Advanced Large Area Plastic Scintillator Project (ALPS): Final Report (open access)

Advanced Large Area Plastic Scintillator Project (ALPS): Final Report

The advanced Large-Area Plastic Scintillator (ALPS) Project at Pacific Northwest National Laboratory investigated possible technological avenues for substantially advancing the state-of-the-art in gamma-ray detection via large-area plastic scintillators. The three predominant themes of these investigations comprised the following: * Maximizing light collection efficiency from a single large-area sheet of plastic scintillator, and optimizing hardware event trigger definition to retain detection efficiency while exploiting the power of coincidence to suppress single-PMT "dark current" background; * Utilizing anti-Compton vetoing and supplementary spectral information from a co-located secondary, or "Back" detector, to both (1) minimize Compton background in the low-energy portion of the "Front" scintillator's pulse-height spectrum, and (2) sharpen the statistical accuracy of the front detector's low-energy response prediction as impelmented in suitable energy-windowing algorithms; and * Investigating alternative materials to enhance the intrinsic gamma-ray detection efficiency of plastic-based sensors.
Date: February 5, 2008
Creator: Jordan, David V.; Reeder, Paul L.; Todd, Lindsay C.; Warren, Glen A.; McCormick, Kathleen R.; Stephens, Daniel L. et al.
Object Type: Report
System: The UNT Digital Library
A 30 ps Timing Resolution for Single Photons with Multi-pixel Burle MCP-PMT (open access)

A 30 ps Timing Resolution for Single Photons with Multi-pixel Burle MCP-PMT

We have achieved {approx}30 psec single-photoelectron and {approx}12ps for multi-photoelectron timing resolution with a new 64 pixel Burle MCP-PMT with 10 micron microchannel holes. We have also demonstrated that this detector works in a magnetic field of 15kG, and achieved a single-photoelectron timing resolution of better than 60 psec. The study is relevant for a new focusing DIRC RICH detector for particle identification at future Colliders such as the super B-factory or ILC, and for future TOF techniques. This study shows that a highly pixilated MCP-PMT can deliver excellent timing resolution.
Date: July 5, 2006
Creator: Va'vra, J.; Benitez, J.; Coleman, J.; Leith, D. W. G. S.; Mazaheri, G.; Ratcliff, B. et al.
Object Type: Article
System: The UNT Digital Library
RECENT BEAM MEASUREMENTS AND NEW INSTRUMENTATION AT THE ADVANCED LIGHT SOURCE (open access)

RECENT BEAM MEASUREMENTS AND NEW INSTRUMENTATION AT THE ADVANCED LIGHT SOURCE

The Advanced Light Source (ALS) in Berkeley was the first of the soft x-ray third generation light source ever built, and since 1993 has been in continuous and successful operation serving a large community of users in the VUV and soft x-ray community. During these years the storage ring underwent through several important upgrades that allowed maintaining the performance of this veteran facility at the forefront. The ALS beam diagnostics and instrumentation have followed a similar path of innovation and upgrade and nowadays include most of the modem and last generation devices and technologies that are commercially available and used in the recently constructed third generation light sources. In this paper we will not focus on such already widely known systems, but we will concentrate our effort in the description of some measurements techniques, instrumentation and diagnostic systems specifically developed at the ALS and used during the last few years.
Date: May 5, 2008
Creator: Sannibale, Fernando; Baptiste, Kenneth; Barry, Walter; Chin, Michael; Filippetto, Daniele; Jaegerhofer, Lukas et al.
Object Type: Article
System: The UNT Digital Library
Magnetic Detachment and Plume Control in Escaping Magnetized Plasma (open access)

