Ultra-intense, short pulse laser-plasma interactions with applications to the fast ignitor (open access)

Ultra-intense, short pulse laser-plasma interactions with applications to the fast ignitor

Due to the advent of chirped pulse amplification (CPA) as an efficient means of creating ultra-high intensity laser light (I > 5{times}10{sup 17} W/cm{sup 2}) in pulses less than a few picoseconds, new ideas for achieving ignition and gain in DT targets with less than 1 megajoule of input energy are currently being pursued. Two types of powerful lasers are employed in this scheme: (1) channeling beams and (2) ignition beams. The current state of laser-plasma interactions relating to this fusion scheme will be discussed. In particular, plasma physics issues in the ultra-intense regime are crucial to the success of this scheme. We compare simulation and experimental results in this highly nonlinear regime.
Date: April 1, 1995
Creator: Wilks, S. C.; Kruer, W. L.; Young, P. E.; Hammer, J. & Tabak, M.
Object Type: Article
System: The UNT Digital Library
Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1 (open access)

Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1

The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.
Date: April 1, 1995
Creator: Lyon, Chesley R.; Blanchard, Clifton F. & Whitt, Laura H.
Object Type: Report
System: The UNT Digital Library
Tests of Low Scale Gravity via Gauge Boson Pair Production in {gamma}{gamma} Collisions (open access)

Tests of Low Scale Gravity via Gauge Boson Pair Production in {gamma}{gamma} Collisions

Arkani-Hamed, Dimopoulos and Dvali have recently proposed that gravity may become strong at energies near 1 TeV thus removing the hierarchy problem. This scenario can be tested in several ways at present and future colliders. In this paper we examine the exchange of towers of Kaluza-Klein gravitons and their influence on the production of pairs of massive gauge bosons in {gamma}{gamma} collisions. These tower exchanges are shown to lead to a new dimension-8 operator that can significant alter the Standard Model expectations for these processes. The role of polarization for both the initial state photons and the final state gauge bosons in improving sensitivity to graviton exchange is emphasized. We find that the discovery reach for graviton tower exchange in the {gamma}{gamma} {r_arrow} W{sup +}W{sup {minus}} channel to be significantly greater than for any other process so far examined.
Date: April 19, 1999
Creator: Rizzo, Thomas G.
Object Type: Report
System: The UNT Digital Library
User requirements for ISEARCH document imaging system (open access)

User requirements for ISEARCH document imaging system

This requirements document lists items that are needed for exploring replacement software for the existing imaging system for the RMIS/ISEARCH system.
Date: April 10, 1997
Creator: Galbreath, E.D.
Object Type: Report
System: The UNT Digital Library
Transformations in organic sulfur speciation during maturation of Monterey shale: Constraints from laboratory experiments (open access)

Transformations in organic sulfur speciation during maturation of Monterey shale: Constraints from laboratory experiments

A series of hydrous pyrolysis experiments were conducted at temperatures ranging from 125 to 360C at 350 bars pressure to examine variations in sulfur speciation during thermal maturation of Monterey shale. The total sediment, kerogen and bitumen from each experiment in addition to unheated representatives were analyzed via x-ray absorption spectroscopy, pyrolysis-gas chromatography, {sup 30}NMR spectrometry, elemental analysis, thin-layer chromatography and reflected light microscopy. Based on these measurements, it was possible to recognize three distinct temperature regimes, within which the type and amount of sulfur in the analyzed fractions underwent transformations: (1) between 150 and 225C significant proportion of kerogen-bound sulfur is lost probably due to the collapse of polysulfide bridges; (2) between 225 and 275C, cleavage of -S-S- and -S-C- linkages within the kerogen is believed to occur, resulting in substantial production of polar sulfur-rich bitumen; (3) above 275C total bitumen yields as well as the proportion of bitumen sulfur decrease, while C-C bond scission leads to increased yields of saturated and aromatic hydrocarbons. The results from this study clearly and quantitatively establish a link between organically-bound sulfur, and more specifically, organic polysulfides, and the low-temperature evolution of soluble petroleum-like products (bitumen) from sulfur-rich source rocks.
Date: April 1995
Creator: Nelson, B. C.; Eglinton, T. I.; Seewald, J. S.; Vairavamurthy, M. A. & Miknis, F. P.
Object Type: Report
System: The UNT Digital Library
Advanced Emissions Control Development Program (open access)

