SLAB symmetric dielectric micron scale structures for high gradient electron acceleration. (open access)

SLAB symmetric dielectric micron scale structures for high gradient electron acceleration.

A class of planar microstructure is proposed which provide high accelerating gradients when excited by an infrared laser pulse. These structures consist of parallel dielectric slabs separated by a vacuum gap; the dielectric or the outer surface coating are spatially modulated at the laser wavelength along the beam direction so as to support a standing wave accelerating field. We have developed numerical and analytic models of the accelerating mode fields in the structure. We show an optimized coupling scheme such that this mode is excited resonantly with a large quality factor. The status of planned experiments on fabricating and measuring these planar structures will be described.
Date: June 12, 1999
Creator: Rosenzweig, J. B. & Schoessow, P. V.
Object Type: Article
System: The UNT Digital Library
Computational model of drilling with high radiance pulsed lasers. Revision 1 (open access)

Computational model of drilling with high radiance pulsed lasers. Revision 1

A model of drilling by high radiance pulsed lasers is described. The model involves a one-dimensional description of heat transport below the bottom of the hole, hydrodynamic expansion of the vapor and compressed air, and light propagation through the vapor. The pressure and energy of the vapor are taken from a separate Saha equilibrium code. The boundary conditions at the vaporization surface include the formation of a transition layer within which macroscopic fluid conditions axe reached. The absorption mechanisms are photoionization and inverse bremsstrahlung. The model has been applied to the case of drilling in stainless steel with green copper laser light, for peak input intensities ranging from 10{sup 8} to 4 {times} 10{sup 10} W/cm{sup 2}. Below 3 {times} 10{sup 8} W/cm{sup 2}, there is negligible absorption in the vapor and ablation increases rapidly with intensity. After decreasing for a short interval beyond this point, the ablation rate then increases steadily with power because of a growing electron thermal conduction to the surface. The experimental ablation rate exhibits a somewhat faster overall growth. It appears comparable to the model at low power but is about five times greater at the highest power.
Date: October 12, 1994
Creator: Boley, C. D. & Early, J. T.
Object Type: Article
System: The UNT Digital Library
Radiation Transport Calculations on Unstructured Grids Using a Spatially Decomposed and Threaded Algorithm (open access)

Radiation Transport Calculations on Unstructured Grids Using a Spatially Decomposed and Threaded Algorithm

We consider the solution of time-dependent, energy-dependent, discrete ordinates, and nonlinear radiative transfer problems on three-dimensional unstructured spatial grids. We discuss the solution of this class of transport problems, using the code TETON, on large distributed-memory multinode computers having multiple processors per ''node'' (e.g. the IBM-SP). We discuss the use of both spatial decomposition using message passing between ''nodes'' and a threading algorithm in angle on each ''node''. We present timing studies to show how this algorithm scales to hundreds and thousands of processors. We also present an energy group ''batching'' algorithm that greatly enhances cache performance. Our conclusion, after considering cache performance, storage limitations and dependencies inherent in the physics, is that a model that uses a combination of message-passing and threading is superior to one that uses message-passing alone. We present numerical evidence to support our conclusion.
Date: April 12, 1999
Creator: Nemanic, M K & Nowak, P
Object Type: Article
System: The UNT Digital Library
An evaluation of the management system verification pilot at Hanford (open access)

An evaluation of the management system verification pilot at Hanford

The Chemical Management System (CMS), currently under development at Hanford, was used as the ''test program'' for pilot testing the value added aspects of the Chemical Manufacturers Association's (CMA) Management Systems Verification (MSV) process. The MSV process, which was developed by CMA's member chemical companies specifically as a tool to assist in the continuous improvement of environment, safety and health (ESH) performance, represents a commercial sector ''best practice'' for evaluating ESH management systems. The primary purpose of Hanford's MSV Pilot was to evaluate the applicability and utility of the MSV process in the Department of Energy (DOE) environment. However, because the Integrated Safety Management System (ISMS) is the framework for ESH management at Hanford and at all DOE sites, the pilot specifically considered the MSV process in the context of a possible future adjunct to Integrated Safety Management System Verification (ISMSV) efforts at Hanford and elsewhere within the DOE complex. The pilot involved the conduct of two-hour interviews with four separate panels of individuals with functional responsibilities related to the CMS including the Department of Energy Richland Operations (DOE-RL), Fluor Daniel Hanford (FDH) and FDH's major subcontractors (MSCS). A semi-structured interview process was employed by the team of three ''verifiers'' …
Date: November 12, 1998
Creator: BRIGGS, C.R.
Object Type: Report
System: The UNT Digital Library
Hanford site emergency response needs - Volume 3 (open access)

