Design of a New Optical System for Alcator C-Mod Motional Stark Effect Diagnostic (open access)

Design of a New Optical System for Alcator C-Mod Motional Stark Effect Diagnostic

The motional Stark effect (MSE) diagnostic on Alcator C-Mod uses an in-vessel optical system (five lenses and three mirrors) to relay polarized light to an external polarimeter because port access limitations on Alcator C-Mod preclude a direct view of the diagnostic beam. The system experiences unacceptable, spurious drifts of order several degrees in measured pitch angle over the course of a run day. Recent experiments illuminated the MSE diagnostic with polarized light of fixed orientation as heat was applied to various optical elements. A large change in measured angle was observed as two particular lenses were heated, indicating that thermal-stress-induced birefringence is a likely cause of the spurious variability. Several new optical designs have been evaluated to eliminate the affected in-vessel lenses and to replace the focusing they provide with curved mirrors; however, ray tracing calculations imply that this method is not feasible. A new approach is under consideration that utilizes in situ calibrations with in-vessel reference polarized light sources. 2008 American Institute of Physics.
Date: November 12, 2009
Creator: Jinseok Ko, Steve Scott, Manfred Bitter, and Scott Lerner
Object Type: Report
System: The UNT Digital Library
Discretizing Transient Current Densities in the Maxwell Equations (open access)

Discretizing Transient Current Densities in the Maxwell Equations

None
Date: November 12, 2009
Creator: Stowell, M. L. & White, D. A.
Object Type: Article
System: The UNT Digital Library
Experimental basis for laser-plasma interactions in ignition hohlraums at the National Ignition Facility (open access)

Experimental basis for laser-plasma interactions in ignition hohlraums at the National Ignition Facility

A series of laser plasma interaction experiments at OMEGA (LLE, Rochester) using gas-filled hohlraums shed light on the behavior of stimulated Raman scattering and stimulated Brillouin scattering at various plasma conditions encountered in indirect drive ignition designs. We present detailed experimental results that quantify the density, temperature, and intensity thresholds for both of these instabilities. In addition to controlling plasma parameters, the National Ignition Campaign relies on optical beam smoothing techniques to mitigate backscatter. We show that polarization smoothing is effective at controlling backscatter. These results provide an experimental basis for forthcoming experiments on National Ignition Facility.
Date: November 12, 2009
Creator: Froula, D. H.; Divol, L.; London, R. A.; Berger, R. L.; Doeppner, T.; Meezan, N. B. et al.
Object Type: Article
System: The UNT Digital Library
Final Report - "UCM-Grid Service for User-Centric Monitoring" (open access)

Final Report - "UCM-Grid Service for User-Centric Monitoring"

The User Centric Monitoring (UCM) project was aimed at developing a toolkit that provides the Virtual Organization (VO) with tools to build systems that serve a rich set of intuitive job and application monitoring information to the VO's scientists so that they can be more productive. The tools help collect and serve the status and error information through a Web interface. The proposed UCM toolkit is composed of a set of library functions, a database schema, and a Web portal that will collect and filter available job monitoring information from various resources and present it to users in a user-centric view rather than and administrative-centric point of view.
Date: November 12, 2009
Creator: Alexander, David A.
Object Type: Report
System: The UNT Digital Library
HANFORD SITE LOW EXPOSURE PIPELINE REPAIR USING A NON-METALLIC COMPOSITE SYSTEM (open access)

HANFORD SITE LOW EXPOSURE PIPELINE REPAIR USING A NON-METALLIC COMPOSITE SYSTEM

At the Department of Energy, Richland Operations (DOE-RL) Hanford site in eastern Washington, a 350 mm (14 inch) diameter high density polyethylene (HDPE) pump recirculation pipeline failed at a bonded joint adjacent to a radiologically and chemically contaminated groundwater storage basin. The responsible DOE-RL contractor, CH2MHill Plateau Remediation Company, applied a fiberglass reinforced plastic (composite) field repair system to the failed joint. The system was devised specifically for the HDPE pipe repair at the Hanford site, and had not been used on this type of plastic piping previously. This paper introduces the pipe failure scenario, describes the options considered for repair and discusses the ultimate resolution of the problem. The failed pipeline was successfully returned to service with minimal impact on waste water treatment plant operating capacity. Additionally, radiological and chemical exposures to facility personnel were maintained as low as reasonably achievable (ALARA). The repair is considered a success for the near term, and future monitoring will prove whether the repair can be considered for long term service and as a viable alternative for similar piping failures at the Hanford site.
Date: November 12, 2009
Creator: Huth, R. J.
Object Type: Article
System: The UNT Digital Library
Heat of Combustion of Tantalum-Tungsten Oxide Thermite Composites (open access)