Magnetic Detachment and Plume Control in Escaping Magnetized Plasma

The model of two-fluid, axisymmetric, ambipolar magnetized plasma detachment from thruster guide fields is extended to include plasmas with non-zero injection angular velocity profiles. Certain plasma injection angular velocity profiles are shown to narrow the plasma plume, thereby increasing exhaust efficiency. As an example, we consider a magnetic guide field arising from a simple current ring and demonstrate plasma injection schemes that more than double the fraction of useful exhaust aperture area, more than halve the exhaust plume angle, and enhance magnetized plasma detachment.
Date: November 5, 2008
Creator: Fisch, P. F. Schmit and N. J.
Object Type: Report
System: The UNT Digital Library
TECHNICAL EQUIVALENCE BETWEEN PERKIN-ELMER DRCe AND ELAN 6000 FOR THE ANALYSIS OF 238U IN URINE BIOASSAY SAMPLES (open access)

TECHNICAL EQUIVALENCE BETWEEN PERKIN-ELMER DRCe AND ELAN 6000 FOR THE ANALYSIS OF 238U IN URINE BIOASSAY SAMPLES

The LLNL Bioassay Laboratory recently purchased a Perkin-Elmer DRCe ICP-MS (DRCe) to replace the existing Perkin-Elmer Elan 6000 ICP-MS (Elan 6000) used for the analysis of {sup 238}U in urine bioassay samples. In accordance with section 5.7.2 of DOE-STD-1112-98, 'The Department of Energy Laboratory Accreditation Program for Radiobioassay', this document demonstrates that the DRCe is technically equivalent to the Elan 6000. This paper documents: (1) Minor changes made in the procedure to improve the sensitivity; (2) Detection limits for the Elan 6000 and the DRCe; (3) Determination of the measurement uncertainty for the DRCe; and (4) Comparison of results from the DRCe versus the Elan 6000. A 1 mL aliquot of the sample is transferred to an auto sampler tube. Nitric acid and {sup 233}U (used as an internal standard) are added to the samples and the samples are digested in a microwave oven. The digested samples are diluted to 10 mL with deionized water and the {sup 238}U concentration is determined by ICP-MS. The ICP-MS is calibrated with a series of {sup 238}U standards. {sup 233}U is used as an internal standard to correct for suppression of the signal due to the sample matrix. The Elan 6000 is run …
Date: September 5, 2007
Creator: Wong, C T & Collins, L J
Object Type: Report
System: The UNT Digital Library
Imaging at high spatial resolution: Soft x-ray microscopy to 15nm (open access)

Imaging at high spatial resolution: Soft x-ray microscopy to 15nm

Soft x-ray microscopy has now achieved 15 nm spatial resolution with new zone plates and bending magnet radiation. Combined with elemental sensitivity and flexible sample environment (applied magnetic or electric fields, wet samples, windows, overcoatings) this emerges as a valuable tool for nanoscience and nanotechnology, complimenting common electron and scanning tip microscopies. In this presentation we describe recent advances in spatial resolution, expectations for the near future, and applications to magnetic materials, bio-tomography, etc.
Date: April 5, 2006
Creator: Attwood, D.; Chao, W.; Anderson, E.; Liddle, J. A.; Harteneck, B.; Fischer, P. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Color-Suppressed B0->D(*)0 pi0 /omega/eta/eta Prime Branching Fractions (open access)

Measurement of the Color-Suppressed B0->D(*)0 pi0 /omega/eta/eta Prime Branching Fractions

The authors report results on the branching fraction (BF) measurement of the color-suppressed decays {bar B}{sup 0} {yields} D{sup 0}{pi}{sup 0}, D*{sup 0}{pi}{sup 0}, D{sup 0}{eta}, D*{sup 0}{eta}, D{sup 0}{omega}, D*{sup 0}{omega}, D{sup 0}{eta}{prime}, and D*{sup 0}{eta}{prime}. They measure the branching fractions BF(D{sup 0}{pi}{sup 0}) = (2.78 {+-} 0.08 {+-} 0.20) x 10{sup -4}, BF(D*{sup 0}{pi}{sup 0}) = (1.78 {+-} 0.13 {+-} 0.23) x 10{sup -4}, BF(D{sup 0}{eta}) = (2.41 {+-} 0.09 {+-} 0.17) x 10{sup -4}, BF(D*{sup 0}{eta}) = (2.32 {+-} 0.13 {+-} 0.22) x 10{sup -4}, BF(D{sup 0}{omega}) = (2.77 {+-} 0.13 {+-} 0.22) x 10{sup -4}, BF(D*{sup 0}{omega}) = (4.44 {+-} 0.23 {+-} 0.61) x 10{sup -4}, BF(D{sup 0}{eta}{prime}) = (1.38 {+-} 0.12 {+-} 0.22) x 10{sup -4} and BF(D*{sup 0}{eta}{prime}) = (1.29 {+-} 0.23 {+-} 0.23) x 10{sup -4}, where the first uncertainty is statistical and the second is systematic. The result is based on a sample of (454 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the {Upsilon}(4S) resonance from 1999 to 2007, with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center. The measurements are compared to theoretical predictions by factorization, SCET and pQCD. The presence of …
Date: November 5, 2008
Creator: Prudent, X
Object Type: Article
System: The UNT Digital Library
Evaluation of radioactive background rejection in 76Ge neutrino-lessdouble-beta decay experiments using a highly segmented HPGe detector (open access)