Hanford site emergency response needs - Volume 3

None
Date: December 12, 1996
Creator: Good, D.E.
Object Type: Report
System: The UNT Digital Library
Quarterly Progress Report (open access)

Quarterly Progress Report

The Federal Energy Technology Center (FETC) at Pittsburgh contracted with the MJTRE Corporation to perform Research Guidance Studies that will assist the Center and other relevant offices in the Department of Energy in evaluating and prioritizing research in the areas of coal and natural gas conversion. MITRE was reorganized in December 1995, which resulted in the formation of Mitretek Systems Inc. Mitretek has been performing this work on MITRE's behalf awaiting completion of contract novation to Mitretek. The contract was novated in February 1998 to Mitretek Systems. The overall objectives of this contract are to provide support to DOE in the following areas: (1) technical and economic analyses of current and future coal-based energy conversion technologies and other similar emerging technologies such as coal-waste coprocessing, natural gas conversion, and biomass conversion technologies for the production of fuels, chemicals and electric power,(2) monitor progress in these technologies with respect to technical, economic, and environmental impact (including climate change), (3) conduct specific and generic project economic and technical feasibility studies based on these technologies, (4) identify long-range R&D areas that have the greatest potential for process improvements, and (5) investigate optimum configurations and associated costs for production of high quality energy products …
Date: November 12, 1998
Creator: Gray, David & Tomlinson, Glen
Object Type: Report
System: The UNT Digital Library
Statistical analysis of the particulation of shaped charge jets (open access)

Statistical analysis of the particulation of shaped charge jets

A statistical analysis of shaped charge jet break-up was carried out in order to investigate the role of nonlinear instabilities leading to the particulation of the jet. Statistical methods generally used for studying fluctuations in nonlinear dynamical systems are applied to experimentally measured velocities of the individual particles. In particular we present results suggesting the deviation of non-Gaussian behavior for interparticle velocity correlations, characteristic of nonlinear dynamical systems. Results are presented for two silver shaped charge jets that differ primarily in their material processing. We provide evidence that the particulation of a jet is not random, but has its origin in a deterministic dynamical process involving the nonlinear coupling of two oscillators analogous to the underling dynamics observed in Rayleigh-Benard convection and modeled in the return map of Curry and Yorke.
Date: August 12, 1999
Creator: Minich, R. W.; Baker, E. L. & Schwartz, A. J.
Object Type: Article
System: The UNT Digital Library
Abstracts of the third international conference on the solid-state lasers for application to inertial confinement fusion (open access)

Abstracts of the third international conference on the solid-state lasers for application to inertial confinement fusion

None
Date: June 12, 1998
Creator: Lowdermilk, W H
Object Type: Article
System: The UNT Digital Library
Forensic 3D Scene Reconstruction (open access)

Forensic 3D Scene Reconstruction

Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.
Date: October 12, 1999
Creator: LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN & SMALL,DANIEL E.
Object Type: Article
System: The UNT Digital Library
Tips and Traps in the 14c Bio-AMS Preparation Laboratory (WSam 7) (open access)

Tips and Traps in the 14c Bio-AMS Preparation Laboratory (WSam 7)

