Thermoacoustic natural gas liquefier (open access)

Thermoacoustic natural gas liquefier

This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to develop a natural-gas-powered natural-gas liquefier that has absolutely no moving parts and requires no electrical power. It should have high efficiency, remarkable reliability, and low cost. The thermoacoustic natural-gas liquefier (TANGL) is based on our recent invention of the first no-moving-parts cryogenic refrigerator. In short, our invention uses acoustic phenomena to produce refrigeration from heat, with no moving parts. The required apparatus comprises nothing more than heat exchangers and pipes, made of common materials, without exacting tolerances. Its initial experimental success in a small size lead us to propose a more ambitious application: large-energy liquefaction of natural gas, using combustion of natural gas as the energy source. TANGL was designed to be maintenance-free, inexpensive, portable, and environmentally benign.
Date: July 1, 1996
Creator: Swift, G.; Gardner, D.; Hayden, M.; Radebaugh, R. & Wollan, J.
Object Type: Report
System: The UNT Digital Library
Support chemistry, surface area, and preparation effects on sulfided NiMo catalyst activity (open access)

Support chemistry, surface area, and preparation effects on sulfided NiMo catalyst activity

Hydrous Metal Oxides (HMOs) are chemically synthesized materials which contain a homogeneous distribution of ion exchangeable alkali cations that provide charge compensation to the metal-oxygen framework. In terms of the major types of inorganic ion exchangers defined by Clearfield, these amorphous HMO materials are similar to both hydrous oxides and layered oxide ion exchangers (e.g., alkali metal titanates). For catalyst applications, the HMO material serves as an ion exchangeable support which facilitates the uniform incorporation of catalyst precursor species. Following catalyst precursor incorporation, an activation step is required to convert the catalyst precursor to the desired active phase. Considerable process development activities at Sandia National Laboratories related to HMO materials have resulted in bulk hydrous titanium oxide (HTO)- and silica-doped hydrous titanium oxide (HTO:Si)-supported NiMo catalysts that are more active in model reactions which simulate direct coal liquefaction (e.g., pyrene hydrogenation) than commercial {gamma}-Al{sub 2}O{sub 3}-supported NiMo catalysts. However, a fundamental explanation does not exist for the enhanced activity of these novel catalyst materials; possible reasons include fundamental differences in support chemistry relative to commercial oxides, high surface area, or catalyst preparation effects (ion exchange vs. incipient wetness impregnation techniques). The goals of this paper are to identify the key …
Date: June 1, 1996
Creator: Gardner, Timothy J.; McLaughlin, Linda I. & Sandoval, Ronald S.
Object Type: Article
System: The UNT Digital Library
Hydrotreating studies involving NiMo/silica-doped hydrous titanium oxide (HTO:Si)-coated alumina catalysts (open access)

Hydrotreating studies involving NiMo/silica-doped hydrous titanium oxide (HTO:Si)-coated alumina catalysts

For hydrotreating a petroleum-derived liquid feed at 400 C, LHSV = 2. 5 g/g{sub cat}/h, and 1500 psig hydrogen (H) pressure, both HDS and HDN activities were roughly equivalent for a name/TO:Si-coated Amocat catalyst and a commercial alumina-supported name catalyst (Amocat 1C). Superior HDN performance was exhibited by the name/TO: Si-coated Amocat catalyst at low H pressure (500 psig) and after H pressure cycling (1500-500-1500 psig) relative to Amocat 1C. Consistent with previous results obtained on a coal-derived liquid feed, the HDS/HDN results with the petroleum-derived liquid showed that the performance of the name/TO:Si-coated Amocat catalyst on an active metals weight basis exceeded the performance of Amocat 1C at all test conditions. The name/TO:Si-coated Amocat catalyst also showed potentially increased hydrogenation activity, increased resistance to deactivation, and increased yields of lower boiling point distillate fractions, although further work is needed.
Date: July 1, 1996
Creator: Gardner, T.J.; Miller, J.E.; McLaughlin, L.I. & Trudell, D.E.
Object Type: Article
System: The UNT Digital Library
Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY (open access)

Reservoir fracture mapping using microearthquakes: Austin chalk, Giddings field, TX and 76 field, Clinton Co., KY