Advanced Emissions Control Development Program

The objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. Ideally, the project aim is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPS), fabric filters (baghouse), and wet flue gas desulfurization. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate and hydrogen chloride. Following the construction and evaluation of a representative air toxics test facility in Phase I, Phase II focused on the evaluation of mercury and several other air toxics emissions. The AECDP is jointly funded by the United States Department of Energy's Federal Energy Technology Center (DOE), the Ohio Coal Development Office within the Ohio Department of Development (oCDO), and Babcock& Wilcox-a McDermott company (B&W).
Date: April 1, 1998
Creator: A.P.Evans; Redinger, K.E. & Holmes, M.J.
Object Type: Report
System: The UNT Digital Library
Test plan for the data acquisition and management system for monitoring the fuel oil spill at the Sandia National Laboratories installation in Livermore, California (open access)

Test plan for the data acquisition and management system for monitoring the fuel oil spill at the Sandia National Laboratories installation in Livermore, California

This report describes the formal test plan that will be used for the data acquisition and management system developed to monitor a bioremediation study by Argonne National Laboratory in association with Sandia National Laboratories. The data acquisition and management system will record the site data during the bioremediation and assist experts in site analysis. The three major subsystems of this system are described in detail in this report. In addition, this report documents the component- and system-level test procedures that will be implemented at each phase of the project. Results of these test procedures are documented in this report.
Date: April 1, 1995
Creator: Widing, M.A.; Dominiak, D.M.; Leser, C.C.; Peerenboom, J.P. & Manning, J.F.
Object Type: Report
System: The UNT Digital Library
A Practical Guide for Commissioning Existing Buildings (open access)

A Practical Guide for Commissioning Existing Buildings

Although this guide focuses on the retrocommissioning process and its advantages, all three types of commissioning--retrocommissioning, commissioning, and recommissioning--play an equally important role in ensuring that buildings perform efficiently and provide comfortable, safe, and productive work environments for owners and occupants. For new construction and retrofit projects, commissioning should be incorporated early, during design, and last throughout the length of the project. For buildings that were never commissioned, the retrocommissioning process can yield a wealth of cost-saving opportunities while enhancing a building's environment. Finally, once a building is commissioned or retrocommissioned, incorporating recommissioning into the organization's O and M program (by periodically reapplying the original diagnostic testing and checklist procedures) helps ensure that cost savings and other benefits gained from the original process persist over time.
Date: April 1, 1999
Creator: Haasl, T. & Sharp, T.
Object Type: Report
System: The UNT Digital Library
Numerical transport theory; Final report (open access)

Numerical transport theory; Final report

The basic problem addressed in the project was that of accelerating the iterative convergence of Discrete Ordinates (S{sub N}) problems. Important previous work on this problem, much of which was done at LANL, has shown that the Diffusion Synthetic Acceleration (DSA) method can be a very effective acceleration procedure. However, in two-dimensional geometries, only the diamond differenced S{sub N} equations have been efficiently solved using DSA. This is because, for the 2-D diamond-differenced S{sub N} equations, the standard DSA procedure leads to a relatively simple discretized low-order diffusion equation that for many problems can be efficiently solved by a multigrid method. For other discretized versions of the S{sub N} equations, the standard DSA procedure leads to much more complicated discretizations of the low-order diffusion equation that have not been efficiently solved by multigrid (or other) methods. In this project, we have developed a new procedure to obtain discretized diffusion equations for DSA-accelerating the convergence of the S{sub N} equations using certain lumped discontinuous finite element spatial differencing methods. The idea is to use an asymptotic analysis for the derivation of the discretized diffusion equation. This is based on the fact that diffusion theory is an asymptotic limit of transport theory. …
Date: April 1, 1994
Creator: Larsen, E.W.
Object Type: Report
System: The UNT Digital Library
Calculations supporting evaluation of potential environmental standards for Yucca Mountain (open access)

Calculations supporting evaluation of potential environmental standards for Yucca Mountain