Maintaining a contamination free sample preparation lab for biological 14 C AMS requires the same or more diligence as a radiocarbon dating prep lab. Isotope ratios of materials routinely range over 4-8 orders of magnitude in a single experiment, dosing solutions contain thousands of DPM and gels used to separate proteins possess 14 C ratios of 1pMC. Radiocarbon contamination is a legacy of earlier tracer work in most biological laboratories, even if they were never hot labs. Removable surface contamination can be found and monitored using swipes. Contamination can be found on any surface routinely touched: door knobs, light switches, drawer handles, water faucets. In general, all surfaces routinely touched need to be covered with paper, foil, or plastic that can be changed frequently. Shared air supplies can also present problems by distributing hot aerosols throughout a building. Aerosols can be monitored for 14 C content using graphitized coal or fullerene soot mixed with metal powder as an absorber. The monitors can be set out in work spaces for 1-2 weeks and measured by AMS with regular samples. Frequent air changes help minimize aerosol contamination in many cases. Cross contamination of samples can be minimized by using disposable plastic or …
Date: October 12, 1999
Creator: Buchholz, B. A.; Haack, K. W.; Stewart, P. H. & Vogel, J. S.
Object Type: Article
System: The UNT Digital Library
Kaon electroproduction on deuterium. (open access)

Kaon electroproduction on deuterium.

Kaon electroproduction on deuterium and hydrogen targets has been measured at beam energies of 3.245 and 2.445 GeV and momentum transfer Q{sup 2}=0.38 and 0.5 GeV{sup 2}. Associated {Lambda} production off a proton in the deuteron exhibits a quasifree production mechanism. The production of {Sigma}{sup {minus}} off the neutron could be extracted for the first time with reasonable errors.
Date: January 12, 1998
Creator: Reinhold, J.
Object Type: Article
System: The UNT Digital Library
Application of integrated reservoir management and reservoir characterization to optimize infill drilling. Quarterly progress report, June 13, 1995--September 12, 1995 (open access)

Application of integrated reservoir management and reservoir characterization to optimize infill drilling. Quarterly progress report, June 13, 1995--September 12, 1995

At this stage of the reservoir characterization research, the main emphasis is on the geostatistics and reservoir simulation. Progress is reported on geological analysis, reservoir simulation, and reservoir management.
Date: September 12, 1995
Creator: Pande, P.K.
Object Type: Report
System: The UNT Digital Library
Equation of state of insensitive high explosives (open access)

Equation of state of insensitive high explosives

Detonation of an insensitive high explosive formulated with a fluorine containing binder produces a large amount of condensed carbon and gaseous HF product, which transforms into CF{sub 4} as the pressure is increased. The former (carbon condensation) is characterized by slow energy release, while the latter (HF) has no shockwave data. We have identified that these two items are the key factors, which make reliable prediction of the performance of an insensitive high explosive very difficult. This paper describes physical models to address these issues and apply the models to analyze experimental data of LX-17.
Date: August 12, 1998
Creator: Ree, F H; Van Thiel, M & Viecelli, J A
Object Type: Article
System: The UNT Digital Library
Mechanical properties of Ce{sub 0.9}Gd{sub 0.1}O{sub 2-x} and Ce{sub 0.9}Gd{sub 0.1}O{sub 2-x} + Al{sub 2}O{sub 3} composites. (open access)

Mechanical properties of Ce{sub 0.9}Gd{sub 0.1}O{sub 2-x} and Ce{sub 0.9}Gd{sub 0.1}O{sub 2-x} + Al{sub 2}O{sub 3} composites.

The room-temperature elastic moduli, fracture strength, and fracture toughness of dense, fine-grained, pure Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} and composites containing 1.3 and 9.1 wt. % Al{sub 2}O{sub 3} were investigated. Addition of 9.1 wt.% Al{sub 2}O{sub 3} to Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} changed the fracture mode from intergranular to transgranular and increased room-temperature fracture strength from 65 to 125 MPa and fracture toughness from 1.3 to 1.6 MPam{sup 1/2}. In addition, steady-state compressive creep was measured for Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} and the Ce{sub 0.9}Gd{sub 0.1}O{sub 2{minus}x} + 9.1 wt.% Al{sub 2}O{sub 3} composite. The stress exponent {approx}1.3 and the activation energy {approx}480 kJ/mole for Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} suggested diffusional flow controlled by the cations. There was no difference in creep rate between Ce{sub 0.9}Gd{sub 0.1}O{sub 2{minus}x} and the composite.
Date: January 12, 1998
Creator: Routbort, J. L.
Object Type: Article
System: The UNT Digital Library
DOE/FETC Gasis Project (open access)