Patterns of microearthquakes detected downhole defined fracture orientation and extent in the Austin chalk, Giddings field, TX and the 76 field, Clinton Co., KY. We collected over 480 and 770 microearthquakes during hydraulic stimulation at two sites in the Austin chalk, and over 3200 during primary production in Clinton Co. Data were of high enough quality that 20%, 31% and 53% of the events could be located, respectively. Reflected waves constrained microearthquakes to the stimulated depths at the base of the Austin chalk. In plan view, microearthquakes defined elongate fracture zones extending from the stimulation wells parallel to the regional fracture trend. However, widths of the stimulated zones differed by a factor of five between the two Austin chalk sites, indicating a large difference in the population of ancillary fractures. Post-stimulation production was much higher from the wider zone. At Clinton Co., microearthquakes defined low-angle, reverse-fault fracture zones above and below a producing zone. Associations with depleted production intervals indicated the mapped fractures had been previously drained. Drilling showed that the fractures currently contain brine. The seismic behavior was consistent with poroelastic models that predicted slight increases in compressive stress above and below the drained volume.
Date: November 1, 1996
Creator: Phillips, W. S.; Rutledge, J. T.; Gardner, T. L.; Fairbanks, T. D.; Miller, M. E. & Schuessler, B. K.
Object Type: Article
System: The UNT Digital Library
A parallel algorithm for transient solid dynamics simulations with contact detection (open access)

A parallel algorithm for transient solid dynamics simulations with contact detection

Solid dynamics simulations with Lagrangian finite elements are used to model a wide variety of problems, such as the calculation of impact damage to shipping containers for nuclear waste and the analysis of vehicular crashes. Using parallel computers for these simulations has been hindered by the difficulty of searching efficiently for material surface contacts in parallel. A new parallel algorithm for calculation of arbitrary material contacts in finite element simulations has been developed and implemented in the PRONTO3D transient solid dynamics code. This paper will explore some of the issues involved in developing efficient, portable, parallel finite element models for nonlinear transient solid dynamics simulations. The contact-detection problem poses interesting challenges for efficient implementation of a solid dynamics simulation on a parallel computer. The finite element mesh is typically partitioned so that each processor owns a localized region of the finite element mesh. This mesh partitioning is optimal for the finite element portion of the calculation since each processor must communicate only with the few connected neighboring processors that share boundaries with the decomposed mesh. However, contacts can occur between surfaces that may be owned by any two arbitrary processors. Hence, a global search across all processors is required at …
Date: June 1, 1996
Creator: Attaway, S.; Hendrickson, B.; Plimpton, S.; Gardner, D.; Vaughan, C.; Heinstein, M. et al.
Object Type: Article
System: The UNT Digital Library
A new parallel algorithm for contact detection in finite element methods (open access)

A new parallel algorithm for contact detection in finite element methods

In finite-element, transient dynamics simulations, physical objects are typically modeled as Lagrangian meshes because the meshes can move and deform with the objects as they undergo stress. In many simulations, such as computations of impacts or explosions, portions of the deforming mesh come in contact with each other as the simulation progresses. These contacts must be detected and the forces they impart to the mesh must be computed at each timestep to accurately capture the physics of interest. While the finite-element portion of these computations is readily parallelized, the contact detection problem is difficult to implement efficiently on parallel computers and has been a bottleneck to achieving high performance on large parallel machines. In this paper we describe a new parallel algorithm for detecting contacts. Our approach differs from previous work in that we use two different parallel decompositions, a static one for the finite element analysis and dynamic one for contact detection. We present results for this algorithm in a parallel version of the transient dynamics code PRONTO-3D running on a large Intel Paragon.
Date: March 1, 1996
Creator: Hendrickson, B.; Plimpton, S.; Attaway, S.; Vaughan, C. & Gardner, D.
Object Type: Article
System: The UNT Digital Library
Hydrogeologic Investigation of the Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama (open access)

Hydrogeologic Investigation of the Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama

This document describes the geology and hydrogeology at the former Advanced Coal Liquefaction Research and Development (ACLR&D) facility in Wilsonville, Alabama. The work was conducted by personnel from the Oak Ridge National Laboratory Grand Junction office (ORNL/GJ) for the U.S. Department of Energy (DOE) Pittsburgh Energy Technology Center (PETC). Characterization information was requested by PETC to provide baseline environmental information for use in evaluating needs and in subsequent decision-making for further actions associated with the closeout of facility operations. The hydrogeologic conceptual model presented in this report provides significant insight regarding the potential for contaminant migration from the ACLR&D facility and may be useful during other characterization work in the region. The ACLR&D facility is no longer operational and has been dismantled. The site was characterized in three phases: the first two phases were an environmental assessment study and a sod sampling study (APCO 1991) and the third phase the hydraulic assessment. Currently, a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation (RI) to address the presence of contaminants on the site is underway and will be documented in an RI report. This technical memorandum addresses the hydrogeologic model only.
Date: September 1, 1996
Creator: Gardner, F. G.; Kearl, P. M.; Mumby, M. E. & Rogers, S.
Object Type: Report
System: The UNT Digital Library
Long-term-consequence analysis of no action alternative 2 (open access)

