Measurement of actinide neutron cross sections (open access)

Measurement of actinide neutron cross sections

The maintenance of strong scientific expertise is criticalto the U.S. nuclear attribution community. It is particularly importantto train students in actinide chemistry and physics. Neutroncross-section data are vital components to strategies for detectingexplosives and fissile materials, and these measurements requireexpertise in chemical separations, actinide target preparation, nuclearspectroscopy, and analytical chemistry. At the University of California,Berkeley and the Lawrence Berkeley National Laboratory we have trainedstudents in actinide chemistry for many years. LBNL is a leader innuclear data and has published the Table of Isotopes for over 60 years.Recently, LBNL led an international collaboration to measure thermalneutron capture radiative cross sections and prepared the EvaluatedGamma-ray Activation File (EGAF) in collaboration with the IAEA. Thisfile of 35,000 prompt and delayed gamma ray cross-sections for allelements from Z=1-92 is essential for the neutron interrogation ofnuclear materials. LBNL has also developed new, high flux neutrongenerators and recently opened a 1010 n/s D+D neutron generatorexperimental facility.
Date: June 15, 2003
Creator: Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL. & English, Gerald
Object Type: Report
System: The UNT Digital Library
Cryogenic refrigeration requirements for superconducting insertion devices in a light source (open access)

Cryogenic refrigeration requirements for superconducting insertion devices in a light source

This report discusses cryogenic cooling superconducting insertion devices for modern light sources. The introductory part of the report discusses the difference between wiggler and undulators and how the bore temperature may affect the performance of the magnets. The steps one would take to reduce the gap between the cold magnet pole are discussed. One section of the report is devoted to showing how one would calculate the heat that enters the device. Source of heat include, heat entering through the vacuum chamber, heating due to stray electrons and synchrotron radiation, heating due to image current on the bore, heat flow by conduction and radiation, and heat transfer into the cryostat through the magnet leads. A section of he report is devoted to cooling option such as small cryo-cooler and larger conventional helium refrigerators. This section contains a discussion as to when it is appropriate to use small coolers that do not have J-T circuits. Candidates small cryo-coolers are discussed in this section of the report. Cooling circuits for cooling with a conventional refrigerator are also discussed. A section of the report is devoted to vibration isolation and how this may affect how the cooling is attached to the device. Vibration …
Date: August 15, 2003
Creator: Green, Michael A.; Green, Michael A. & Green, Michael A.
Object Type: Report
System: The UNT Digital Library
Probing Interactions at the Nanoscale: Sensing Protein Molecules (open access)

Probing Interactions at the Nanoscale: Sensing Protein Molecules

Introduction We have developed a high-frequency electronic biosensor of parallel-plate geometry that is embedded within a microfluidic device. This novel biosensor allows us to perform dielectric spectroscopy on a variety of biological samples—from cells to molecules—in solution. Because it is purely electronic, the sensor allows for rapid characterization with no sample preparation or chemical alteration. In addition, it is capable of probing length scales from millimeters to microns over a frequency range 50 MHz to 40 GHz, and sample volumes as small as picoliters [1,2]. Our high-frequency biosensor has evolved from previous device designs based on a coplanar waveguide (CPW) geometry [2]. For our current device, we employ microfluidic tectonics (µFT) [3] to embed two microstrip conductors within a microfluidic channel. The electronic coupling between the two conductors is greater than in our previous CPW design and more importantly, leads to an enhanced sensitivity. Our utilization of µFT allows us to incorporate easily this high-frequency electronic biosensor with a variety of lab-on-a-chip architectures. Device Description Figure 1 is a schematic of our high-frequency electronic biosensor. We fabricate this sensor by first depositing a 500 Å seed layer of gold onto two glass microscope slides. We then use photolithography to pattern …
Date: September 15, 2003
Creator: Sohn, Lydia; Weiss, Ron & Tavazoie, Saeed
Object Type: Report
System: The UNT Digital Library
Cryogenic refrigeration requirements for superconducting insertion devices in a light source (open access)

Cryogenic refrigeration requirements for superconducting insertion devices in a light source

