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ACRF Instrumentation Status: New, Current, and Future November-December 2006 (open access)

ACRF Instrumentation Status: New, Current, and Future November-December 2006

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Program Climate Research Facility instrumentation status. The report is divided into four sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) Small Business Innovation Research instrument development.
Date: December 1, 2006
Creator: Liljegren, J. C.
System: The UNT Digital Library
Advanced Fuel Cycle Economic Sensitivity Analysis (open access)

Advanced Fuel Cycle Economic Sensitivity Analysis

A fuel cycle economic analysis was performed on four fuel cycles to provide a baseline for initial cost comparison using the Gen IV Economic Modeling Work Group G4 ECON spreadsheet model, Decision Programming Language software, the 2006 Advanced Fuel Cycle Cost Basis report, industry cost data, international papers, the nuclear power related cost study from MIT, Harvard, and the University of Chicago. The analysis developed and compared the fuel cycle cost component of the total cost of energy for a wide range of fuel cycles including: once through, thermal with fast recycle, continuous fast recycle, and thermal recycle.
Date: December 1, 2006
Creator: Shropshire, David; Williams, Kent; Smith, J. D. & Boore, Brent
System: The UNT Digital Library
Advanced Test Reactor LEU Fuel Conversion Feasibility Study (2006 Annual Report) (open access)

Advanced Test Reactor LEU Fuel Conversion Feasibility Study (2006 Annual Report)

The Advanced Test Reactor (ATR) is a high power density and high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth with a maximum unperturbed thermal neutron flux rating of 1.0 x 1015 n/cm2–s. Because of these operating parameters, and the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. The present work investigates the necessary modifications and evaluates the subsequent operating effects of this conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed and validated for a fuel cycle burnup comparison analysis. Using the current HEU U 235 enrichment of 93.0 % as a baseline, an analysis can be performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff between the HEU core and the LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the U-235 loading in the LEU core, such that the differences in K-eff and heat profile …
Date: December 1, 2006
Creator: Chang, Gray S.; Ambrosek, Richard G. & Lillo, Misti A.
System: The UNT Digital Library
A brief comparison between grid based real space algorithms andspectrum algorithms for electronic structure calculations (open access)

A brief comparison between grid based real space algorithms andspectrum algorithms for electronic structure calculations

Quantum mechanical ab initio calculation constitutes the biggest portion of the computer time in material science and chemical science simulations. As a computer center like NERSC, to better serve these communities, it will be very useful to have a prediction for the future trends of ab initio calculations in these areas. Such prediction can help us to decide what future computer architecture can be most useful for these communities, and what should be emphasized on in future supercomputer procurement. As the size of the computer and the size of the simulated physical systems increase, there is a renewed interest in using the real space grid method in electronic structure calculations. This is fueled by two factors. First, it is generally assumed that the real space grid method is more suitable for parallel computation for its limited communication requirement, compared with spectrum method where a global FFT is required. Second, as the size N of the calculated system increases together with the computer power, O(N) scaling approaches become more favorable than the traditional direct O(N{sup 3}) scaling methods. These O(N) methods are usually based on localized orbital in real space, which can be described more naturally by the real space basis. …
Date: December 1, 2006
Creator: Wang, Lin-Wang
System: The UNT Digital Library
Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Marine Climates; January 2006 - December 2006 (open access)

Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Marine Climates; January 2006 - December 2006

The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Marine Climate Region on a cost neutral basis.
Date: December 1, 2006
Creator: Building America Industrialized Housing Partnership
System: The UNT Digital Library
Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Mixed-Humid Climates; January 2006 - December 2006 (open access)

Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Mixed-Humid Climates; January 2006 - December 2006

The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in the Mixed-Humid Climate Region on a cost-neutral basis.
Date: December 1, 2006
Creator: Building America Industrialized Housing Partnership
System: The UNT Digital Library
Case Studies from the Climate Technology Partnership: Landfill Gas Projects in South Korea and Lessons Learned (open access)

Case Studies from the Climate Technology Partnership: Landfill Gas Projects in South Korea and Lessons Learned

This paper examines landfill gas projects in South Korea. Two case studies provide concrete examples of lessons learned and offer practical guidance for future projects.
Date: December 1, 2006
Creator: Larney, C.; Heil, M. & Ha, G. A.
System: The UNT Digital Library
Chiral multichromic single crystals for optical devices (LDRD 99406). (open access)

Chiral multichromic single crystals for optical devices (LDRD 99406).