Heat of Combustion of Tantalum-Tungsten Oxide Thermite Composites

None
Date: November 12, 2009
Creator: Cervantes, O; Kuntz, J; Gash, A & Munir, Z
Object Type: Article
System: The UNT Digital Library
An Innovative Three-Dimensional Heterogeneous Coarse-Mesh Transport Method for Advanced and Generation IV Reactor Core Analysis and Design (open access)

An Innovative Three-Dimensional Heterogeneous Coarse-Mesh Transport Method for Advanced and Generation IV Reactor Core Analysis and Design

This project has resulted in a highly efficient method that has been shown to provide accurate solutions to a variety of 2D and 3D reactor problems. The goal of this project was to develop (1) an accurate and efficient three-dimensional whole-core neutronics method with the following features: based sollely on transport theory, does not require the use of cross-section homogenization, contains a highly accurate and self-consistent global flux reconstruction procedure, and is applicable to large, heterogeneous reactor models, and to (2) create new numerical benchmark problems for code cross-comparison.
Date: November 12, 2009
Creator: Rahnema, Farzad
Object Type: Report
System: The UNT Digital Library
Lithium Loaded Glass Fiber Neutron Detector Tests (open access)

Lithium Loaded Glass Fiber Neutron Detector Tests

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. Reported here are the results of tests of the lithium-loaded glass fibers option. This testing measured the neutron detection efficiency and gamma ray rejection capabilities of a small system manufactured by Nucsafe (Oak Ridge, TN).
Date: November 12, 2009
Creator: Ely, James H.; Erikson, Luke E.; Kouzes, Richard T.; Lintereur, Azaree T. & Stromswold, David C.
Object Type: Report
System: The UNT Digital Library
Recent Advances in VisIt: AMR Streamlines and Query-Driven Visualization (open access)

Recent Advances in VisIt: AMR Streamlines and Query-Driven Visualization

Adaptive Mesh Refinement (AMR) is a highly effective method for simulations spanning a large range of spatiotemporal scales such as those encountered in astrophysical simulations. Combining research in novel AMR visualization algorithms and basic infrastructure work, the Department of Energy's (DOEs) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) has extended VisIt, an open source visualization tool that can handle AMR data without converting it to alternate representations. This paper focuses on two recent advances in the development of VisIt. First, we have developed streamline computation methods that properly handle multi-domain data sets and utilize effectively multiple processors on parallel machines. Furthermore, we are working on streamline calculation methods that consider an AMR hierarchy and detect transitions from a lower resolution patch into a finer patch and improve interpolation at level boundaries. Second, we focus on visualization of large-scale particle data sets. By integrating the DOE Scientific Data Management (SDM) Center's FastBit indexing technology into VisIt, we are able to reduce particle counts effectively by thresholding and by loading only those particles from disk that satisfy the thresholding criteria. Furthermore, using FastBit it becomes possible to compute parallel coordinate views efficiently, thus facilitating interactive …
Date: November 12, 2009
Creator: Weber, Gunther; Ahern, Sean; Bethel, Wes; Borovikov, Sergey; Childs, Hank; Deines, Eduard et al.
Object Type: Article
System: The UNT Digital Library
REVIEW OF PLUTONIUM OXIDATION LITERATURE (open access)

REVIEW OF PLUTONIUM OXIDATION LITERATURE

A brief review of plutonium oxidation literature was conducted. The purpose of the review was to ascertain the effect of oxidation conditions on oxide morphology to support the design and operation of the PDCF direct metal oxidation (DMO) furnace. The interest in the review was due to a new furnace design that resulted in oxide characteristics that are different than those of the original furnace. Very little of the published literature is directly relevant to the DMO furnace operation, which makes assimilation of the literature data with operating conditions and data a convoluted task. The oxidation behavior can be distilled into three regimes, a low temperature regime (RT to 350 C) with a relatively slow oxidation rate that is influenced by moisture, a moderate temperature regime (350-450 C) that is temperature dependent and relies on more or less conventional oxidation growth of a partially protective oxide scale, and high temperature oxidation (> 500 C) where the metal autocatalytically combusts and oxidizes. The particle sizes obtained from these three regimes vary with the finest being from the lowest temperature. It is surmised that the slow growth rate permits significant stress levels to be achieved that help break up the oxides. The …
Date: November 12, 2009
Creator: Korinko, P.
Object Type: Report
System: The UNT Digital Library
Risk of Low Dose/Low Dose Rate Ionizing Radiation to Humans Symposium at the EMS 2009 Annual Meeting - September 2006 (open access)