The Energy Policy Act of 1992, Section 801 (US Congress, 1992) provides for the US Environmental Protection Agency (EPA) to contract the National Academy of Sciences (NAS) to conduct a study and provide findings and recommendations on reasonable standards for the disposal of high-level wastes at the Yucca Mountain site. The NAS study is to provide findings and recommendations which include, among other things, whether a health-based standard based on dose to individual members of the public from releases to the accessible environment will provide a reasonable standard for the protection of the health and safety of the public. The EPA, based upon and consistent with the findings and recommendations of the NAS, is required to promulgate standards for protection of the public from releases from radioactive materials stored or disposed of in a repository at the Yucca Mountain site. This document presents a number of different ``simple`` analyses of undisturbed repository performance that are intended to provide input to those responsible for setting appropriate environmental standards for a potential repository at the Yucca Mountain site in Nevada. Each of the processes included in the analyses has been simplified to capture the primary significance of that process in containing or …
Date: April 1, 1994
Creator: Duguid, J. O.; Andrews, R. W.; Brandstetter, E.; Dale, T. F. & Reeves, M.
Object Type: Report
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
Beam lifetime and beam brightness in ALS (open access)

Beam lifetime and beam brightness in ALS

Beam lifetime in ALS is dominated by the Touschek scattering. Measurements of lifetime in single-bunch mode with estimates of bunch dimensions obtained from undulator radiation data are consistent with expectations (t=1.8 hours at 1.25 mA per bunch). However, the lifetime is significantly longer in multi-bunch mode (t=ll hours at 400 mA per 320 bunches). This discrepancy has been traced to an increase in the momentum spread and bunch length in the beam caused by longitudinal coupled-bunch motions driven by higher-order modes in the rf cavities. The increased momentum spread leads to a significant degradation in the undulator spectral performance. Feedback stabilization of the coupled-bunch motion improves the spectral characteristics of the undulator beam at the expense of beam lifetime. We observe an increase of {approximately}200% in beam lifetime by operating at the betatron coupling resonance.
Date: April 1, 1995
Creator: Kim, C.; Jackson, A. & Warwick, A.
Object Type: Article
System: The UNT Digital Library
Waste form development and characterization in pyrometallurgical treatment of spent nuclear fuel. (open access)

Waste form development and characterization in pyrometallurgical treatment of spent nuclear fuel.

Electrometallurgical treatment is a compact, inexpensive method that is being developed at Argonne National Laboratory to deal with spent nuclear fuel, primarily metallic and oxide fuels. In this method, metallic nuclear fuel constituents are electrorefined in a molten salt to separate uranium from the rest of the spent fuel. Oxide and other fuels are subjected to appropriate head end steps to convert them to metallic form prior to electrorefining. The treatment process generates two kinds of high-level waste--a metallic and a ceramic waste. Isolation of these wastes has been developed as an integral part of the process. The wastes arise directly from the electrorefiner, and waste streams do not contain large quantities of solvent or other process fluids. Consequently, waste volumes are small and waste isolation processes can be compact and rapid. This paper briefly summarizes waste isolation processes then describes development and characterization of the two waste forms in more detail.
Date: April 16, 1998
Creator: Ackerman, J.
Object Type: Article
System: The UNT Digital Library
Development of radiation detectors based on hydrogenated amorphous silicon and its alloys (open access)

Development of radiation detectors based on hydrogenated amorphous silicon and its alloys

Hydrogenated amorphous silicon and related materials have been applied to radiation detectors, utilizing their good radiation resistance and the feasibility of making deposits over a large area at low cost. Effects of deposition parameters on various material properties of a-Si:H have been studied to produce a material satisfying the requirements for specific detection application. Thick(-{approximately}50 {mu}m), device quality a-Si:H p-i-n diodes for direct detection of minimum ionizing particles have been prepared with low internal stress by a combination of low temperature growth, He-dilution of silane, and post annealing. The structure of the new film contained voids and tiny crystalline inclusions and was different from the one observed in conventional a-Si:H. Deposition on patterned substrates was attempted as an alternative to controlling deposition parameters to minimize substrate bending and delamination of thick a-Si:H films. Growth on an inversed-pyramid pattern reduced the substrate bending by a factor of 3{approximately}4 for the same thickness film. Thin (0.1 {approximately} 0.2 {mu}m) films of a-Si:H and a-SiC:H have been applied to microstrip gas chambers to control gain instabilities due to charges on the substrate. Light sensitivity of the a-Si:H sheet resistance was minimized and the surface resistivity was successfully` controlled in the range of 10{sup …
Date: April 1, 1995
Creator: Hong, Wan-Shick
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Theory and numerical application of subsurface flow and transport for transient freezing conditions (open access)