This report summarizes our findings during the study of a novel system that yields multi-colored materials as products. This system is quite unusual as it leads to multi-chromic behavior in single crystals, where one would expect that only a single color would exist. We have speculated that these novel solids might play a role in materials applications such as non-linear optics, liquid crystal displays, piezoelectric devices, and other similar applications. The system examined consisted of a main-group alkyl compound (a p block element such as gallium or aluminum) complexed with various organic di-imines. The di-imines had substituents of two types--either alkyl or aromatic groups attached to the nitrogen atoms. We observed that single crystals, characterized by X-ray crystallography, were obtained in most cases. Our research during January-July, 2006, was geared towards understanding the factors leading to the multi-chromic nature of the complexes. The main possibilities put forth initially considered (a) the chiral nature of the main group metal, (b) possible reduction of the metal to a lower-valent, radical state, (c) the nature of the ligand(s) attached to the main group metal, and (d) possible degradation products of the ligand leading to highly-colored products. The work carried out indicates that the …
Date: December 1, 2006
Creator: Kemp, Richard Alan & Felix, Ana M. (University of New Mexico, Albuquerque, NM)
System: The UNT Digital Library
Communal spaces: aggregation and integration in the Mogollon Region of the United States Southwest (open access)

Communal spaces: aggregation and integration in the Mogollon Region of the United States Southwest

Aggregation and integration are processes that occur in human societies throughout the globe. An informative example of population aggregation and social integration can be observed in the North American desert borderlands from A.D. 250 to 1450 in the area known as the Mogollon region. In fact, Mogollon communities oscillated from smaller social groups into larger ones and dispersed into smaller groups only to form larger ones again. For this reason, examining the groups of people living in the Mogollon region provides a magnified view of social change over a substantial period. Understanding patterns of aggregation and integration provides researchers with the promise for research into the nature of these phenomena. In general, the Mogollon region is characterized by limited water supplies and low average annual precipitation. However, pockets of the Mogollon area, including the Mimbres valley and the Gila River valley, represent oases, where permanent rivers and their associated tributaries allowed for the pursuit of agricultural endeavors and access to a wide variety of wild plant and animal resources. The areas with these kinds of potential became population centers for previously dispersed groups of people living in the region. These people exploited natural resources and practiced agriculture in areas surrounding …
Date: December 1, 2006
Creator: Nisengard, Jennifer E.
System: The UNT Digital Library
Compact-range coordinate system established using a laser tracker. (open access)

Compact-range coordinate system established using a laser tracker.

Establishing a Cartesian coordinate reference system for an existing Compact Antenna Range using the parabolic reflector is presented. A SMX (Spatial Metrix Corporation) M/N 4000 laser-based coordinate measuring system established absolute coordinates for the facility. Electric field characteristics with positional movement correction are evaluated. Feed Horn relocation for alignment with the reflector axis is also described. Reference points are established for follow-on non-laser alignments utilizing a theodolite.
Date: December 1, 2006
Creator: Gallegos, Floyd H. & Bryce, Edwin Anthony
System: The UNT Digital Library
Comparison of Sludge Digestion Methods for High Organic Hanford Tank 241-C-204 (open access)