Risk of Low Dose/Low Dose Rate Ionizing Radiation to Humans Symposium at the EMS 2009 Annual Meeting - September 2006

The low dose symposium thoughtfully addressed controversy of risk from low dose radiation exposure, hormesis and radon therapy. The stem cell symposium cogently considered the role of DNA damage and repair in hematopoietic stem cells underlying aging and malignancy and provocatively presented evidence that stem cells may have distinct morphologies and replicative properties, as well as special roles in cancer initiation. In the epigenetics symposium, studies illustrated the long range interaction of epigenetic mechanisms, the roles of CTCF and BORIS in region/specific regulation of epigenetic processes, the impact of DNA damage on epigenetic processes as well as links between epigenetic mechanisms and early nutrition and bystander effects.
Date: November 12, 2009
Creator: Morgan, William F.; von Borstel, Robert C.; Brenner, David; Redpath, J. Leslie; Erickson, Barbra E. & Brooks, Antone L.
Object Type: Article
System: The UNT Digital Library
Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials (open access)

Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials

The red, tetragonal form of lead oxide, alpha-PbO, litharge, and the yellow, orthorhombic form, beta-PbO, massicot, have been synthesized from lead(II) salts in aqueous media at elevated temperature. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the size, morphology, and crystallographic structural forms of the products. The role of impurities in the experimental synthesis of the materials and microstructural variations in the final products are described, and the implications of these observations with respect to the synthesis of different conducting lead oxides and other related materials are discussed.
Date: November 12, 2009
Creator: Perry, Dale L. & Wilkinson, T. J.
Object Type: Article
System: The UNT Digital Library
Challenges and opportunities in high-precision Be-10 measurements at CAMS (open access)

Challenges and opportunities in high-precision Be-10 measurements at CAMS

None
Date: October 12, 2009
Creator: Rood, D. H.; Hall, S.; Guilderson, T. P.; Finkel, R. C. & Brown, T. A.
Object Type: Article
System: The UNT Digital Library
Excited Spectator Electron Effects on Spectral Line Shapes (open access)

Excited Spectator Electron Effects on Spectral Line Shapes

Excited spectator electron effects on Stark broadened spectral line shapes of transitions involving tightly bound electrons are investigated. It is shown that the interference terms in the electron impact broadening are essential to describe the overlapping lines generated by these configurations (e.g.; dielectronic satellite lines). The main impact is narrower spectral features and reduced far wing intensities compared to calculations neglecting the interference terms.
Date: October 12, 2009
Creator: Iglesias, C A
Object Type: Article
System: The UNT Digital Library
High-Energy Physics Outstanding Junior Investigating Program (open access)

High-Energy Physics Outstanding Junior Investigating Program

Throughout the past five years I have worked to uncover what physics lies beyond that of the standard model. My main focus in the first two and a half years has been to understand physics at the electroweak scale, and to a lesser extent understand the relationship between particle physics and cosmology. My final two and a half years was spent on studying the feasibility of discovering “non-standard” models of electroweak physics at hadron colliders, working in close contact with experimentalists at the Tevatron and the LHC. My biggest successes during this period has been both in electroweak physics – expanding our understanding of the Higgs sector in supersymmetric theories and ultraviolet completions of little Higgs theories – and in collider physics – discovering a method for identifying high momentum top quarks and realizing the potential for LHCb to discover some versions of supersymmetry. I have also made some progress towards a particle physics/effective field theory solution of the cosmological constant problem.
Date: October 12, 2009
Creator: Kaplan, David, E.
Object Type: Report
System: The UNT Digital Library
Impacts of Standard 90.1-2007 for Commercial Buildings at State Level (open access)

Impacts of Standard 90.1-2007 for Commercial Buildings at State Level

This report examines the requirements of Standard 90.1-2007 on commercial buildings on a state-by-state basis with a separate, stand-alone chapter for each state. Standard 90.1-2007 is compared to the current state code for most states. This is the final version of the draft previously cleared and assigned ERICA # PNNL-18544, titled "Commercial Nationwide Report."
Date: October 12, 2009
Creator: Bartlett, Rosemarie; Halverson, Mark A. & Gowri, Krishnan
Object Type: Report
System: The UNT Digital Library
Letter of Intent to Build a MiniBooNE Near Detector:BooNE (open access)

