A COMPARISON OF GADRAS SIMULATED AND MEASURED GAMMA RAY SPECTRA (open access)

A COMPARISON OF GADRAS SIMULATED AND MEASURED GAMMA RAY SPECTRA

Gamma-ray radiation detection systems are continuously being developed and improved for detecting the presence of radioactive material and for identifying isotopes present. Gamma-ray spectra, from many different isotopes and in different types and thicknesses of attenuation material and matrixes, are needed to evaluate the performance of these devices. Recently, a test and evaluation exercise was performed by the Savannah River National Laboratory that required a large number of gamma-ray spectra. Simulated spectra were used for a major portion of the testing in order to provide a pool of data large enough for the results to be statistically significant. The test data set was comprised of two types of data, measured and simulated. The measured data were acquired with a hand-held Radioisotope Identification Device (RIID) and simulated spectra were created using Gamma Detector Response and Analysis Software (GADRAS, Mitchell and Mattingly, Sandia National Laboratory). GADRAS uses a one-dimensional discrete ordinate calculation to simulate gamma-ray spectra. The measured and simulated spectra have been analyzed and compared. This paper will discuss the results of the comparison and offer explanations for spectral differences.
Date: June 28, 2010
Creator: Jeffcoat, R. & Salaymeh, S.
Object Type: Article
System: The UNT Digital Library
Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons (open access)

Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic …
Date: April 28, 2010
Creator: Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P. et al.
Object Type: Report
System: The UNT Digital Library
Taiwan: Major U.S. Arms Sales Since 1990 (open access)

Taiwan: Major U.S. Arms Sales Since 1990

This CRS Report discusses U.S. security assistance for Taiwan, formally called the Republic of China (ROC), particularly policy issues for Congress. It also lists sales of major defense articles and services to Taiwan, as approved by the President and notified to Congress since 1990. This report uses a variety of unclassified consultations and citations in the United States and Taiwan.
Date: September 28, 2010
Creator: Kan, Shirley A.
Object Type: Report
System: The UNT Digital Library
Iraq: Politics, Elections, and Benchmarks (open access)

Iraq: Politics, Elections, and Benchmarks

This report provides an overview of Iraq's political transition from the dictatorship of Saddam Hussein to a plural polity that encompasses varying sects and ideological and political factions. This report also addresses ongoing governmental instabilities and their causes, as well as U.S. concerns about possible Iranian influence in Iraq as U.S. forces depart the country.
Date: April 28, 2010
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
Budget Reconciliation Measures Enacted Into Law: 1980-2010 (open access)

Budget Reconciliation Measures Enacted Into Law: 1980-2010

This report identifies and briefly summarizes the 20 budget reconciliation measures enacted into law during the period covering 1980, when reconciliation procedures first were used by both chambers, through 2010, the last year of the 111th Congress.
Date: May 28, 2010
Creator: Keith, Robert
Object Type: Report
System: The UNT Digital Library
U.S. Nuclear Cooperation with India: Issues for Congress (open access)

U.S. Nuclear Cooperation with India: Issues for Congress

This report discusses the United States' relationship with India as it regards nuclear nonproliferation and cooperation. In particular, the report discusses the Atomic Energy Act, which President Bush signed into law on December 18, 2006, and which governs U.S. nuclear cooperation. The report also discusses other related legislation as well as issues regarding U.S. nuclear trade with India.
Date: October 28, 2010
Creator: Kerr, Paul K.
Object Type: Report
System: The UNT Digital Library
Nuclear Cooperation with Other Countries: A Primer (open access)

Nuclear Cooperation with Other Countries: A Primer

This report discusses section 123 of the Atomic Energy Act (AEA), the specific requirements of which must be met in order for the United States to engage in civilian nuclear cooperation with other states. The AEA also provides for exemptions to these requirements, export control licensing procedures, and criteria for terminating cooperation.
Date: May 28, 2010
Creator: Kerr, Paul K. & Nikitin, Mary Beth
Object Type: Report
System: The UNT Digital Library
Y-12 81-10 Area Site Characterization Report 5095-SR-01-1 (open access)