Comparison of Sludge Digestion Methods for High Organic Hanford Tank 241-C-204

This report presents the results of an investigation into methods for digesting sludge in tank 241-C-204 at the Hanford Site in south-central Washington State. The objective of this study was to compare the recovery of uranium, neptunium, and plutonium using three digestion methods: EPA Method 3052, EPA Method 3050B, and alkaline fusion. Results show that EPA Method 3052, microwave assisted acid digestion, is the most efficient digestion method with higher recoveries for both uranium and plutonium. This may also be the case for neptunium; however, the analytical results are uncertain for this element. The microwave digestion method also has the added benefits of being quicker and producing less waste, which lowers the overall cost per sample. Further testing with samples from other tanks will confirm that microwave assisted digestion is a viable method of digesting Hanford tank sludges (including those with a high organic content) for chemical analysis.
Date: December 1, 2006
Creator: Lindberg, Michael J. & Deutsch, William J.
System: The UNT Digital Library
Comparison of the Energy Efficiency Prescribed by ASHRAE/ANSI/IESNA Standard 90.1-1999 and ASHRAE/ANSI/IESNA Standard 90.1-2004 (open access)

Comparison of the Energy Efficiency Prescribed by ASHRAE/ANSI/IESNA Standard 90.1-1999 and ASHRAE/ANSI/IESNA Standard 90.1-2004

This document presents the qualitative comparison of DOE’s formal determination of energy savings of ANSI/ASHRAE/IESNA Standard 90.1-2004. The term “qualitative” is used in the sense of identifying whether or not changes have a positive, negative, or neutral impact on energy efficiency of the standard, with no attempt made to quantify that impact. A companion document will present the quantitative comparison of DOE’s determination. The quantitative comparison will be based on whole building simulation of selected building prototypes in selected climates. This document presents a comparison of the energy efficiency requirements in ANSI/ASHRAE/IESNA 90.1-1999 (herein referred to as Standard 90.1-1999) and ANSI/ASHRAE/IESNA 90.1-2004 (herein referred to as Standard 90.1-2004). The comparison was done through a thorough review of all addenda to Standard 90.1-1999 that were included in the published ANSI/ASHRAE/IESNA Standard 90.1-2001 (herein referred to as Standard 90.1-2001) and also all addenda to Standard 90.1-2001 that were included in the published Standard 90.1-2004. A summary table showing the impact of each addendum is provided. Each addendum to both Standards 90.1-1999 and 90.1-2001 was evaluated as to its impact on the energy efficiency requirements of the standard (greater efficiency, lesser efficiency) and as to significance. The final section of this document summarizes …
Date: December 1, 2006
Creator: Halverson, Mark A.; Liu, Bing; Richman, Eric E. & Winiarski, David W.
System: The UNT Digital Library
Completion Report for Well ER-16-1 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain (open access)

Completion Report for Well ER-16-1 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain

Well ER-16-1 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in June and July 2005 as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit, Number 99. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology of the Shoshone Mountain area, especially in the older Tertiary and pre-Tertiary strata. The main 46.99-centimeter hole was drilled to a depth of 702.9 meters and cased with 33.97-centimeter casing to 663.7 meters. The hole diameter was then decreased to 31.1 centimeters, and the well was drilled to total depth of 1,220.7 meters. A completion string set at the depth of 1,162.4 meters consisted of 13.97-centimeter stainless-steel casing, with one continuous slotted interval open to the lower carbonate aquifer. The fluid level in the borehole soon dropped, so the borehole was deepened in July 2006. To deepen the borehole, the slotted section was cemented and a 12.1-centimeter hole was drilled through the bottom of the completion string to the new total depth of 1,391.7 meters, …
Date: December 1, 2006
Creator: National Security Technologies, LLC
System: The UNT Digital Library
Completion Report for Well ER-16-1 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain (open access)

Completion Report for Well ER-16-1 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain

Well ER-16-1 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in June and July 2005 as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit, Number 99. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology of the Shoshone Mountain area, especially in the older Tertiary and pre-Tertiary strata. The main 46.99-centimeter hole was drilled to a depth of 702.9 meters and cased with 33.97-centimeter casing to 663.7 meters. The hole diameter was then decreased to 31.1 centimeters, and the well was drilled to total depth of 1,220.7 meters. A completion string set at the depth of 1,162.4 meters consisted of 13.97-centimeter stainless-steel casing, with one continuous slotted interval open to the lower carbonate aquifer. The fluid level in the borehole soon dropped, so the borehole was deepened in July 2006. To deepen the borehole, the slotted section was cemented and a 12.1-centimeter hole was drilled through the bottom of the completion string to the new total depth of 1,391.7 meters, …
Date: December 1, 2006
Creator: Services, NSTec Geology
System: The UNT Digital Library
Contribution to the nsac long-range plan entitled (open access)

Contribution to the nsac long-range plan entitled

This is a time of great opportunity in nuclear spectroscopy. The development of radioactive beam capabilities around the world is opening a new landscape for discovery, and the connections between nuclear structure studies and astrophysics, neutrino physics, and physics beyond the standard model are stronger than ever. New detector technologies are evolving which can meet the challenges of the new generation of experiments. Leading these is the technology of ''{gamma}-ray tracking'' which can revolutionize {gamma}-ray spectroscopy in a way that large arrays of {gamma} detectors did a decade ago. During the last few years this technology has been shown feasible and GRETINA a 1{pi} detector is under construction. However, the momentum in developing this technology to its full potential must continue towards GRETA, a full 4{pi} calorimeter. GRETA will carry {gamma}-ray spectroscopy into the next generation where it will be needed to fully exploit the science opportunities at radioactive beam facilities and increase the reach of stable beam facilities. In addition, {gamma}-ray tracking technology will have important applications for science, medicine, and homeland security.
Date: December 1, 2006
Creator: GRETINA Physics Working Group, the GRETINA Advisor
System: The UNT Digital Library
Corrective Action Decision Document for Corrective Action Unit 168: Area 25 and 26 Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada, Rev. No.: 2 with Errata Sheet (open access)

Corrective Action Decision Document for Corrective Action Unit 168: Area 25 and 26 Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada, Rev. No.: 2 with Errata Sheet

This Corrective Action Decision Document has been prepared for Corrective Action Unit (CAU) 168: Area 25 and 26, Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada. The purpose of this Corrective Action Decision Document is to identify and provide a rationale for the selection of a recommended corrective action alternative for each corrective action site (CAS) within CAU 168. The corrective action investigation (CAI) was conducted in accordance with the ''Corrective Action Investigation Plan for Corrective Action Unit 168: Area 25 and 26, Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada'', as developed under the ''Federal Facility Agreement and Consent Order'' (1996). Corrective Action Unit 168 is located in Areas 25 and 26 of the Nevada Test Site, Nevada and is comprised of the following 12 CASs: CAS 25-16-01, Construction Waste Pile; CAS 25-16-03, MX Construction Landfill; CAS 25-19-02, Waste Disposal Site; CAS 25-23-02, Radioactive Storage RR Cars; CAS 25-23-13, ETL - Lab Radioactive Contamination; CAS 25-23-18, Radioactive Material Storage; CAS 25-34-01, NRDS Contaminated Bunker; CAS 25-34-02, NRDS Contaminated Bunker; CAS 25-99-16, USW G3; CAS 26-08-01, Waste Dump/Burn Pit; CAS 26-17-01, Pluto Waste Holding Area; and CAS 26-19-02, Contaminated Waste Dump No.2. Analytes detected during the CAI were …
Date: December 1, 2006
Creator: Wickline, Alfred
System: The UNT Digital Library
Corrective Action Investigation Plan for Corrective Action Unit 190: Contaminated Waste Sites Nevada Test Site, Nevada, Rev. No.: 0 (open access)

Corrective Action Investigation Plan for Corrective Action Unit 190: Contaminated Waste Sites Nevada Test Site, Nevada, Rev. No.: 0