This report discusses cryogenic cooling superconducting insertion devices for modern light sources. The introductory part of the report discusses the difference between wiggler and undulators and how the bore temperature may affect the performance of the magnets. The steps one would take to reduce the gap between the cold magnet pole are discussed. One section of the report is devoted to showing how one would calculate the heat that enters the device. Source of heat include, heat entering through the vacuum chamber, heating due to stray electrons and synchrotron radiation, heating due to image current on the bore, heat flow by conduction and radiation, and heat transfer into the cryostat through the magnet leads. A section of the report is devoted to cooling options such as small cryo-cooler and larger conventional helium refrigerators. This section contains a discussion as to when it is appropriate to use small coolers that do not have J-T circuits. Candidate small cryo-coolers are discussed in this section of the report. Cooling circuits for cooling with a conventional refrigerator are also discussed. A section of the report is devoted to vibration isolation and how this may affect how the cooling is attached to the device. Vibration …
Date: August 15, 2003
Creator: Green, Michael A.
Object Type: Report
System: The UNT Digital Library
Direct to Digital Holography (open access)

Direct to Digital Holography

In this CRADA, Oak Ridge National Laboratory (ORNL) assisted nLine Corporation of Austin, TX in the development of prototype semiconductor wafer inspection tools based on the direct-to-digital holographic (DDH) techniques invented at ORNL. Key components of this work included, development of the first prototype named the Visible Alpha Tool (VAT) that uses visible spectrum illumination of 532 nm, assist in design of second prototype tool named the DUV Alpha Tool (DAT) using deep UV (266 nm) illumination, and continuing support of nLine in the development of higher throughput commercial tools.
Date: June 15, 2003
Creator: Bingham, P.R. & Tobin, K.W.
Object Type: Report
System: The UNT Digital Library
Flow Instabilities During Injection of CO2 into SalineAquifers (open access)

Flow Instabilities During Injection of CO2 into SalineAquifers

Injection of carbon dioxide (CO{sub 2}) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO{sub 2}) the viscosity of carbon dioxide can be less than the viscosity of the aqueous phase by a factor of 15. Because of the lower viscosity, the CO{sub 2} displacement front will have a tendency towards instability so that waves or rounded lobes of saturation may appear and grow into fingers that lead to enhanced dissolution, bypassing, and possibly poor sweep efficiency. This paper presents an analysis, through high-resolution numerical simulations, of the onset of instabilities (viscous fingering) during injection of CO{sub 2} into saline aquifers. We explore the influence of viscosity ratio, relative permeability functions, and capillary pressure on finger growth and spacing. In addition, we address the issues of finger triggering, convergence under grid refinement and boundary condition effects. Simulations were carried out on scalar machines, and on an IBM RS/6000 SP (a distributed-memory parallel computer with 6080 processors) with a parallelized version of TOUGH2.
Date: April 15, 2003
Creator: Garcia, Julio E. & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Engine Control Improvement through Application of Chaotic Time Series Analysis (open access)

Engine Control Improvement through Application of Chaotic Time Series Analysis

The objective of this program was to investigate cyclic variations in spark-ignition (SI) engines under lean fueling conditions and to develop options to reduce emissions of nitrogen oxides (NOx) and particulate matter (PM) in compression-ignition direct-injection (CIDI) engines at high exhaust gas recirculation (EGR) rates. The CIDI activity builds upon an earlier collaboration between ORNL and Ford examining combustion instabilities in SI engines. Under the original CRADA, the principal objective was to understand the fundamental causes of combustion instability in spark-ignition engines operating with lean fueling. The results of this earlier activity demonstrated that such combustion instabilities are dominated by the effects of residual gas remaining in each cylinder from one cycle to the next. A very simple, low-order model was developed that explained the observed combustion instability as a noisy nonlinear dynamical process. The model concept lead to development of a real-time control strategy that could be employed to significantly reduce cyclic variations in real engines using existing sensors and engine control systems. This collaboration led to the issuance of a joint patent for spark-ignition engine control. After a few years, the CRADA was modified to focus more on EGR and CIDI engines. The modified CRADA examined relationships between …
Date: July 15, 2003
Creator: Green, J.B., Jr. & Daw, C.S.
Object Type: Report
System: The UNT Digital Library
Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) (open access)

Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994)

