoesch, M. et al.
Object Type: Article
System: The UNT Digital Library
CAVITY CONTROL ALGORITHM (open access)

CAVITY CONTROL ALGORITHM

A digital low level radio frequency (RF) system typically incorporates either a heterodyne or direct sampling technique, followed by fast ADCs, then an FPGA, and finally a transmitting DAC. This universal platform opens up the possibilities for a variety of control algorithm implementations. The foremost concern for an RF control system is cavity field stability, and to meet the required quality of regulation, the chosen control system needs to have sufficient feedback gain. In this paper we will investigate the effectiveness of the regulation for three basic control system algorithms: I&Q (In-phase and Quadrature), Amplitude & Phase and digital SEL (Self Exciting Loop) along with the example of the Jefferson Lab 12 GeV cavity field control system.
Date: September 1, 2010
Creator: Plawski, Tomasz & Hovater, Curt
Object Type: Article
System: The UNT Digital Library
Investigating Chemical and Molecular Changes in Uranium Oxyfluoride Particles using NanoSIMS and Micro-Raman Spectroscopy (open access)

Investigating Chemical and Molecular Changes in Uranium Oxyfluoride Particles using NanoSIMS and Micro-Raman Spectroscopy

None
Date: September 14, 2010
Creator: Kips, R.; Kristo, M. J.; Crowhurst, J.; Hutcheon, I. D.; Stefaniak, E. A. & Aregbe, Y.
Object Type: Article
System: The UNT Digital Library