Evaluation of radioactive background rejection in 76Ge neutrino-lessdouble-beta decay experiments using a highly segmented HPGe detector

A highly segmented coaxial HPGe detector was operated in a low background counting facility for over 1 year to experimentally evaluate possible segmentation strategies for the proposed Majorana neutrino-less double-beta decay experiment. Segmentation schemes were evaluated on their ability to reject multi-segment events while retaining single-segment events. To quantify a segmentation scheme's acceptance efficiency the percentage of peak area due to single segment events was calculated for peaks located in the energy region 911-2614 keV. Single interaction site events were represented by the double-escape peak from the 2614 keV decay in {sup 208}Tl located at 1592 keV. In spite of its prototypical nature, the detector performed well under realistic operating conditions and required only minimal human interaction. Though the energy resolution for events with interactions in multiple segments was impacted by inter-segment cross-talk, the implementation of a cross-talk correlation matrix restored acceptable resolution. Additionally, simulations utilizing the MaGe simulation package were performed and found to be in good agreement with experimental observations verifying the external nature of the background radiation.
Date: February 5, 2007
Creator: Chan, Yuen-Dat; Campbell, D. B.; Vetter, K.; Henning, R.; Lesko, K.; Chan, Y. D. et al.
Object Type: Article
System: The UNT Digital Library
Analysis of the Effects of Compositional and Configurational Assumptions on Product Costs for the Thermochemical Conversion of Lignocellulosic Biomass to Mixed Alcohols -- FY 2007 Progress Report (open access)

Analysis of the Effects of Compositional and Configurational Assumptions on Product Costs for the Thermochemical Conversion of Lignocellulosic Biomass to Mixed Alcohols -- FY 2007 Progress Report

The purpose of this study was to examine alternative biomass-to-ethanol conversion process assumptions and configuration options to determine their relative effects on overall process economics. A process-flow-sheet computer model was used to determine the heat and material balance for each configuration that was studied. The heat and material balance was then fed to a costing spreadsheet to determine the impact on the ethanol selling price. By examining a number of operational and configuration alternatives and comparing the results to the base flow sheet, alternatives having the greatest impact the performance and cost of the overall system were identified and used to make decisions on research priorities.
Date: December 5, 2008
Creator: Zhu, Yunhua; Gerber, Mark A.; Jones, Susanne B. & Stevens, Don J.
Object Type: Report
System: The UNT Digital Library
Development of an Optimum Tracer Set for Apportioning Emissions of Individual Power Plants Using Highly Time-Resolved Measurements and Advanced Receptor Modeling (open access)

Development of an Optimum Tracer Set for Apportioning Emissions of Individual Power Plants Using Highly Time-Resolved Measurements and Advanced Receptor Modeling