Theory and numerical application of subsurface flow and transport for transient freezing conditions

Protective barriers are being investigated for the containment of radioactive waste within subsurface environments. Predicting the effectiveness of cryogenic barriers and near-surface barriers in temperate or arctic climates requires capabilities for numerically modeling subsurface flow and transport for freezing soil conditions. A predictive numerical model is developed herein to simulate the flow and transport of radioactive solutes for three-phase (water-ice-air) systems under freezing conditions. This physically based model simulates the simultaneous flow of water, air, heat, and radioactive solutes through variably saturated and variably frozen geologic media. Expressions for ice (frozen water) and liquid water saturations as functions of temperature, interfacial pressure differences, and osmotic potential are developed from nonhysteretic versions of the Brooks and Corey and van Genuchten functions for soil moisture retention. Aqueous relative permeability functions for variably saturated and variably frozen geologic media are developed from the Mualem and Burdine theories for predicting relative permeability of unsaturated soil. Soil deformations, caused by freezing and melting transitions, are neglected. Algorithms developed for predicting ice and liquid water saturations and aqueous-phase permeabilities were incorporated into the finite-difference based numerical simulator STOMP (Subsurface Transport Over Multiple Phases). Application of the theory is demonstrated by the solution of heat and mass …
Date: April 1, 1995
Creator: White, M. D.
Object Type: Report
System: The UNT Digital Library
Test plan for surface and subsurface examinations of K-east and K-west fuel elements (open access)

Test plan for surface and subsurface examinations of K-east and K-west fuel elements

The test plan for subsurface examinations on damaged K East and K West Basin fuel elements is presented. The purpose of these examinations is to inspect damaged areas on the fuel elements for the presence of voids, sludge, or broken fuel, and to obtain samples from the damaged areas for subsequent characterization tests.
Date: April 14, 1997
Creator: Pitner, A.L.
Object Type: Report
System: The UNT Digital Library
Proceedings of the natural gas RD&D contractors review meeting, Volume I (open access)

Proceedings of the natural gas RD&D contractors review meeting, Volume I

This report contains papers which were presented at the natural gas contractors review meeting held on April 4-6, 1995. Topics were concerned with resource and reserves, low permeability reservoir characterization, natural fracture detection, drilling, completion, and stimulation, and natural gas upgrading. Individual papers were processed separately for the United States Department of Energy databases.
Date: April 1, 1995
Creator: Malone, R.D.
Object Type: Article
System: The UNT Digital Library
Evaporative oxidation treatability test report (open access)

Evaporative oxidation treatability test report

In 1992, Congress passed the Federal Facilities Compliance Act that requires the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs). In response to the need for mixed-waste treatment capacity where available off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed wastes with treatment options and develop a strategy for treatment of its mixed wastes. DOE-AL manages operations at nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment capacity to treat wastes at the sites where the wastes are generated. Treatment processes used for mixed waste not only must address the hazardous component (i.e., meet LDRs) but also must contain the radioactive component in a form that allows final disposal while protecting workers, the public, and the environment. On the basis of recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (GJPO) are evaporative oxidation, thermal desorption, and treated …
Date: April 1, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Use of Simulation for the Programs for the Modeling of the Next Linear Collider (open access)

Use of Simulation for the Programs for the Modeling of the Next Linear Collider

The Next Linear Collider is an electron-positron accelerator unprecedented in its size, energy, and tight tolerances. We describe the suite of simulation tools which are widely used in designing and modeling the performance of the NLC. In order to achieve a uniform beamline description and permit simulation of all facets of the collider, an extended version of the Standard Input Format (xSIF) has been developed and implemented in MAD and DIMAD. We discuss several enhancements to the MAD and DIMAD calculation engines necessary to properly simulate the most challenging regions of the facility. We also describe enhancements to LIAR which allow it to be used as the tracking engine for a tuning/feedback simulation written in MATLAB. Finally, we discuss the additional software needed to model the beam stabilization and tuning processes.
Date: April 23, 1999
Creator: Tenenbaum, Peter G
Object Type: Report
System: The UNT Digital Library
NNWSI [Nevada Nuclear Waste Storage Investigations] waste form testing at Argonne National Laboratory; Semiannual report, January--June 1988 (open access)