Long-term-consequence analysis of no action alternative 2

This report is a supplement to the Waste Isolation Pilot Plant (WIPP) Disposal-Phase Supplemental Environmental Impact Statement. Data and information is described which pertains to estimated impacts from postulated long-term release of radionuclides and hazardous constituents from alpha-bearing wastes stored at major generator/storage sites after loss of institutional control (no action alternative 2). Under this alternative, wastes would remain at the generator sites and not be emplaced at WIPP.
Date: July 1, 1996
Creator: Buck, J.W.; Bagaasen, L.M.; Staven, L.H. & Serne, R.J.
Object Type: Report
System: The UNT Digital Library
Parallel contact detection algorithm for transient solid dynamics simulations using PRONTO3D (open access)

Parallel contact detection algorithm for transient solid dynamics simulations using PRONTO3D

An efficient, scalable, parallel algorithm for treating material surface contacts in solid mechanics finite element programs has been implemented in a modular way for MIMD parallel computers. The serial contact detection algorithm that was developed previously for the transient dynamics finite element code PRONTO3D has been extended for use in parallel computation by devising a dynamic (adaptive) processor load balancing scheme.
Date: September 1, 1996
Creator: Attaway, S. W.; Hendrickson, B. A. & Plimpton, S. J.
Object Type: Article
System: The UNT Digital Library
Rapid bioassessment methods for assessing vegetation toxicity at the Savannah River Site - germination tests and root elongation trials (open access)

Rapid bioassessment methods for assessing vegetation toxicity at the Savannah River Site - germination tests and root elongation trials

Plants form the basis of all ecosystems including wetlands. Although they are the most abundant life form and are the primary producers for all other organisms, they have received the least attention when it comes to environmental matters. Higher plants have rarely been used in ecotoxicity testing and may not respond in the same manner as algae, which have been used more frequently. The introduction of hazardous waste materials into wetland areas has the potential to alter and damage the ecological processes in these ecosystems. Measuring the impact of these contaminants on higher plants is therefore important and needs further research. Higher plants are useful for detecting both herbicidal toxicity and heavy metal toxicity. For phytotoxicity tests to be practical they must be simple, inexpensive, yet sensitive to a variety of contaminants. A difference between seed germination and root elongation tests is that seed germination tests measure toxicity associated with soils directly, while root elongation tests consider the indirect effects of water-soluble constituents that may be present in site samples.
Date: January 1, 1996
Creator: Specht, W. L.; Klaine, S. J. & Hook, D. D.
Object Type: Report
System: The UNT Digital Library
Runoff and erosion from a rapidly eroding pinyon-juniper hillslope (open access)

Runoff and erosion from a rapidly eroding pinyon-juniper hillslope

The dramatic acceleration of erosion associated with the expansion of pinyon-juniper woodlands over the past 100 years has been a widely recognized but poorly understood phenomenon. A more complete understanding will come only through long-term observations of erosion and related factors. To this end, we are conducting a study of a small (1-ha) catchment in a rapidly eroding pinyon-juniper woodland. Since July 1993, we have been collecting data on runoff, erosion, and weather conditions in the catchment, as well as on the topography, soils, and vegetation. Our preliminary results suggest that (1) the catchment is currently in a cycle of accelerated erosion that began concomitant with a shift from ponderosa pine forest to pinyon-juniper woodland that was initiated by a prolonged drought; (2) the intercanopy soils cannot be sustained at the current erosion rates and will be mostly stripped away in about a century; (3) large summer thunderstorms are the most important agents of erosion (4) erosion increases dramatically as the scale increases; (5) runoff makes up <10% of the water budget.
Date: February 1, 1996
Creator: Wilcox, B.P.; Davenport, D. W.; Pitlick, J. & Allen, C.D.
Object Type: Article
System: The UNT Digital Library
K-Basin spent nuclear fuel characterization data report 2 (open access)

K-Basin spent nuclear fuel characterization data report 2

An Integrated Process Strategy has been developed to package, condition, transport, and store in an interim storage facility the spent nuclear fuel (SNF) currently residing in the K-Basins at Hanford. Information required to support the development of the condition process and to support the safety analyses must be obtained from characterization testing activities conducted on fuel samples from the Basins. Some of the information obtained in the testing was reported in PNL-10778, K-Basin Spent Nuclear Fuel Characterization Data Report (Abrefah et al. 1995). That report focused on the physical, dimensional, metallographic examinations of the first K-West (KW) Basin SNF element to be examined in the Postirradiation Testing Laboratory (PTL) hot cells; it also described some of the initial SNF conditioning tests. This second of the series of data reports covers the subsequent series of SNF tests on the first fuel element. These tests included optical microscopy analyses, conditioning (drying and oxidation) tests, ignition tests, and hydrogen content tests.
Date: March 1, 1996
Creator: Abrefah, J.; Gray, W.J.; Ketner, G.L.; Marschman, S.C.; Pyecha, T.D. & Thornton, T.A.
Object Type: Report
System: The UNT Digital Library
Effects of cloudy/clear air mixing and droplet pH on sulfate aerosol formation in a coupled chemistry/climate global model (open access)