In previous studies, 11 elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) were determined in 30-minute aerosol samples collected with the University of Maryland Semicontinuous Elements in Aerosol Sampler (SEAS; Kidwell and Ondov, 2001, 2004; SEAS-II) in several locations in which air quality is influenced by emissions from coal- or oil-fired power plants. At this time resolution, plumes from stationary high temperature combustion sources are readily detected as large excursions in ambient concentrations of elements emitted by these sources (Pancras et al. ). Moreover, the time-series data contain intrinsic information on the lateral diffusion of the plume (e.g., {sigma}{sub y}), which Park et al. (2005 and 2006) have exploited in their Pseudo-Deterministic Receptor Model (PDRM), to calculate emission rates of SO{sub 2} and 11 elements (mentioned above) from four individual coal- and oil-fired power plants in the Tampa Bay area. In the current project, we proposed that the resolving power of source apportionment methods might be improved by expanding the set of maker species and that there exist some optimum set of marker species that could be used. The ultimate goal was to determine the utility of using additional elements to better identify and isolate …
Date: July 5, 2007
Creator: Ondov, John & Beachley, Gregory
Object Type: Report
System: The UNT Digital Library
Use of Optically Stimulated Luminescence Imaging Plates and Reader for Arms Control Applications (open access)

Use of Optically Stimulated Luminescence Imaging Plates and Reader for Arms Control Applications

Optically Stimulated Luminescence (OSL) technology has been pioneered at the Pacific Northwest National Laboratory (PNNL) for applications in personnel radiation dosimetry and commercially has become highly successful in replacing older technologies such as Thermoluminescence Dosimeters (TLDs) and film. OSL phosphors are used to measure radiation exposure by illuminating them with light after ionizing radiation exposure and measuring the amount of light emitted by the OSL phosphor. By using a two-dimensional plate of OSL material and raster scanning a light beam across the OSL plate a radiation pattern or image can be measured. The Arms Control community requires an electrons-free medium to measure the attributes of extent and symmetry on Pu pits in storage containers. OSL technology, used in the two-dimensional imaging mode, provides a means to measure these attributes with exposure times on the order of an hour. A special OSL reader has been built by PNNL to measure OSL imaging plates with a size of 20 cm by 30 cm. The reader uses 10 light emitting diode clusters with 10 corresponding photomultiplier tubes to measure an OSL imaging plate in less than 5 minutes. The resolution of each of the 10 measurement assemblies is 1 square-centimeter. A collimator assembly …
Date: July 5, 2001
Creator: Miller, Steven D.; Tomeraasen, Paul L.; Burghard, Brion J. & Traub, Richard J.
Object Type: Report
System: The UNT Digital Library
SAFETY IMPROVES DRAMATICALLY IN FLUOR HANFORD SOIL AND GROUNDWATER REMEDIATION PROJECT (open access)

SAFETY IMPROVES DRAMATICALLY IN FLUOR HANFORD SOIL AND GROUNDWATER REMEDIATION PROJECT

This paper describes dramatic improvements in the safety record of the Soil and Groundwater Remediation Project (SGRP) at the Hanford Site in southeast Washington state over the past four years. During a period of enormous growth in project work and scope, contractor Fluor Hanford reduced injuries, accidents, and other safety-related incidents and enhanced a safety culture that earned the SGRP Star Status in the Department of Energy's (DOE's) Voluntary Protection Program (VPP) in 2007. This paper outlines the complex and multi-faceted work of Fluor Hanford's SGRP and details the steps taken by the project's Field Operations and Safety organizations to improve safety. Holding field safety meetings and walkdowns, broadening safety inspections, organizing employee safety councils, intensively flowing down safety requirements to subcontractors, and adopting other methods to achieve remarkable improvement in safety are discussed. The roles of management, labor and subcontractors are detailed. Finally, SGRP's safety improvements are discussed within the context of overall safety enhancements made by Fluor Hanford in the company's 11 years of managing nuclear waste cleanup at the Hanford Site.
Date: December 5, 2007
Creator: Gerber, M. S.
Object Type: Article
System: The UNT Digital Library
Supersymmetry and Superstring Phenomenology (open access)

Supersymmetry and Superstring Phenomenology

We briefly cover the early history of supersymmetry, describe the relation of SUSY quantum field theories to superstring theories and explain why they are considered a likely tool to describe the phenomenology of high energy particle theory beyond the Standard Model.
Date: May 5, 2008
Creator: Gaillard, Mary K; Gaillard, Mary K. & Zumino, Bruno
Object Type: Article
System: The UNT Digital Library
Far-from-equilibrium measurements of thermodynamic length (open access)