We used a climate-driven regression model to develop spatially resolved estimates of soil-CO{sub 2} emissions from the terrestrial land surface for each month from January 1980 to December 1994, to evaluate the effects of interannual variations in climate on global soil-to-atmosphere CO{sub 2} fluxes. The mean annual global soil-CO{sub 2} flux over this 15-y period was estimated to be 80.4 (range 79.3-81.8) Pg C. Monthly variations in global soil-CO{sub 2} emissions followed closely the mean temperature cycle of the Northern Hemisphere. Globally, soil-CO{sub 2} emissions reached their minima in February and peaked in July and August. Tropical and subtropical evergreen broad-leaved forests contributed more soil-derived CO{sub 2} to the atmosphere than did any other vegetation type ({approx}30% of the total) and exhibited a biannual cycle in their emissions. Soil-CO{sub 2} emissions in other biomes exhibited a single annual cycle that paralleled the seasonal temperature cycle. Interannual variability in estimated global soil-CO{sub 2} production is substantially less than is variability in net carbon uptake by plants (i.e., net primary productivity). Thus, soils appear to buffer atmospheric CO{sub 2} concentrations against far more dramatic seasonal and interannual differences in plant growth. Within seasonally dry biomes (savannas, bushlands, and deserts), interannual variability in …
Date: September 15, 2003
Creator: Raich, J.W.
Object Type: Report
System: The UNT Digital Library
Linking reaction, transport, and hydrological parameters inunsaturated fractured rock: toughreact implementation andapplication (open access)

Linking reaction, transport, and hydrological parameters inunsaturated fractured rock: toughreact implementation andapplication

Modeling coupled water-gas-rock interactions in unsaturated fractured rock requires conceptual and numerical model considerations beyond those developed for saturated porous media. This paper focuses on the integration of the geological and hydrological parameters into the calculation of reactive-transport parameters and the feedback of mineral precipitation/dissolution to flow and transport. These basic relations have been implemented in the reactive transport code TOUGHREACT (Xu et al., 2003) that couples equilibrium and kinetic water-gas-rock inter-actions with multiphase flow and aqueous and gaseous species transport. Simulation results are presented illustrating the effects of water-rock interaction accompanying the heating of unsaturated heterogeneous fractured tuff. Unknowns associated with modeling water-rock interaction in fractured unsaturated systems are the area of the fracture surface that is wetted and which fractures are active components of the overall flow system. The wetted fracture area is important not only to water-rock interaction but to flow and transport between fluids flowing in fractures and the adjacent matrix. The other unknown relations are those describing permeability and capillary pressure modification during mineral precipitation and dissolution. Here we discuss solely the relations developed for fractures and the fracture-matrix interface.
Date: May 15, 2003
Creator: Sonnenthal, Eric; Spycher, Nicolas & Xu, Tianfu
Object Type: Article
System: The UNT Digital Library
PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP: THEORY STUDIES FOR POLARIZED PP SCATTERING (VOLUME 53) (open access)

PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP: THEORY STUDIES FOR POLARIZED PP SCATTERING (VOLUME 53)

In the past two runs of RHIC, the first measurements with polarized proton beams have been performed. For many years to come, the RHIC spin program will offer exciting physics, exploring QCD and the nucleon in new ways. The aim of this small workshop was to attract several spin theorists to the center for about two weeks, in order to collaborate with both experimentalists and theorists at RBRC, and to initiate and/or complete studies of relevance to RHIC spin. A major focus of polarized-pp measurements at RHIC is on measuring the spin-dependent gluon density, {Delta}g. A channel for accessing {Delta}g is high-p{sub T} pion production. The unpolarized cross section for this reaction has been measured by PHENIX and was found in good agreement with a perturbative-QCD based (NLO) calculation. It was a remarkable and exciting coincidence that PHENIX presented also the first results for the spin asymmetry for {rvec p}{rvec p} {yields} {pi}{sup 0}X during this workshop. This sparked a lot of additional activity and discussion. First steps toward the interpretation of the data were taken. Marco Stratmann and Barbara Jager (Regensburg University) presented recent work on the NLO calculation of the polarized cross section and the spin asymmetry, setting …
Date: September 15, 2003
Creator: KRETZER,S. VOGELSANG,W.
Object Type: Report
System: The UNT Digital Library
Environmentally Benign Stab Detonators (open access)