Y-12 81-10 Area Site Characterization Report 5095-SR-01-1

5095-SR-01-1 Y-12 81-10 Area Site Characterization Report
Date: September 28, 2010
Creator: King, D. A.
Object Type: Report
System: The UNT Digital Library
Measurement of UO2F2 Samples Containing 2 Different Isotopic Compositions (open access)

Measurement of UO2F2 Samples Containing 2 Different Isotopic Compositions

None
Date: July 28, 2010
Creator: Kips, R
Object Type: Report
System: The UNT Digital Library
SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS (open access)

SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

None
Date: April 28, 2010
Creator: Koopman, David
Object Type: Report
System: The UNT Digital Library
SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS (open access)

SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

Phase III simulant flowsheet testing was completed using the latest composition estimates for SB6/Tank 40 feed to DWPF. The goals of the testing were to determine reasonable operating conditions and assumptions for the startup of SB6 processing in the DWPF. Testing covered the region from 102-159% of the current DWPF stoichiometric acid equation. Nitrite ion concentration was reduced to 90 mg/kg in the SRAT product of the lowest acid run. The 159% acid run reached 60% of the DWPF Sludge Receipt and Adjustment Tank (SRAT) limit of 0.65 lb H2/hr, and then sporadically exceeded the DWPF Slurry Mix Evaporator (SME) limit of 0.223 lb H2/hr. Hydrogen generation rates peaked at 112% of the SME limit, but higher than targeted wt% total solids levels may have been partially responsible for rates seen. A stoichiometric factor of 120% met both objectives. A processing window for SB6 exists from 102% to something close to 159% based on the simulant results. An initial recommendation for SB6 processing is at 115-120% of the current DWPF stoichiometric acid equation. The addition of simulated Actinide Removal Process (ARP) and Modular Caustic Side Solvent Extraction Unit (MCU) streams to the SRAT cycle had no apparent impact on the …
Date: April 28, 2010
Creator: Koopman, David
Object Type: Report
System: The UNT Digital Library
SLUDGE BATCH 6/TANK 51 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS (open access)

SLUDGE BATCH 6/TANK 51 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

Qualification simulant testing was completed to determine appropriate processing conditions and assumptions for the Sludge Batch 6 (SB6) Shielded Cells demonstration of the DWPF flowsheet using the qualification sample from Tank 51 for SB6 after SRNL washing. It was found that an acid addition window of 105-139% of the DWPF acid equation (100-133% of the Koopman minimum acid equation) gave acceptable Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) results for nitrite destruction and hydrogen generation. Hydrogen generation occurred continuously after acid addition in three of the four tests. The three runs at 117%, 133%, and 150% stoichiometry (Koopman) were all still producing around 0.1 lb hydrogen/hr at DWPF scale after 42 hours of boiling in the SRAT. The 150% acid run reached 110% of the DWPF SRAT limit of 0.65 lb H{sub 2}/hr, and the 133% acid run reached 75% of the DWPF SME limit of 0.223 lb H{sub 2}/hr. Conversely, nitrous oxide generation was subdued compared to previous sludge batches, staying below 25 lb/hr in all four tests or about a fourth as much as in comparable SB4 testing. Two other processing issues were noted. First, incomplete mercury suspension impacted mercury stripping from the SRAT …
Date: April 28, 2010
Creator: Koopman, David & Best, David
Object Type: Report
System: The UNT Digital Library
Thin Silicon MEMS Contact-Stress Sensor (open access)

Thin Silicon MEMS Contact-Stress Sensor

This thin, MEMS contact-stress sensor continuously and accurately measures time-varying, solid interface loads over tens of thousands of load cycles. The contact-stress sensor is extremely thin (150 {mu}m) and has a linear output with an accuracy of {+-} 1.5% FSO.
Date: May 28, 2010
Creator: Kotovksy, J; Tooker, A & Horsley, D
Object Type: Article
System: The UNT Digital Library
Status Summary of 3He and Neutron Detection Alternatives for Homeland Security (open access)