Far-from-equilibrium measurements of thermodynamic length

Thermodynamic length is a path function that generalizes the notion of length to the surface of thermodynamic states. Here, we show how to measure thermodynamic length in far-from-equilibrium experiments using the work fluctuation relations. For these microscopic systems, it proves necessary to define the thermodynamic length in terms of the Fisher information. Consequently, the thermodynamic length can be directly related to the magnitude of fluctuations about equilibrium. The work fluctuation relations link the work and the free energy change during an external perturbation on a system. We use this result to determine equilibrium averages at intermediate points of the protocol in which the system is out-of-equilibrium. This allows us to extend Bennett's method to determine the potential of mean force, as well as the thermodynamic length, in single molecule experiments.
Date: November 5, 2008
Creator: Feng, Edward H. & Crooks, Gavin E.
Object Type: Article
System: The UNT Digital Library
Rbrc Scientific Review Committee Meeting - Volume 87 (open access)

Rbrc Scientific Review Committee Meeting - Volume 87

None
Date: November 5, 2007
Creator: Samios, N. P.
Object Type: Article
System: The UNT Digital Library
Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 6. Summary (open access)

Historical Doses from Tritiated Water and Tritiated Hydrogen Gas Released to the Atmosphere from Lawrence Livermore National Laboratory (LLNL). Part 6. Summary

Throughout fifty-three years of operations, an estimated 792,000 Ci (29,300 TBq) of tritium have been released to the atmosphere at the Livermore site of Lawrence Livermore National Laboratory (LLNL); about 75% was tritium gas (HT) primarily from the accidental releases of 1965 and 1970. Routine emissions contributed slightly more than 100,000 Ci (3,700 TBq) HT and about 75,000 Ci (2,800 TBq) tritiated water vapor (HTO) to the total. A Tritium Dose Reconstruction was undertaken to estimate both the annual doses to the public for each year of LLNL operations and the doses from the few accidental releases. Some of the dose calculations were new, and the others could be compared with those calculated by LLNL. Annual doses (means and 95% confidence intervals) to the potentially most exposed member of the public were calculated for all years using the same model and the same assumptions. Predicted tritium concentrations in air were compared with observed mean annual concentrations at one location from 1973 onwards. Doses predicted from annual emissions were compared with those reported in the past by LLNL. The highest annual mean dose predicted from routine emissions was 34 {micro}Sv (3.4 mrem) in 1957; its upper confidence limit, based on very …
Date: September 5, 2007
Creator: Peterson, S
Object Type: Report
System: The UNT Digital Library
Spatial scaling metrics of mask-induced induced line-edge roughness (open access)

Spatial scaling metrics of mask-induced induced line-edge roughness

Mask contributors to line-edge roughness (LER) have recently been shown to be an issue of concern for both the accuracy of current resist evaluation tests as well the ultimate LER requirements for the 22-nm production node. Problems arise from mask absorber LER as well as mask reflector or surface roughness leading to random phase variations in the reflected beam. Not only do these mask contributors effect to total measured LER in resist, but they also effect LER spatial characteristic such as the LER power spectral density and related descriptors of correlation length and roughness exponent. Noting that these characteristics are important in the understanding of LER, it is crucial to understand how mask effects impact these parameters. Moreover, understanding how these metrics respond to mask effects may lead to an experimental mechanism for experimentally evaluating the importance of mask contributors to LER. Here we use computer modeling to study the LER spatial metrics arising from mask effects. We further describe the effects of illumination conditions and defocus on the metrics and compare the results to those expected from intrinsic resist LER.
Date: September 5, 2008
Creator: Naulleau, Patrick P. & Gallatin, Gregg
Object Type: Article
System: The UNT Digital Library
Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments. (open access)

Crack growth rates and metallographic examinations of Alloy 600 and Alloy 82/182 from field components and laboratory materials tested in PWR environments.