Environmentally Benign Stab Detonators

This effort attempts to demonstrate that environmentally acceptable energetic sol-gel coated flash metal multilayer nanocomposites can be used to replace current impact initiated devices (IIDs) which have hazardous and toxic components. Successful completion of this project will result in IIDs that include innocuous compounds, have sufficient output energy for initiation, meet current military specifications, are small, cost competitive, and perform as well as or better than current devices. We expect flash metal multilayer and sol-gel to be generic technologies applicable to a wide range of devices, especially in small caliber ammunition and sub-munitions. We will replace the NOL-130 mixture with a nanocomposite that consists of a mechanically robust energetic multilayer foil that has been coated with a sol-gel energetic material. The exothermic reactions are activated in this nanocomposite are the transformation of the multilayer material to its respective intermetallic alloy and the thermite reaction, which is characterized by very high temperatures, a small pressure pulse, and hot particle ejection. The proposed materials and their reaction products consist of, but are not limited to aluminum, nickel, iron, aluminum oxide, titanium, iron oxide and boron. These materials have much more desirable environmental and health characteristics than the NOL-130 composition.
Date: December 15, 2003
Creator: Gash, A.; Barbee, T.; Simpson, R.; Satcher, J. & Walton, C.
Object Type: Report
System: The UNT Digital Library
Investigation of Main-Chamber and Divertor Recycling in DIII-D Using Tangentially Viewing CID Cameras (open access)

Investigation of Main-Chamber and Divertor Recycling in DIII-D Using Tangentially Viewing CID Cameras

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Date: July 15, 2003
Creator: Groth, M.; Porter, G. D.; Petrie, T. W.; Fenstermacher, M. E. & Brooks, N. H.
Object Type: Article
System: The UNT Digital Library
Retrieval and Pipeline Transfer Assessment of Hanford Tank 241-AN-105 Waste (open access)

Retrieval and Pipeline Transfer Assessment of Hanford Tank 241-AN-105 Waste

This study assesses five steps for Tank 241-AN-105 waste retrieval and subsequent pipeline transfer: 1. Remove supernatant liquid waste from AN-105 and transfer it through a pipeline with inline dilution with water (1st liquid waste transfer). 2. Add water (as a diluent) to Tank AN-105. 3. Mix the saltcake waste and water with mixer pumps to dissolve soluble solids. 4. Let undissolved solids settle to the tank bottom. 5. Remove the resulting supernatant liquid waste from Tank AN-105 (2nd liquid waste transfer). To assess these five steps for waste retrieval and pipeline transfer, AN-105 waste rheology was measured and solids identified with bright field image, select area diffraction, and energy dispersive x-ray spectroscopy. By combining available in situ and laboratory data, an AN-105 specific viscosity model was developed that can change from several centiPoise of viscosity to tens of millions of centiPoise as a function of strain rate and solid concentration. This viscosity mo del was implemented into the AN-105 computer model to simulate pump jet mixing. The report also evaluates AN-105 slurry waste transfer to AP-102 and AP-104 through a 3-inch (0.07-m) pipeline.
Date: January 15, 2003
Creator: Onishi, Yasuo; Tingey, Joel M.; Recknagle, Kurtis P.; Liu, Jun; Terrones, Guillermo; Yokuda, Satoru T. et al.
Object Type: Report
System: The UNT Digital Library
Quarterly Report (Reporting Period January 15, 2003 through April 15, 2003) (open access)

Quarterly Report (Reporting Period January 15, 2003 through April 15, 2003)

Summaries of the activities and accomplishments during this second quarter reporting period for each of the consortium participants are given. Some of the highlights for this reporting period include: Even without the forcing speaker, the ''Mozart'' device on the GCM geometry provides over 20% reduction in drag at 0 degree yaw and above 25% reductions at higher yaw angles; Experiments and computations guide a conceptual design for reduction of drag due to tractor-trailer gap flow; RANS simulations for the GTS geometry are being finalized for development of clear modeling guidelines with RANS; Simulations on the GCM geometry have begun; and Vortex methods have improved techniques for the treatment of vorticity near surfaces.
Date: May 15, 2003
Creator: McCallen, R.; Salari, K.; Ortega, J.; Browand, F.; Hammache, M.; Hsu, T. Y. et al.
Object Type: Report
System: The UNT Digital Library
DISPLACEMENT BASED SEISMIC DESIGN METHODS. (open access)

DISPLACEMENT BASED SEISMIC DESIGN METHODS.

A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research …
Date: July 15, 2003
Creator: Hofmayer, C.; Miller, C.; Hwang, Y. & Costello, J.
Object Type: Article
System: The UNT Digital Library
DESIGN OF SUPERCONDUCTING COMBINED FUNCTION MAGNETS FOR THE 50 GEV PROTON BEAM LINE FOR THE J-PARC NEUTRINO EXPERIMENT. (open access)

DESIGN OF SUPERCONDUCTING COMBINED FUNCTION MAGNETS FOR THE 50 GEV PROTON BEAM LINE FOR THE J-PARC NEUTRINO EXPERIMENT.