Letter of Intent to Build a MiniBooNE Near Detector:BooNE

There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the {approx}1 eV{sup 2} scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrinos and which may be related to the LSND signal. No excess of electron-like events (-0.5 {+-} 7.8 {+-} 8.7), however, is observed so far at low energies in antineutrino mode. Furthermore, global 3+1 and 3+2 sterile neutrino fits to the world neutrino and antineutrino data suggest a difference between neutrinos and antineutrinos with significant (sin{sup 2} 2{theta}{sub {mu}{mu}} {approx} 35%) {bar {nu}}{sub {mu}} disappearance. In order to test whether the low-energy excess is due to neutrino oscillations and whether there is a difference between {nu}{sub {mu}} and {bar {nu}}{sub {mu}} disappearance, we propose building a second MiniBooNE detector at (or moving the existing MiniBooNE detector to) a distance of {approx}200 m from the Booster Neutrino Beam (BNB) production target. With identical detectors at different distances, most of the systematic errors will cancel when taking a ratio of events in the two detectors, as …
Date: October 12, 2009
Creator: Stancu, I.; Djurcic, Z.; Smith, D.; Ford, R.; Kobilarcik, T.; Marsh, W. et al.
Object Type: Report
System: The UNT Digital Library
Modeling Windows in Energy Plus with Simple Performance Indices (open access)

Modeling Windows in Energy Plus with Simple Performance Indices

The building energy simulation program, Energy Plus (E+), cannot use standard window performance indices (U, SHGC, VT) to model window energy impacts. Rather, E+ uses more accurate methods which require a physical description of the window. E+ needs to be able to accept U and SHGC indices as window descriptors because, often, these are all that is known about a window and because building codes, standards, and voluntary programs are developed using these terms. This paper outlines a procedure, developed for E+, which will allow it to use standard window performance indices to model window energy impacts. In this 'Block' model, a given U, SHGC, VT are mapped to the properties of a fictitious 'layer' in E+. For thermal conductance calculations, the 'Block' functions as a single solid layer. For solar optical calculations, the model begins by defining a solar transmittance (Ts) at normal incidence based on the SHGC. For properties at non-normal incidence angles, the 'Block' takes on the angular properties of multiple glazing layers; the number and type of layers defined by the U and SHGC. While this procedure is specific to E+, parts of it may have applicability to other window/building simulation programs.
Date: October 12, 2009
Creator: Arasteh, Dariush; Kohler, Christian & Griffith, Brent
Object Type: Report
System: The UNT Digital Library
Monitoring applications once they are in the user community (open access)

Monitoring applications once they are in the user community

Once an application is released into the user community, obtaining prompt and high quality information on application usage, applicability and reliability can be a challenge. Most Linux and Solaris applications used at RHIC and associated accelerators have been instrumented so that application and crash information is gathered, stored and forwarded to the appropriate developer for immediate analysis. To support this process, databases were created to track developer and application information. In order to keep these databases relevant, a web based application release procedure was created to collect information and automatically update the database. Additional capabilities have been developed that utilize and expand on the various components of this system to promote communication between developers and users, and to monitor applications. An application feedback feature allows users to instantly communicate with application developers. An application history system records application usage and reliability.
Date: October 12, 2009
Creator: Binello, S.
Object Type: Article
System: The UNT Digital Library
On-demand Overlay Networks for Large Scientific Data Transfers (open access)

On-demand Overlay Networks for Large Scientific Data Transfers

Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.
Date: October 12, 2009
Creator: Ramakrishnan, Lavanya; Guok, Chin; Jackson, Keith; Kissel, Ezra; Swany, D. Martin & Agarwal, Deborah
Object Type: Article
System: The UNT Digital Library
Proteomic Profiling of Mesenchymal Stem Cell Responses to Mechanical Strain and TGF-B1 (open access)

Proteomic Profiling of Mesenchymal Stem Cell Responses to Mechanical Strain and TGF-B1

Mesenchymal stem cells (MSCs) are a potential source of smooth muscle cells (SMCs) for constructing tissue-engineered vascular grafts. However, the details of how specific combinations of vascular microenvironmental factors regulate MSCs are not well understood. Previous studies have suggested that both mechanical stimulation with uniaxial cyclic strain and chemical stimulation with transforming growth factor {beta}1 (TGF-{beta}1) can induce smooth muscle markers in MSCs. In this study, we investigated the combined effects of uniaxial cyclic strain and TGF-{beta}1 stimulation on MSCs. By using a proteomic analysis, we found differential regulation of several proteins and genes, such as the up-regulation of TGF-{beta}1-induced protein ig-h3 (BGH3) protein levels by TGF-{beta}1 and up-regulation of calponin 3 protein level by cyclic strain. At the gene expression level, BGH3 was induced by TGF-{beta}1, but calponin 3 was not significantly regulated by mechanical strain or TGF-{beta}1, which was in contrast to the synergistic up-regulation of calponin 1 gene expression by cyclic strain and TGF-{beta}1. Further experiments with cycloheximide treatment suggested that the up-regulation of calponin 3 by cyclic strain was at post-transcriptional level. The results in this study suggest that both mechanical stimulation and TGF-{beta}1 signaling play unique and important roles in the regulation of MSCs at …
Date: October 12, 2009
Creator: Kurpinski, Kyle; Chu, Julia; Wang, Daojing & Li, Song
Object Type: Report
System: The UNT Digital Library
Quantification of Absorption, Retention and Elimination of Two Different Oral Doses of Vitamin a in Zambian Boys Using Accelerator Mass Spectrometry (open access)