In light water reactors, components made of nickel-base alloys are susceptible to environmentally assisted cracking. This report summarizes the crack growth rate results and related metallography for field and laboratory-procured Alloy 600 and its weld alloys tested in pressurized water reactor (PWR) environments. The report also presents crack growth rate (CGR) results for a shielded-metal-arc weld of Alloy 182 in a simulated PWR environment as a function of temperature between 290 C and 350 C. These data were used to determine the activation energy for crack growth in Alloy 182 welds. The tests were performed by measuring the changes in the stress corrosion CGR as the temperatures were varied during the test. The difference in electrochemical potential between the specimen and the Ni/NiO line was maintained constant at each temperature by adjusting the hydrogen overpressure on the water supply tank. The CGR data as a function of temperature yielded activation energies of 252 kJ/mol for a double-J weld and 189 kJ/mol for a deep-groove weld. These values are in good agreement with the data reported in the literature. The data reported here and those in the literature suggest that the average activation energy for Alloy 182 welds is on the …
Date: May 5, 2008
Creator: Alexandreanu, B.; Chopra, O. K. & Shack, W. J.
Object Type: Report
System: The UNT Digital Library
Anthropogenically-Induced Climate Change: Final Report (open access)

Anthropogenically-Induced Climate Change: Final Report

Paper number 1 addresses the fact that the procedure used in the Earth Radiation Budget Experiment for identifying the presence of clouds over snow/ice surfaces is known to have shortcomings, and this is corroborated through use of surface insolation measurements at the South Pole as an independent means of identifying clouds. These surface insolation measurements are then used to validate the more detailed cloud identification scheme used in the follow-up Clouds and the Earth's Radiant Energy System (CERES), and this validation is extended to the polar night through use of CERES measurements of the outgoing longwave radiation. General circulation models (GCMs) are highly sophisticated computer tools for modeling climate change, and they incorporate a large number of physical processes and variables. One of the most important challenges is to properly account for water vapor (clouds and humidity) in climate warming. In this Perspective, Cess discusses results reported in the same issue by Soden et al. in which water vapor feedback effects are tested by studying moistening trends in the upper troposphere. Satellite observations of atmospheric water vapor are found to agree well with moisture predictions generated by one of the key GCMs, showing that these feedback effects are being properly …
Date: December 5, 2008
Creator: Cess, Robert D.
Object Type: Report
System: The UNT Digital Library
The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites (open access)

The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 348 {+-} 19 Ma and an {var_epsilon}{sub Nd}{sup 143} value of +40.1 {+-} 1.3. Maskelynite fractions do not lie on the Sm-Nd isochron and appear to contain a martian surface component with low {sup 147}Sm/{sup 144}Nd and {sup 143}Nd/{sup 144}Nd ratios that was added during shock. The Rb-Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial {sup 87}Sr/{sup 86}Sr ratio of 0.701614 {+-} 16 is estimated by passing a 348 Ma reference isochron through the maskelynite fraction that is least affected by contamination. The high initial {var_epsilon}{sub Nd}{sup 143} value and the low initial {sup 87}Sr/{sup 86}Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with nearly identical Sr-Nd isotopic systematics. These …
Date: April 5, 2007
Creator: Symes, S; Borg, L; Shearer, C & Irving, A
Object Type: Article
System: The UNT Digital Library
What Is the Largest Einstein Radius in the Universe? (open access)

What Is the Largest Einstein Radius in the Universe?

The Einstein radius plays a central role in lens studies as it characterizes the strength of gravitational lensing. In particular, the distribution of Einstein radii near the upper cutoff should probe the probability distribution of the largest mass concentrations in the universe. Adopting a triaxial halo model, we compute expected distributions of large Einstein radii. To assess the cosmic variance, we generate a number of Monte-Carlo realizations of all-sky catalogues of massive clusters. We find that the expected largest Einstein radius in the universe is sensitive to parameters characterizing the cosmological model, especially {sigma}{sub s}: for a source redshift of unity, they are 42{sub -7}{sup +9}, 35{sub -6}{sup +8}, and 54{sub -7}{sup +12} arcseconds (errors denote 1{sigma} cosmic variance), assuming best-fit cosmological parameters of the Wilkinson Microwave Anisotropy Probe five-year (WMAP5), three-year (WMAP3) and one-year (WMAP1) data, respectively. These values are broadly consistent with current observations given their incompleteness. The mass of the largest lens cluster can be as small as {approx} 10{sup 15} M{sub {circle_dot}}. For the same source redshift, we expect in all-sky {approx} 35 (WMAP5), {approx} 15 (WMAP3), and {approx} 150 (WMAP1) clusters that have Einstein radii larger than 2000. For a larger source redshift of 7, …
Date: August 5, 2008
Creator: Oguri, Masamune & Blandford, Roger D.
Object Type: Article
System: The UNT Digital Library
Configuration and Technology Implications of Potential Nuclear Hydrogen System Applications. (open access)