Status Summary of 3He and Neutron Detection Alternatives for Homeland Security

This is a short summary whitepaper on results of our alternatives work: Neutron detection is an important aspect of interdiction of radiological threats for homeland security purposes since plutonium, a material used for nuclear weapons, is a significant source of fission neutrons [Kouzes 2005]. Because of the imminent shortage of 3He, which is used in the most commonly deployed neutron detectors, a replacement technology for neutron detection is required for most detection systems in the very near future [Kouzes 2009a]. For homeland security applications, neutron false alarms from a detector can result in significant impact. This puts a strong requirement on any neutron detection technology not to generate false neutron counts in the presence of a large gamma ray-only source [Kouzes et al. 2008].
Date: April 28, 2010
Creator: Kouzes, Richard T. & Ely, James H.
Object Type: Report
System: The UNT Digital Library
Intermountain Industrial Assessment Center (open access)

Intermountain Industrial Assessment Center

The U. S. Department of Energy’s Intermountain Industrial Assessment Center (IIAC) at the University of Utah has been providing eligible small- and medium-sized manufacturers with no-cost plant assessments since 2001, offering cost-effective recommendations for improvements in the areas of energy efficiency, pollution prevention, and productivity improvement.
Date: May 28, 2010
Creator: Krahenbuhl, Melinda
Object Type: Report
System: The UNT Digital Library
Advances and Current Challenges in the Theory of Zonal-Flow Generation (open access)

Advances and Current Challenges in the Theory of Zonal-Flow Generation

Some remarks are made about the use of modern statistical formalism in the calculation of the zonal-flow growth rate and the backreaction of zonal flows on drift waves.
Date: September 28, 2010
Creator: Krommes, John E.
Object Type: Report
System: The UNT Digital Library
WASTE LOADING ENHANCEMENTS FOR HANFORD LAW GLASSES VLS-10R1790-1 FINAL REPORT REV 0 12/1/2010 (open access)

WASTE LOADING ENHANCEMENTS FOR HANFORD LAW GLASSES VLS-10R1790-1 FINAL REPORT REV 0 12/1/2010

About 50 million gallons of high-level mixed waste is currently stored in underground tanks at The United States Department of Energy's (DOE's) Hanford site in the State of Washington. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) will provide DOE's Office of River Protection (ORP) with a means of treating this waste by vitrification for subsequent disposal. The tank waste will be separated into low- and high-activity waste fractions, which will then be vitrified respectively into Immobilized Low Activity Waste (ILAW) and Immobilized High Level Waste (IHLW) products. The ILAW product will be disposed in an engineered facility on the Hanford site while the IHLW product will likely be directed to a national deep geological disposal facility for high-level nuclear waste. The ILAW and IHLW products must meet a variety of requirements with respect to protection of the environment before they can be accepted for disposal. The Office of River Protection is currently examining options to optimize the Low Activity Waste (LAW) Facility and LAW glass waste form. One option under evaluation is to enhance the waste processing rate of the vitrification plant currently under construction. It is likely that the capacity of the LAW vitrification plant can be …
Date: December 28, 2010
Creator: Kruger, A. A.; Muller, I. S.; Joseph, I.; Matlack, K. S.; Gan, H. & Pegg, I. L.
Object Type: Report
System: The UNT Digital Library
Thermodynamic Data for Geochemical Modeling of Carbonate Reactions Associated with CO2 Sequestration – Literature Review (open access)

Thermodynamic Data for Geochemical Modeling of Carbonate Reactions Associated with CO2 Sequestration – Literature Review