Quantification of Absorption, Retention and Elimination of Two Different Oral Doses of Vitamin a in Zambian Boys Using Accelerator Mass Spectrometry

A recent survey indicated that high-dose vitamin A supplements (HD-VAS) had no apparent effect on vitamin A (VA) status of Zambian children <5 y of age. To explore possible reasons for the lack of response to HD-VAS among Zambian children, we quantified the absorption, retention, and urinary elimination of either a single HDVAS (60 mg) or a smaller dose of stable isotope (SI)-labeled VA (5 mg), which was used to estimate VA pool size, in 3-4 y old Zambian boys (n = 4 for each VA dose). A 25 nCi tracer dose of [{sup 14}C{sub 2}]-labeled VA was co-administered with the HD-VAS or SI-labeled VA, and 24-hr stool and urine samples were collected for 3 and 7 consecutive days, respectively, and 24-hr urine samples at 4 later time points. Accelerator Mass Spectrometry (AMS) was used to measure the cumulative excretion of {sup 14}C in stool and urine 3d after dosing to estimate, respectively, absorption and retention of the VAS and SI-labeled VA. The urinary elimination rate (UER) was estimated by plotting {sup 14}C in urine vs. time, and fitting an exponential equation to the data. Estimates of mean absorption, retention and the UER were 83.8 {+-} 7.1%, 76.3 {+-} 6.7%, …
Date: October 12, 2009
Creator: Aklamati, E. K.; Mulenga, M.; Dueker, S. R.; Buchholz, B. A.; Peerson, J. M.; Kafwembe, E. et al.
Object Type: Article
System: The UNT Digital Library
Thermal Wadis in Support of Lunar Exploration: Concept Development and Utilization (open access)

Thermal Wadis in Support of Lunar Exploration: Concept Development and Utilization

Thermal wadis, engineered sources of heat, can be used to extend the life of lunar rovers by keeping them warm during the extreme cold of the lunar night. Thermal wadis can be manufactured by sintering or melting lunar regolith into a solid mass with more than two orders of magnitude higher thermal diffusivities compared to native regolith dust. Small simulant samples were sintered and melted in the electrical furnaces at different temperatures, different heating and cooling rates, various soaking times, under air, or in an argon atmosphere. The samples were analyzed with scanning electron microscopy and energy dispersive spectroscopy, X-ray diffraction, a laser-flash thermal diffusivity system, and the millimeter-wave system. The melting temperature of JSC-1AF simulant was ~50°C lower in an Ar atmosphere compared to an air atmosphere. The flow of Ar during sintering and melting resulted in a small mass loss of 0.04 to 0.1 wt% because of the volatization of alkali compounds. In contrast, the samples that were heat-treated under an air atmosphere gained from 0.012 to 0.31 wt% of the total weight. A significantly higher number of cavities were formed inside the samples melted under an argon atmosphere, possibly because of the evolution of oxygen bubbles from …
Date: October 12, 2009
Creator: Matyas, Josef; Wegeng, Robert S. & Burgess, Jeremy M.
Object Type: Report
System: The UNT Digital Library
Trials, tribulations, and pitfalls using commercial instruments for data acquisition (open access)

Trials, tribulations, and pitfalls using commercial instruments for data acquisition

Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) uses many commercially available instruments - for example spectrum analyzers, oscilloscopes, digital volt meters, signal generators - as integral parts of instrumentation and control systems. Typically these systems are remotely controlled. Using commercial instruments has many benefits. Manufactures have the skill, knowledge, and experience to produce high quality products. The price performance ratio is hard to duplicate. There are also disadvantages. Proprietary interfaces, single platform drivers, and reliable operation provide challenges for implementation and unattended operation. Several of the systems used at RHIC will be described. Their issues and solutions will be presented.
Date: October 12, 2009
Creator: Lee,R.C.; Olsen, R. H. & Unger, K. L.
Object Type: Article
System: The UNT Digital Library