Corrective Action Unit (CAU) 190 is located in Areas 11 and 14 of the Nevada Test Site, which is 65 miles northwest of Las Vegas, Nevada. Corrective Action Unit 190 is comprised of the four Corrective Action Sites (CASs) listed below: (1) 11-02-01, Underground Centrifuge; (2) 11-02-02, Drain Lines and Outfall; (3) 11-59-01, Tweezer Facility Septic System; and (4) 14-23-01, LTU-6 Test Area. These sites are being investigated because existing information is insufficient on the nature and extent of potential contamination to evaluate and recommend corrective action alternatives. Additional information will be obtained before evaluating corrective action alternatives and selecting the appropriate corrective action for each CAS by conducting a corrective action investigation (CAI). The results of the field investigation will support a defensible evaluation of viable corrective action alternatives that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed on August 24, 2006, by representatives of the Nevada Division of Environmental Protection; U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office; Stoller-Navarro Joint Venture, and National Security Technologies, LLC. The DQO process was used to identify and define the type, amount, and quality of …
Date: December 1, 2006
Creator: Wickline, Alfred
System: The UNT Digital Library
Demand Response For Power System Reliability: FAQ (open access)

Demand Response For Power System Reliability: FAQ

Demand response is the most underutilized power system reliability resource in North America. Technological advances now make it possible to tap this resource to both reduce costs and improve. Misconceptions concerning response capabilities tend to force loads to provide responses that they are less able to provide and often prohibit them from providing the most valuable reliability services. Fortunately this is beginning to change with some ISOs making more extensive use of load response. This report is structured as a series of short questions and answers that address load response capabilities and power system reliability needs. Its objective is to further the use of responsive load as a bulk power system reliability resource in providing the fastest and most valuable ancillary services.
Date: December 1, 2006
Creator: Kirby, Brendan J
System: The UNT Digital Library
The effects of emotional states and traits on risky decision-making. (open access)

The effects of emotional states and traits on risky decision-making.

Understanding the role of emotional states is critical for predicting the kind of decisions people will make in risky situations. Currently, there is little understanding as to how emotion influences decision-making in situations such as terrorist attacks, natural disasters, pandemics, and combat. To help address this, we used behavioral and neuroimaging methods to examine how emotion states and traits influence decisions. Specifically, this study used a wheel of fortune behavioral task and functional magnetic resonance imaging (fMRI) to examine the effects of emotional states and traits on decision-making pertaining to the degree of risk people are willing to make in specific situations. The behavioral results are reported here. The neural data requires additional time to analyze and will be reported at a future date. Biases caused by emotion states and traits were found regarding the likelihood of making risky decisions. The behavioral results will help provide a solid empirical foundation for modeling the effects of emotion on decision in risky situations.
Date: December 1, 2006
Creator: Bernard, Michael Lewis & Smith, Bruce W., 1959- (,University of New Mexico, Albuquerque, NM-)
System: The UNT Digital Library
Efficient MATLAB computations with sparse and factored tensors. (open access)

Efficient MATLAB computations with sparse and factored tensors.

In this paper, the term tensor refers simply to a multidimensional or N-way array, and we consider how specially structured tensors allow for efficient storage and computation. First, we study sparse tensors, which have the property that the vast majority of the elements are zero. We propose storing sparse tensors using coordinate format and describe the computational efficiency of this scheme for various mathematical operations, including those typical to tensor decomposition algorithms. Second, we study factored tensors, which have the property that they can be assembled from more basic components. We consider two specific types: a Tucker tensor can be expressed as the product of a core tensor (which itself may be dense, sparse, or factored) and a matrix along each mode, and a Kruskal tensor can be expressed as the sum of rank-1 tensors. We are interested in the case where the storage of the components is less than the storage of the full tensor, and we demonstrate that many elementary operations can be computed using only the components. All of the efficiencies described in this paper are implemented in the Tensor Toolbox for MATLAB.
Date: December 1, 2006
Creator: Bader, Brett William & Kolda, Tamara Gibson (Sandia National Lab, Livermore, CA)
System: The UNT Digital Library
Energy Efficiency of the 2003 International Energy Conservation Code in West Virginia (open access)