Permanent storage of anthropogenic CO2 in deep geologic formations is being considered as a means to reduce the concentration of atmospheric CO2 and thus its contribution to global climate change. To ensure safe and effective geologic sequestration, numerous studies have been completed of the extent to which the CO2 migrates within geologic formations and what physical and geochemical changes occur in these formations when CO2 is injected. Sophisticated, computerized reservoir simulations are used as part of field site and laboratory CO2 sequestration studies. These simulations use coupled multiphase flow-reactive chemical transport models and/or standalone (i.e., no coupled fluid transport) geochemical models to calculate gas solubility, aqueous complexation, reduction/oxidation (redox), and/or mineral solubility reactions related to CO2 injection and sequestration. Thermodynamic data are critical inputs to modeling geochemical processes. The adequacy of thermodynamic data for carbonate compounds has been identified as an important data requirement for the successful application of these geochemical reaction models to CO2 sequestration. A review of thermodynamic data for CO2 gas and carbonate aqueous species and minerals present in published data compilations and databases used in geochemical reaction models was therefore completed. Published studies that describe mineralogical analyses from CO2 sequestration field and natural analogue sites and …
Date: September 28, 2010
Creator: Krupka, Kenneth M.; Cantrell, Kirk J. & McGrail, B. Peter
Object Type: Report
System: The UNT Digital Library
Measurement of the gamma gamma* to eta_c transition form factor (open access)

Measurement of the gamma gamma* to eta_c transition form factor

The authors study the reaction e{sup +}e{sup -} {yields} e{sup +}e{sup -} {eta}{sub c}, {eta}{sub c} {yields} K{sub S}K{sup {+-}}{pi}{sup {-+}} and obtain {eta}{sub c} mass and width values 2982.2 {+-} 0.4 {+-} 1.6 MeV/c{sup 2} and 31.7 {+-} 1.2 {+-} 0.8 MeV, respectively. They find {Lambda}({eta}{sub c} {yields} {gamma}{gamma}){Beta}({eta}{sub c} {yields} K{bar K}{pi}) = 0.374 {+-} 0.009 {+-} 0.031 keV, and measure the {gamma}{gamma}* {yields} {eta}{sub c} transition form factor in the momentum transfer range from 2 to 50 GeV{sup 2}. The analysis is based on 469 fb{sup -1} of integrated luminosity collected at PEP-II with the BABAR detector at e{sup +}e{sup -} center-of-mass energies near 10.6 GeV.
Date: April 28, 2010
Creator: Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E. et al.
Object Type: Article
System: The UNT Digital Library
Final Technical Report 09 LW 112 (open access)

Final Technical Report 09 LW 112

Since the development of new antibiotics is out-paced by the emergence of bacterial resistance to existing antibiotics, it is crucial to understand the genetic mechanisms underlying resistance existing antibiotics. At the center of this mystery is a poorly understood phenomenon, heteroresistance: the coexistence of multiple subpopulations with varying degrees of antibiotic resistance. A better understanding of the fundamental basis of heteroresistance could result in sorely needed breakthroughs in treatment options. This project proposed to leverage a novel microfluidic (microchemostat) technology to probe the heteroresistance phenomenon in bacteria, with the aim of restoring the efficacy of existing {beta}-lactam antibiotics. The clinically important bacteria Methicillin Resistant S. aureus (MRSA) was used as the test case of bacteria that exhibits antibiotic heteroresistance. MRSA is difficult to treat because it is resistant to all {beta}-lactam antibiotics, as well as other classes of antimicrobials. Whereas {beta}-lactams such as methicillin and oxacillin are the preferred antibiotics to treat S. aureus infections due to their efficacy and low side effects, accurate determination and use of oxacillin/methicillin dosage is hampered by heteroresistance. In fact, invasive MRSA infections now account for about 95,000 deaths per year, a number that exceeds the deaths due to either influenza or HIV (12). …
Date: November 28, 2010
Creator: Lenhoff, R J
Object Type: Report
System: The UNT Digital Library
Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan (open access)

Assessment of China's Energy-Saving and Emission-Reduction Accomplishments and Opportunities During the 11th Five Year Plan

