States

Ab Initio Many-Body Calculations Of n-3H, n-4He, p-3,4He, And n-10Be Scattering (open access)

Ab Initio Many-Body Calculations Of n-3H, n-4He, p-3,4He, And n-10Be Scattering

We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We present phase shifts for neutron scattering on {sup 3}H, {sup 4}He and {sup 10}Be and proton scattering on {sup 3,4}He, using realistic nucleon-nucleon potentials. Our A = 4 scattering results are compared to earlier ab initio calculations. We demonstrate that a proper treatment of the coupling to the n-{sup 10}Be continuum is essential to explain the parity-inverted ground state in {sup 11}Be.
Date: March 26, 2008
Creator: Quaglioni, S & Navratil, P
Object Type: Article
System: The UNT Digital Library
Beam Loss Studies for Rare Isotope Driver Linacs Final Report (open access)

Beam Loss Studies for Rare Isotope Driver Linacs Final Report

The Fortran 90 RIAPMTQ/IMPACT code package is a pair of linked beam-dynamics simulation codes that have been developed for end-to-end computer simulations of multiple-charge-state heavy-ion linacs for future exotic-beam facilities. These codes have multiple charge-state capability, and include space-charge forces. The simulations can extend from the low-energy beam-transport line after an ECR ion source to the end of the linac. The work has been performed by a collaboration including LANL, LBNL, ANL, and MSU. The code RIAPMTQ simulates the linac front-end beam dynamics including the LEBT, RFQ, and MEBT. The code IMPACT simulates the beam dynamics of the main superconducting linac. The codes have been benchmarked for rms beam properties against previously existing codes at ANL and MSU. The codes allow high-statistics runs on parallel supercomputing platforms, particularly at NERSC at LBNL, for studies of beam losses. The codes also run on desktop PC computers for low-statistics work. The code package is described in more detail in a recent publication [1] in the Proceedings of PAC07 (2007 US Particle Accelerator Conference). In this report we describe the main activities for the FY07 beam-loss studies project using this code package.
Date: March 26, 2008
Creator: Wangler, T. P.; Kurennoy, S. S.; Billen, J. H.; Crandall, K. R.; Qiang, J.; Ryne, R. D. et al.
Object Type: Report
System: The UNT Digital Library
Calibration of the HB line active well neutron coincidence counter for measurement of LANL 3013 highly enriched uranium product splits (open access)

Calibration of the HB line active well neutron coincidence counter for measurement of LANL 3013 highly enriched uranium product splits

None
Date: March 26, 2008
Creator: Dewberry, R.; Williams, D. R.; Lee, R. S.; Roberts, D. W.; Arrigo, L. M. & Salaymeh, S. R.
Object Type: Article
System: The UNT Digital Library
Determination of the Evaporation Coefficient of D2O (open access)

Determination of the Evaporation Coefficient of D2O

The evaporation rate of D{sub 2}O has been determined by Raman thermometry of a droplet train (12-15 {micro}m diameter) injected into vacuum ({approx}10{sup -5} torr). The cooling rate measured as a function of time in vacuum was fit to a model that accounts for temperature gradients between the surface and the core of the droplets, yielding an evaporation coefficient ({gamma}{sub e}) of 0.57 {+-} 0.06. This is nearly identical to that found for H{sub 2}O (0.62 {+-} 0.09) using the same experimental method and model, and indicates the existence of a kinetic barrier to evaporation. The application of a recently developed transition state theory (TST) model suggests that the kinetic barrier is due to librational and hindered translational motions at the liquid surface, and that the lack of an isotope effect is due to competing energetic and entropic factors. The implications of these results for cloud and aerosol particles in the atmosphere are discussed.
Date: March 26, 2008
Creator: Drisdell, Walter S.; Cappa, Christopher D.; Smith, Jared D.; Saykally, Richard J. & Cohen, Ronald C.
Object Type: Article
System: The UNT Digital Library
Feasibility Study for Photovoltaics, Wind, solar Hot Water and Hybrid Systems (open access)

Feasibility Study for Photovoltaics, Wind, solar Hot Water and Hybrid Systems

Southwestern Indian Polytechnic Institute (SIPI) located in Albuquerque New Mexico is a community college that serves American Indians and Alaska Natives. SIPI’s student body represents over 100 Native American Tribes. SIPI completed a renewable energy feasibility study program and established renewable energy hardware on the SIPI campus, which supplements and creates an educational resource to teach renewable energy courses. The SIPI campus is located, and has as student origins, areas, in which power is an issue in remote reservations. The following hardware was installed and integrated into the campus facilities: small wind turbine, large photovoltaic array that is grid-connected, two photovoltaic arrays, one thin film type, and one polycrystalline type, one dual-axis active tracker and one passive tracker, a hot air system for heating a small building, a portable hybrid photovoltaic system for remote power, and a hot water system to preheat water used in the SIPI Child Care facility. Educational curriculum has been developed for two renewable energy courses one being the study of energy production and use, and especially the roles renewable energy forms like solar, wind, geothermal, hydro, and biomass plays, and the second course being a more advanced in-depth study of renewable energy system design, maintenance, …
Date: March 26, 2008
Creator: Hooks, Ronald & Montoya, Valerie
Object Type: Report
System: The UNT Digital Library
Iron-Based Amorphous Coatings Produced by HVOF Thermal Spray Processing-Coating Structure and Properties (open access)