Superconducting combined function magnets will be utilized for the 50GeV-750kW proton beam line for the J-PARC neutrino experiment and an R and D program has been launched at KEK. The magnet is designed to provide a combined function with a dipole field of 2.59 T and a quadrupole field of 18.7 T/m in a coil aperture of 173.4 mm. A single layer coil is proposed to reduce the fabrication cost and the coil arrangement in the 2-D cross-section results in left-right asymmetry. This paper reports the design study of the magnet.
Date: June 15, 2003
Creator: Wanderer, P. & Al., Et
Object Type: Article
System: The UNT Digital Library
C-200 Series Tanks Vacuum Retrieval System Aerosol Test Results (open access)

C-200 Series Tanks Vacuum Retrieval System Aerosol Test Results

The radioactive wastes stored in tanks 241-C-201, 241-C-202, 241-C-203, and 241-C-204 (the C-200 series tanks) are to be retrieved with the C-200 vacuum retrieval system (VRS). The VRS will suck the waste up through an articulated mast system, separate it from the suspending air, collect and transfer it to a receiver batch tank, and return the air as exhaust to the waste tank being retrieved. An analysis of potential accidents has indicated that a break in the line used to return the exhaust to the waste tank could release unacceptable quantities of suspended radioactive material to the environment. To estimate the quantity of suspended material and determine accident risks, CH2M HILL and Pacific Northwest National Laboratory (PNNL) conducted tests with the VRS using nonradioactive waste simulants at the Hanford Cold Test Facility. This report describes the tests conducted and presents and discusses the results.
Date: September 15, 2003
Creator: Huckaby, James L.; Glissmeyer, John A. & Gray, Paul E.
Object Type: Report
System: The UNT Digital Library
Measured and Calculated Losses in a Model Dipole for Gsi's Heavy Ion Synchrotron. (open access)

Measured and Calculated Losses in a Model Dipole for Gsi's Heavy Ion Synchrotron.

The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 300T{center_dot}m and 10OT{center_dot}m. Fast ramp times are needed. These can cause problems of ac loss and field distortion in the magnets. For the high energy ring, a lm model dipole magnet has been built, based on the RHIC dipole design. This magnet was tested under boiling liquid helium in a vertical dewar. The quench current showed very little dependence on ramp rate. The ac losses, measured by an electrical method, were fitted to straight line plots of loss/cycle versus ramp rate, thereby separating the eddy current and hysteresis components. These results were compared with calculated values, using parameters which had previously been measured on short samples of cable. Reasonably good agreement between theory and experiment was found, although the measured hysteresis loss is higher than expected in ramps to the highest field levels.
Date: June 15, 2003
Creator: Wanderer, P.; Anerella, M.; Ganetis, G.; Ghosh, A. K.; Joshi, P.; Marone, A. et al.
Object Type: Article
System: The UNT Digital Library
Developing Smart Seismic Arrays: A Simulation Environment, Observational Database, and Advanced Signal Processing (open access)

Developing Smart Seismic Arrays: A Simulation Environment, Observational Database, and Advanced Signal Processing

Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to be effectively utilized in the applications of seismic imaging and vehicle tracking where rapid (minutes to hours) and real-time analysis is required. The goal of this project is to build capabilities in acquisition system design, utilization and in full 3D finite difference modeling as well as statistical characterization of geological heterogeneity. Such capabilities coupled with a rapid field analysis methodology based on matched field processing are applied to problems associated with surveillance, battlefield management, finding hard and deeply buried targets, and portal monitoring. This project benefits the U.S. military and intelligence community in support of LLNL's national-security mission. FY03 was the final year of this project. In the 2.5 years this project has been active, numerous and varied developments and milestones have been accomplished. A wireless communication module for seismic data was developed to facilitate rapid seismic data acquisition and …
Date: September 15, 2003
Creator: Harben, P E; Harris, D; Myers, S; Larsen, S; Wagoner, J; Trebes, J et al.
Object Type: Report
System: The UNT Digital Library
Associated Higgs Boson Production With Heavy Quarks. (open access)

Associated Higgs Boson Production With Heavy Quarks.