NNWSI [Nevada Nuclear Waste Storage Investigations] waste form testing at Argonne National Laboratory; Semiannual report, January--June 1988

The Chemical Technology Division of Argonne National Laboratory is performing experiments in support of the waste package development of the Yucca Mountain Project (formerly the Nevada Nuclear Waste Storage Investigations Project). Experiments in progress include (1) the development and performance of a durability test in unsaturated conditions, (2) studies of waste form behavior in an irradiated atmosphere, (3) studies of behavior in water vapor, and (4) studies of naturally occurring glasses to be used as analogues for waste glass behavior. This report documents progress made during the period of January--June 1988. 21 refs., 37 figs., 12 tabs.
Date: April 1990
Creator: Bates, J. K.; Gerding, T. J.; Ebert, W. L.; Mazer, J. J. & Biwer, B. M.
Object Type: Report
System: The UNT Digital Library
Gaseous release of carbon-14: Why the high level waste regulations should be changed (open access)

Gaseous release of carbon-14: Why the high level waste regulations should be changed

The high-level nuclear waste regulations pertaining to gaseous release of carbon-14 from a repository should be changed to allow greater release, for several reasons. Some of them are as follows. First, the total amount of carbon-14 that would be placed in a repository is small compared to that produced naturally in the atmosphere by cosmic rays. Second, the dose that would result to an individual from total release of repository carbon-14 would be very small compared to that from natural radiation sources and would be well below the ``Below Regulatory Concern`` criterion. Third, the limits on gaseous carbon-14 release from a repository have been set unreasonably low compared to the limits set for carbon-14 release from other fuel cycle facilities. Fourth, the additional cost for waste packages to attempt to meet the regulations for carbon-14 release would likely be of the order of a billion dollars or more, too high to be justified by the small reduction in dose that might result. 32 refs.
Date: April 1, 1991
Creator: Van Konynenburg, R.A.
Object Type: Article
System: The UNT Digital Library
Overture: object-oriented tools for overset grid applications (open access)

Overture: object-oriented tools for overset grid applications

The Overture framework is an object-oriented environment for solving partial differential equations in two and three space dimensions. It is a collection of C++ libraries that enables the use of finite difference and finite volume methods at a level that hides the details of the associated data structures. Overture can be used to solve problems in complicated, moving geometries using the method of overlapping grids. It has support for grid generation, difference operators, boundary conditions, data-base access and graphics. Short sample code segments are presented to show the power of this approach.
Date: April 28, 1999
Creator: Brown, D L; Henshaw, W D & Quinlan, D J
Object Type: Article
System: The UNT Digital Library
A computerized welder qualification record and tracking system (open access)

A computerized welder qualification record and tracking system

Accurately tracking welder qualification and assigning welders to jobs for which they are qualified is becoming more important as customers increasingly demand improved quality and conformance to industry standards. A computerized welder qualification records and tracking system (WPQ) was developed at the Oak Ridge Y-12 Plant to assist the user in this process. The system enables the user to consistently generate welder qualification records with minimal effort and increased accuracy, relate the welder qualification limits with the limits of the welding procedure specification, generate a printout which reports essential information for selecting qualified welders, and provide a method for updating welders based on process usage as permitted by the codes. Codes addressed by the system include American Society of Mechanical Engineers (ASME) Section IX, American Welding Society (AWS) D1.1, AWS D1.3 and AWS D9.1
Date: April 27, 1994
Creator: Davis, J.N.; Etzler, D.J.; Fletcher, D.R.; Jessee, R.M.; Wilson, L.O.; Evans, J.C. et al.
Object Type: Article
System: The UNT Digital Library
Constraining local 3-D models of the saturated-zone, Yucca Mountain, Nevada (open access)

Constraining local 3-D models of the saturated-zone, Yucca Mountain, Nevada

A qualitative three-dimensional analysis of the saturated zone flow system was performed for a 8 km {times} 8 km region including the potential Yucca Mountain repository site. Certain recognized geologic features of unknown hydraulic properties were introduced to assess the general response of the flow field to these features. Two of these features, the Solitario Canyon fault and the proposed fault in Drill Hole Wash, appear to constrain flow and allow calibration.
Date: April 1, 1994
Creator: Barr, G.E. & Shannon, S.A.
Object Type: Article
System: The UNT Digital Library