Iron-Based Amorphous Coatings Produced by HVOF Thermal Spray Processing-Coating Structure and Properties

The feasibility to coat large SNF/HLW containers with a structurally amorphous material (SAM) was demonstrated on sub-scale models fabricated from Type 316L stainless steel. The sub-scale model were coated with SAM 1651 material using kerosene high velocity oxygen fuel (HVOF) torch to thicknesses ranging from 1 mm to 2 mm. The process parameters such as standoff distance, oxygen flow, and kerosene flow, were optimized in order to improve the corrosion properties of the coatings. Testing in an electrochemical cell and long-term exposure to a salt spray environment were used to guide the selection of process parameters.
Date: March 26, 2008
Creator: Beardsley, M B
Object Type: Article
System: The UNT Digital Library
The Mercury Laser System-A scaleable average-power laser for fusion and beyond (open access)

The Mercury Laser System-A scaleable average-power laser for fusion and beyond

Nestled in a valley between the whitecaps of the Pacific and the snowcapped crests of the Sierra Nevada, Lawrence Livermore National Laboratory (LLNL) is home to the nearly complete National Ignition Facility (NIF). The purpose of NIF is to create a miniature star-on demand. An enormous amount of laser light energy (1.8 MJ in a pulse that is 20 ns in duration) will be focused into a small gold cylinder approximately the size of a pencil eraser. Centered in the gold cylinder (or hohlraum) will be a nearly perfect sphere filled with a complex mixture of hydrogen gas isotopes that is similar to the atmosphere of our Sun. During experiments, the laser light will hit the inside of the gold cylinder, heating the metal until it emits X-rays (similar to how your electric stove coil emits visible red light when heated). The X-rays will be used to compress the hydrogen-like gas with such pressure that the gas atoms will combine or 'fuse' together, producing the next heavier element (helium) and releasing energy in the form of energetic particles. 2010 will mark the first credible attempt at this world-changing event: the achievement of fusion energy 'break-even' on Earth using NIF, the …
Date: March 26, 2008
Creator: Ebbers, C A & Moses, E I
Object Type: Article
System: The UNT Digital Library
October 2007 Monitoring Results for Morrill, Kansas. (open access)

October 2007 Monitoring Results for Morrill, Kansas.

In September 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) initiated periodic sampling of groundwater in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Morrill, Kansas. On the basis of available information, the CCC/USDA believes that one or more third parties operated this facility after termination of the CCC/USDA's lease in 1971. The sampling at Morrill is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE), to monitor levels of carbon tetrachloride contamination identified in the groundwater at this site (Argonne 2004, 2005a). Under the KDHE-approved monitoring plan (Argonne 2005b), the groundwater has been sampled twice yearly for a recommended period of two years. The samples are analyzed for volatile organic compounds (VOCs), as well as for selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. The sampling is presently conducted in a network of 12 monitoring wells and 3 private wells (Figure 1.1), at locations approved by the KDHE. The scope of the originally approved monitoring has been expanded to include …
Date: March 26, 2008
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Report on Lessons Learned from the NP 2010 Early Site Permit Program FINAL REPORT (open access)

Report on Lessons Learned from the NP 2010 Early Site Permit Program FINAL REPORT

This report provides a summary of lessons learned from the demonstration of the licensing process for three Early Site Permit (ESP) applications supported as part of the Department of Energy’s (DOE) Nuclear Power 2010 (NP 2010) program. The ESP process was established by the Nuclear Regulatory Commission (NRC) to enable completion of the site evaluation component of nuclear power plant licensing under 10 CFR Part 52 before a utility makes a decision to build a plant. Early Site Permits are valid for 10 to 20 years and can be renewed for an additional 10 to 20 years. NRC review of an ESP application addresses site safety issues, environmental protection issues, and plans for coping with emergencies. Successful completion of the ESP process will establish that a site is suitable for possible future construction and operation of a nuclear power plant. Most importantly, an ESP resolves significant site-related safety and environmental issues early in the decision process and helps achieve acceptance by the public. DOE competitively selected Dominion Nuclear Energy North Anna, LLC (Dominion); System Energy Resources, Inc. (an Entergy subsidiary); and Exelon Generation Company, LLC (Exelon) in 2002 to demonstrate the ESP process and provided cost-shared support through the NP …
Date: March 26, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Studies of Correlated-Electron Systems in High Magnetic Fields and at High Pressures (open access)

Studies of Correlated-Electron Systems in High Magnetic Fields and at High Pressures

None
Date: March 26, 2008
Creator: Cornelius, Dr. Andrew
Object Type: Report
System: The UNT Digital Library
Wear Resistant Amorphous and Nanocomposite Coatings (open access)

Wear Resistant Amorphous and Nanocomposite Coatings

Glass forming materials (critical cooling rate <10{sup 4}K.s{sup -1}) are promising for their high corrosion and wear resistance. During rapid cooling, the materials form an amorphous structure that transforms to nanocrystalline during a process of devitrification. High hardness (HV 1690) can be achieved through a controlled crystallization. Thermal spray process has been used to apply coatings, which preserves the amorphous/nanocomposite structure due to a high cooling rate of the feedstock particles during the impact on a substrate. Wear properties have been studied with respect to process conditions and feedstock material properties. Application specific properties such as sliding wear resistance have been correlated with laboratory tests based on instrumented indentation and scratch tests.
Date: March 26, 2008
Creator: Racek, O.
Object Type: Article
System: The UNT Digital Library