The production of a Higgs boson in association with a pair of e quarks will play a very important role at both hadron and lepton colliders. We review the status of theoretical predictions and their relevance to Higgs boson studies, with particular emphasis on the recently calculated NLO QCD corrections to the inclusive cross section for p{bar p}, pp {yields} t{bar t}h. We conclude by briefly discussing the case of exclusive b{bar b}h production and the potential of this process in revealing signals of new physics beyond the Standard Model.
Date: March 15, 2003
Creator: Dawson, S.; Orr, L. H.; Reina, L. & Wackeroth, D.
Object Type: Article
System: The UNT Digital Library
Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes (open access)

Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host …
Date: November 15, 2003
Creator: Croff, A. G.; Lomenick, T. F.; Lowrie, R. S. & Stow, S. H.
Object Type: Report
System: The UNT Digital Library
PLEIADES: High Peak Brightness, Subpicosecond Thomson Hard-X-ray source (open access)

PLEIADES: High Peak Brightness, Subpicosecond Thomson Hard-X-ray source

The Picosecond Laser-Electron Inter-Action for the Dynamic Evaluation of Structures (PLEIADES) facility, is a unique, novel, tunable (10-200 keV), ultrafast (ps-fs), hard x-ray source that greatly extends the parameter range reached by existing 3rd generation sources, both in terms of x-ray energy range, pulse duration, and peak brightness at high energies. First light was observed at 70 keV early in 2003, and the experimental data agrees with 3D codes developed at LLNL. The x-rays are generated by the interaction of a 50 fs Fourier-transform-limited laser pulse produced by the TW-class FALCON CPA laser and a highly focused, relativistic (20-100 MeV), high brightness (1 nC, 0.3-5 ps, 5 mm.mrad, 0.2% energy spread) photo-electron bunch. The resulting x-ray brightness is expected to exceed 10{sup 20} ph/mm{sup 2}/s/mrad{sup 2}/0.1% BW. The beam is well-collimated (10 mrad divergence over the full spectrum, 1 mrad for a single color), and the source is a unique tool for time-resolved dynamic measurements in matter, including high-Z materials.
Date: December 15, 2003
Creator: Kuba, J.; Anderson, S. G.; Barty, C. J.; Betts, S. M.; Booth, R.; Brown, W. J. et al.
Object Type: Article
System: The UNT Digital Library
Annual Report for Environmental Management Science Program Project Number 86598 Coupled Flow and Reactivity in Variably Saturated Porous Media (open access)

Annual Report for Environmental Management Science Program Project Number 86598 Coupled Flow and Reactivity in Variably Saturated Porous Media

Improved models of contaminant migration in heterogeneous, variably saturated porous media are required to better define the long-term stewardship requirements for U.S. Department of Energy (DOE) lands and to assist in the design of effective vadose-zone barriers to contaminant migrations. The objective of our three-year project is to meet the DOE need by developing new experimental approaches to describe adsorption and transport of contaminants in heterogeneous, variably saturated media (i.e., the vadose zone). The research specifically addresses the behavior of strontium, a high priority DOE contaminant. However, the key benefit of this research is improved conceptual models of how all contaminants migrate through heterogeneous, variably-saturated, porous media. Research activities are driven by the hypothesis that the reactivity of variably saturated porous media is dependent on the moisture content of the medium and can be represented by a relatively simple function applicable over a range of scales, contaminants, and media. A key and novel aspect of our research is the use of the 2-meter radius geocentrifuge capabilities at the Idaho National Laboratory (INL) to conduct unsaturated reactive transport experiments (Figure 1). The experimental approach using the geocentrifuge provides data in a much shorter time period than conventional methods allowing us to …
Date: June 15, 2003
Creator: Palmer, Carl D.; Mattson, Earl D. & Smith, Robert W.
Object Type: Report
System: The UNT Digital Library
Experience with ActiveX control for simple channel access (open access)

Experience with ActiveX control for simple channel access

Accelerator control system applications at Berkeley Lab's Advanced Light Source (ALS) are typically deployed on operator consoles running Microsoft Windows 2000 and utilize EPICS[2]channel access for data access. In an effort to accommodate the wide variety of Windows based development tools and developers with little experience in network programming, ActiveX controls have been deployed on the operator stations. Use of ActiveX controls for use in the accelerator control environment has been presented previously[1]. Here we report on some of our experiences with the use and development of these controls.
Date: May 15, 2003
Creator: Timossi, C.; Nishimura, H. & McDonald, J.
Object Type: Article
System: The UNT Digital Library