DOE/FETC Gasis Project

Technical progress on the GAS IS project during the quarter for contract no. DE-AC21 -93 MC281 39 is described. During this period, work was performed on Task 4 Technology Transfer, Task 7: Software Enhancement, Task 8: Reservoir Data System Updates, and Task 9: Supplemental Reservoir Studies.
Date: November 12, 1998
Creator: Hugman, R. H.
Object Type: Report
System: The UNT Digital Library
Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling (open access)

Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.
Date: March 12, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Preliminary report on the groundwater isotope study in the Brentwood Region (open access)

Preliminary report on the groundwater isotope study in the Brentwood Region

Under contract with the City of Brentwood and auxiliary support by the East Contra Costa Irrigation District (ECCID), a preliminary research assessment of the groundwater resources beneath the Brentwood region is complete. The research was performed by an isotope geochemistry approach rather than traditional hydrogeological methods. The isotope approach is inexpensive relative to the traditional methods and has been used here mostly as a tracer that details the source, migration paths, and migration rates of existing groundwater supplies. In addition, the isotope results provide a quantitative framework in which to answer questions important to Brentwood including: (1) What is the long-term and short-term sustainability of the groundwater resources relative to current urban growth projections? (2) How can the good water quality be maximized in groundwater wells under short and long-term groundwater use schemes? (3) What underground areas exist within the Brentwood region that indicate untapped groundwater supplies that may provide plentiful, good quality water? This preliminary report focuses only on the first question. The second and third questions will be addressed in the final report to be completed by January 1, 1995. Furthermore, the conclusions in this preliminary report of how much groundwater is available for use will be incorporated …
Date: October 12, 1994
Creator: Davisson, M. L. & Campbell, K. R.
Object Type: Report
System: The UNT Digital Library
Development of a Drillrod/Telemetry Radar (open access)

Development of a Drillrod/Telemetry Radar

Efficient extraction of deeply buried natural resources is dependent upon accurate geologic models. The model becomes the basis for developing plans for extraction of the resource. Geoscientists working in geothermal and hydrocarbon recovery have a great deal in common with fellow geoscientists working in the mining industry. They appreciate the intractable problem of increasing the depth of investigation to tens of meters from the wellbore. The goal of this project was to develop a borehole radar tool to acquire data within tens of meters from the wellbore. For geothermal and hydrocarbon applications, the tool was to acquire data for mapping fractures surrounding the wellbore. In mining of coal, the radar acquires data for determining coal seam thickness and detecting geologic anomalies ahead of mining.
Date: November 12, 1999
Creator: Raton Technology Research, Inc.
Object Type: Report
System: The UNT Digital Library
Mechanisms and modeling of single-event upset (open access)

Mechanisms and modeling of single-event upset

The basic mechanisms of single-event upset are reviewed, including charge collection in silicon junctions and transistors, and properties of single-event upset in CMOS static random access memory (SRAM) cells. The mechanisms are illustrated through the use of three-dimensional device and circuit simulations. Technology trends and implications for commercial devices are discussed.
Date: October 12, 1998
Creator: Dodd, Paul E.
Object Type: Article
System: The UNT Digital Library
Safe and Fast Quench Recovery of Large Superconducting Solenoids Cooled by Forced Two-Phase Helium Flow. (open access)

Safe and Fast Quench Recovery of Large Superconducting Solenoids Cooled by Forced Two-Phase Helium Flow.

The cryogenic characteristics in energy extraction of the four fifteen-meter-diameter superconducting solenoids of the g-2 magnet are reported in this paper. The energy extraction tests at full-current and half-current of its operating value were deliberately carried out for the quench analyses and evaluation of the cryogenic system. The temperature profiles of each coil mandrel and pressure profiles in its helium cooling tube during the energy extraction are discussed. The low peak temperature and pressure as well as the short recovery time indicated the desirable characteristics of the cryogenic system.
Date: July 12, 1999
Creator: Jia, L. X.
Object Type: Article
System: The UNT Digital Library
Extension of the Application of the generalized pole representation to the treatment of resonance cross sections. (open access)

Extension of the Application of the generalized pole representation to the treatment of resonance cross sections.