Configuration and Technology Implications of Potential Nuclear Hydrogen System Applications.

Nuclear technologies have important distinctions and potential advantages for large-scale generation of hydrogen for U.S. energy services. Nuclear hydrogen requires no imported fossil fuels, results in lower greenhouse-gas emissions and other pollutants, lends itself to large-scale production, and is sustainable. The technical uncertainties in nuclear hydrogen processes and the reactor technologies needed to enable these processes, as well waste, proliferation, and economic issues must be successfully addressed before nuclear energy can be a major contributor to the nation's energy future. In order to address technical issues in the time frame needed to provide optimized hydrogen production choices, the Nuclear Hydrogen Initiative (NHI) must examine a wide range of new technologies, make the best use of research funding, and make early decisions on which technology options to pursue. For these reasons, it is important that system integration studies be performed to help guide the decisions made in the NHI. In framing the scope of system integration analyses, there is a hierarchy of questions that should be addressed: What hydrogen markets will exist and what are their characteristics? Which markets are most consistent with nuclear hydrogen? What nuclear power and production process configurations are optimal? What requirements are placed on the nuclear …
Date: November 5, 2005
Creator: Conzelmann, G.; Petri, M.; Forsberg, C. & Yildiz, B.
Object Type: Report
System: The UNT Digital Library
High Temperature Superconducting Reciprocating Magnetic Separator Final Report (open access)

High Temperature Superconducting Reciprocating Magnetic Separator Final Report

In 2001, under DOE's Superconductivity Partnership Initiative (SPI), E. I. du Pont de Nemours & Co. (Dupont) was awarded a cost-share contract to build a fully functional full-scale model high temperature superconducting reciprocating magnet unit specifically designed for the koalin clay industry. After competitive bidding, American Superconductor (AMSC) was selected to provide the coil for the magnet. Dupont performed the statement of work until September 2004, when it stopped work, with the concurrence of DOE, due to lack of federal funds. DOE had paid all invoices to that point, and Dupont had provided all cost share. At this same time, Dupont determined that this program did not fit with its corporate strategies and notified DOE that it was not interesting in resuming the program when funding became available. AMSC expressed interest in assuming performance of the Agreement to Dupont and DOE, and in March 2005, this project was transferred to AMSC by DOE amendment to the original contract and Novation Agreement between AMSC and Dupont. Design drawings and some hardware components and subassemblies were transferred to AMSC. However, no funding was obligated by DOE and AMSC never performed work on the project. This report contains a summary of the work …
Date: June 5, 2008
Creator: Maguire, James F.
Object Type: Report
System: The UNT Digital Library
Observations of Plasmons in Warm Dense Matter (open access)

Observations of Plasmons in Warm Dense Matter

We present the first collective x-ray scattering measurements of plasmons in solid-density plasmas. The forward scattering spectra of a laser-produced narrow-band x-ray line from isochorically heated beryllium show that the plasmon frequency is a sensitive measure of the electron density. Dynamic structure calculations that include collisions and detailed balance match the measured plasmon spectrum indicating that this technique will enable new applications to determine the equation of state and compressibility of dense matter.
Date: September 5, 2006
Creator: Glenzer, S H; Landen, O L; Neumayer, P; Lee, R W; Widmann, K; Pollaine, S W et al.
Object Type: Article
System: The UNT Digital Library