Energy Efficiency of the 2003 International Energy Conservation Code in West Virginia

This report estimate the energy savings, economic impacts, and pollution reduction from adopting the 2003 International Code Council’s 2003 International Energy Conservation Code (as the mandatory residential energy efficiency code in the state of West Virginia. The state currently allows a less stringent replacement option. This report addresses the impacts for low-rise residential buildings only.
Date: December 1, 2006
Creator: Lucas, Robert G.
System: The UNT Digital Library
Engineered Natural Geosorbents for In Situ Immobilization of DNAPLs and Heavy Metals (open access)

Engineered Natural Geosorbents for In Situ Immobilization of DNAPLs and Heavy Metals

Extensive subsurface contamination by dense non-aqueous phase liquid (DNAPL) organic solvents and heavy metals is common place at many DOE facilities. Poor performances and excessive costs have made traditional technologies and approaches less than satisfactory for remediation of such sites. It is increasingly apparent that marginal improvements in conventional methods and approaches will not suffice for clean up of many contaminated DOE sites. Innovative approaches using new and/or existing technologies in more efficient and cost-effective ways are thus urgently required.
Date: December 1, 2006
Creator: Weber, Walter J.; Fair, Gordon M. & Boyce, Earnest
System: The UNT Digital Library
Fatigue Testing of Metallurgically-Bonded EBR-II Superheater Tubes (open access)

Fatigue Testing of Metallurgically-Bonded EBR-II Superheater Tubes

Fatigue crack growth tests were performed on 2¼Cr-1Mo steel specimens machined from ex-service Experimental Breeder Reactor – II (EBR-II) superheater duplex tubes. The tubes had been metallurgically bonded with a 100 µm thick Ni interlayer; the specimens incorporated this bond layer. Tests were performed at room temperature in air and at 400°C in air and humid Ar; cracks were grown at varied levels of constant ?K. Crack growth tests at a range of ?K were also performed on specimens machined from the shell of the superheater. In all conditions the presence of the Ni interlayer was found to result in a net retardation of growth as the crack passed through the interlayer. The mechanism of retardation was identified as a disruption of crack planarity and uniformity after passing through the porous interlayer. Full crack arrest was only observed in a single test performed at near-threshold ?K level (12 MPa?m) at 400°C. In this case the crack tip was blunted by oxidation of the base steel at the steel-interlayer interface.
Date: December 1, 2006
Creator: Totemeier, Terry C.
System: The UNT Digital Library
FLASH X-RAY (FXR) LINEAR INDUCTION ACCELERATOR (LIA) OPTIMIZATION Upgrade of the OTR Emittance Diagnostic (open access)

FLASH X-RAY (FXR) LINEAR INDUCTION ACCELERATOR (LIA) OPTIMIZATION Upgrade of the OTR Emittance Diagnostic

Knowing the electron beam parameters at the exit of an accelerator is critical for several reasons. Foremost is to optimize the application of the beam, which is flash radiography in the case of the FXR accelerator. The beam parameters not only determine the theoretical dose, x-ray spectrum, and radiograph resolution (spot size), they are required to calculate the final transport magnetic fields that focus the beam on the bremsstrahlung converter to achieve the theoretical limits. Equally important is the comparison of beam parameters to the design specifications. This comparison indicates the ''health'' of the accelerator, warning the operator when systems are deteriorating or failing. For an accelerator of the size and complexity of FXR, a large suite of diagnostics is normally employed to measure and/or infer beam parameters. These diagnostics are distributed throughout the accelerator and can require a large number of ''shots'' (measurements) to calculate a specific beam parameter. The OTR Emittance Diagnostic, however, has the potential to measure all but one of the beam parameters simultaneous at a specific location. Using measurements from a scan of a few shots, this final parameter can also be determined. Since first deployment, the OTR Emittance Diagnostic has been limited to measuring …
Date: December 1, 2006
Creator: Houck, T L & Wargo, P E
System: The UNT Digital Library