During the period 1980 to 2002, China experienced a 5% average annual reduction in energy consumption per unit of gross domestic product (GDP). The period 2002-2005 saw a dramatic reversal of the historic relationship between energy use and GDP growth: energy use per unit of GDP increased an average of 3.8% per year during this period (NBS, various years). China's 11th Five Year Plan (FYP), which covers the period 2006-2010, required all government divisions at different levels to reduce energy intensity by 20% in five years in order to regain the relationship between energy and GDP growth experienced during the 1980s and 1990s. This report provides an assessment of selected policies and programs that China has instituted in its quest to fulfill the national goal of a 20% reduction in energy intensity by 2010. The report finds that China has made substantial progress toward its goal of achieving 20% energy intensity reduction from 2006 to 2010 and that many of the energy-efficiency programs implemented during the 11th FYP in support of China's 20% energy/GDP reduction goal appear to be on track to meet - or in some cases even exceed - their energy-saving targets. It appears that most of the …
Date: April 28, 2010
Creator: Levine, Mark D.; Price, Lynn; Zhou, Nan; Fridley, David; Aden, Nathaniel; Lu, Hongyou et al.
Object Type: Report
System: The UNT Digital Library
Physical Property Analysis and Report for Sediments at 100-BC-5 Operable Unit, Boreholes C7505, C7506, C7507, and C7665 (open access)

Physical Property Analysis and Report for Sediments at 100-BC-5 Operable Unit, Boreholes C7505, C7506, C7507, and C7665

Between October 14, 2009 and February 22, 2010 sediment samples were received from 100-BC Decision Unit for geochemical studies. This is an analytical data report for sediments received from CHPRC at the 100 BC 5 OU. The analyses for this project were performed at the 325 building located in the 300 Area of the Hanford Site. The analyses were performed according to Pacific Northwest National Laboratory (PNNL) approved procedures and/or nationally recognized test procedures. The data sets include the sample identification numbers, analytical results, estimated quantification limits (EQL), and quality control data. The preparatory and analytical quality control requirements, calibration requirements, acceptance criteria, and failure actions are defined in the on-line QA plan 'Conducting Analytical Work in Support of Regulatory Programs' (CAW). This QA plan implements the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD) for PNNL.
Date: September 28, 2010
Creator: Lindberg, Michael J.
Object Type: Report
System: The UNT Digital Library
Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage (open access)

Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage

This program was devoted to significantly extending the limits of hydrogen storage technology for practical transportation applications. To meet the hydrogen capacity goals set forth by the DOE, solid-state materials consisting of light elements were developed. Many light element compounds are known that have high capacities. However, most of these materials are thermodynamically too stable, and they release and store hydrogen much too slowly for practical use. In this project we developed new light element chemical systems that have high hydrogen capacities while also having suitable thermodynamic properties. In addition, we developed methods for increasing the rates of hydrogen exchange in these new materials. The program has significantly advanced (1) the application of combined hydride systems for tuning thermodynamic properties and (2) the use of nanoengineering for improving hydrogen exchange. For example, we found that our strategy for thermodynamic tuning allows both entropy and enthalpy to be favorably adjusted. In addition, we demonstrated that using porous supports as scaffolds to confine hydride materials to nanoscale dimensions could improve rates of hydrogen exchange by > 50x. Although a hydrogen storage material meeting the requirements for commercial development was not achieved, this program has provided foundation and direction for future efforts. More …
Date: February 28, 2010
Creator: Liu, Ping & Vajo, John J.
Object Type: Report
System: The UNT Digital Library
Measuring the Density of a Molecular Cluster Injector via Visible Emission from an Electron Beam (open access)

Measuring the Density of a Molecular Cluster Injector via Visible Emission from an Electron Beam

A method to measure the density distribution of a dense hydrogen gas jet is pre- sented. A Mach 5.5 nozzle is cooled to 80K to form a flow capable of molecular cluster formation. A 250V, 10mA electron beam collides with the jet and produces Hα emission that is viewed by a fast camera. The high density of the jet, several 10<sup>16</sup>cm<sup>-3</sup>, results in substantial electron depletion, which attenuates the H<sub>α</sub> emission. The attenuated emission measurement, combined with a simplified electron-molecule collision model, allows us to determine the molecular density profile via a simple iterative calculation.
Date: June 28, 2010
Creator: Lundberg, D. P.; Kaita, R.; Majeski, R. M. & Stotler, D. P.
Object Type: Report
System: The UNT Digital Library