One reliable and convenient way of processing the cross sections in the resolved energy region is by use of the generalized pole representation, whereby the Doppler-broadening calculation can be carried out rigorously using the analytical approach. So far, its applications have been limited to cases with resonance parameters specified by the Reich-Moore formalism. Although such an approach, in principle, can be extended to all three remaining representations of resolved resonance parameters specified by the ENDF data format, there is no computational tool for handling such a task at present. Given that Breit-Wigner formalisms are probably the most widely used by any evaluated nuclear data library to represent cross sections, a special effort has to be made to convert the single level and multilevel Breit-Wigner resonance parameters to pole parameters. A FORTRAN computer code BW2PR has been developed for this purpose. Extensive calculations have been performed to demonstrate that the proposed method ensures the conservation of the information contained originally in Breit-Wigner resonance parameters. This will make it possible to apply the exact Doppler-broadening method to a larger collection of nuclides.
Date: March 12, 1999
Creator: Hwang, R. N. & Jammes, C.
Object Type: Article
System: The UNT Digital Library
Sodium carbonate salt transport system (open access)

Sodium carbonate salt transport system

A sodium carbonate salt transport system is required to support the Molten Salt Oxidation system being constructed at Lawrence Livermore National Laboratory. We are embarking on a project to create a national test bed for evaluating mixed waste destruction technologies. This project is called the Mixed Waste Management Facility. It is currently in the second phase of design and will be operational in 1998. One of the first technologies demonstrated in this facility is Molten Salt Oxidation. Molten Salt Oxidation is a thermal process that destroys the organic constituents of mixed and hazardous wastes. Sodium carbonate salt is heated in a reactor vessel to approximately 950{degrees}C. Organic wastes, along with oxidant air, are injected under the pool of molten salt. A catalytic reaction occurs converting the organics into CO{sub 2} and water. Inorganic constituents in the salt such as metals, silica, alumina, and radionuclides remain captured in the salt. Chlorides in the waste feed are converted in the salt to sodium chloride. As these impurities build up in the salt, the salt must be recycled to remove them or else the reaction rate is reduced. Spent salt is periodically taken from the reactor and transported to a salt recycle system. …
Date: September 12, 1995
Creator: Brummond, W.
Object Type: Article
System: The UNT Digital Library
The Kelastic variable wall mining machine. Interim final report (open access)

The Kelastic variable wall mining machine. Interim final report

This machine cuts coal along a longwall face extending up to 500 feet by a rotating auger with bits. The machine also transports the coal that is cut acting as screw conveyor. By virtue of an integral shroud comprising part of the conveyor the machine is also amenable to a separation of the zones where men work from air being contaminated by dust and methane gas by the cutting action. Beginning as single intake air courses, the air separates at the working section where one split provides fresh air to the Occupied Zone (OZ) for human needs and the other split purges and carries away dust and methane from face fragmentation in the Cutting Zone (CZ). The attractiveness of the Variable Wall Mining Machine is that it addresses the limitations of current longwall mining equipment: it can consistently out-produce continuous mining machines and most longwall shearing machines. It also is amenable to configuring an environment, the dual-duct system, where the air for human breathing is separated from dust-laden ventilating air with methane mixtures. The objective of the research was to perform a mathematical and experimental study of the interrelationships of the components of the system so that a computer model …
Date: November 12, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Impact of the ENDF/B-VI Cross Section on the RPV Fluence Determination (open access)

Impact of the ENDF/B-VI Cross Section on the RPV Fluence Determination

The calculations with the broad-group cross-section library Bugle-96, and atom displacement (dpa) cross sections for iron, both derived from ENDF/B-VI data, result in higher calculated fast neutron fluxes, better agreement of calculations with radiometric dosimeter measurements, and significantly slower dpa rate attenuation through pressure vessel walls relative to the results with their predecessors: the Sailor library and ASTM iron dpa cross sections.
Date: September 12, 1999
Creator: Remec, I.
Object Type: Article
System: The UNT Digital Library