Effects of cloudy/clear air mixing and droplet pH on sulfate aerosol formation in a coupled chemistry/climate global model

In this paper we will briefly describe our coupled ECHAM/GRANTOUR model, provide a detailed description of our atmospheric chemistry parameterizations, and discuss a couple of numerical experiments in which we explore the influence of assumed pH and rate of mixing between cloudy and clear air on aqueous sulfate formation and concentration. We have used our tropospheric chemistry and transport model, GRANTOUR, to estimate the life cycle and global distributions of many trace species. Recently, we have coupled GRANTOUR with the ECHAM global climate model, which provides several enhanced capabilities in the representation of aerosol interactions.
Date: October 1, 1996
Creator: Molenkamp, C.R.; Atherton, C.A.; Penner, J.E. & Walton, J.J.
Object Type: Article
System: The UNT Digital Library
Review of private sector and Department of Energy treatment, storage, and disposal capabilities for low-level and mixed low-level waste (open access)

Review of private sector and Department of Energy treatment, storage, and disposal capabilities for low-level and mixed low-level waste

Private sector capacity for treatment, storage, and disposal (TSD) of various categories of radioactive waste has been researched and reviewed for the Idaho National Engineering Laboratory (INEL) by Lockheed Idaho Technologies Company, the primary contractor for the INEL. The purpose of this document is to provide assistance to the INEL and other US Department of Energy (DOE) sites in determining if private sector capabilities exist for those waste streams that currently cannot be handled either on site or within the DOE complex. The survey of private sector vendors was limited to vendors currently capable of, or expected within the next five years to be able to perform one or more of the following services: low-level waste (LLW) volume reduction, storage, or disposal; mixed LLW treatment, storage, or disposal; alpha-contaminated mixed LLW treatment; LLW decontamination for recycling, reclamation, or reuse; laundering of radioactively-contaminated laundry and/or respirators; mixed LLW treatability studies; mixed LLW treatment technology development. Section 2.0 of this report will identify the approach used to modify vendor information from previous revisions of this report. It will also illustrate the methodology used to identify any additional companies. Section 3.0 will identify, by service, specific vendor capabilities and capacities. Because this document …
Date: March 1, 1996
Creator: Willson, R. A.; Ball, L. W.; Mousseau, J. D. & Piper, R. B.
Object Type: Report
System: The UNT Digital Library
Measuring Energy-Saving Retrofits: Experiences from the Texas Loanstar Program (open access)

Measuring Energy-Saving Retrofits: Experiences from the Texas Loanstar Program

In 1988 the Governor`s Energy Management Center of Texas received approval from the US Department of Energy to establish a $98.6 million state-wide retrofit demonstration revolving loan program to fund energy-conserving retrofits in state, public school, and local government buildings. As part of this program, a first-of-its-kind, statewide Monitoring and Analysis Program (MAP) was established to verify energy and dollar savings of the retrofits, reduce energy costs by identifying operational and maintenance improvements, improve retrofit selection in future rounds of the LoanSTAR program, and initiate a data base of energy use in institutional and commercial buildings located in Texas. This report discusses the LoanSTAR MAP with an emphasis on the process of acquiring and analyzing data to measure savings from energy conservation retrofits when budgets are a constraint. This report includes a discussion of the program structure, basic measurement techniques, data archiving and handling, data reporting and analysis, and includes selected examples from LoanSTAR agencies. A summary of the program results for the first two years of monitoring is also included.
Date: February 1, 1996
Creator: Haberl, J. S.; Reddy, T. A.; Claridge, D. E.; Turner, W. D.; O`Neal, D. L. & Heffington, W. M.
Object Type: Report
System: The UNT Digital Library
Inertial fusion energy: A clearer view of the environmental and safety perspectives (open access)

Inertial fusion energy: A clearer view of the environmental and safety perspectives

If fusion energy is to achieve its full potential for safety and environmental (S&E) advantages, the S&E characteristics of fusion power plant designs must be quantified and understood, and the resulting insights must be embodied in the ongoing process of development of fusion energy. As part of this task, the present work compares S&E characteristics of five inertial and two magnetic fusion power plant designs. For each design, a set of radiological hazard indices has been calculated with a system of computer codes and data libraries assembled for this purpose. These indices quantify the radiological hazards associated with the operation of fusion power plants with respect to three classes of hazard: accidents, occupational exposure, and waste disposal. The three classes of hazard have been qualitatively integrated to rank the best and worst fusion power plant designs with respect to S&E characteristics. From these rankings, the specific designs, and other S&E trends, design features that result in S&E advantages have been identified. Additionally, key areas for future fusion research have been identified. Specific experiments needed include the investigation of elemental release rates (expanded to include many more materials) and the verification of sequential charged-particle reactions. Improvements to the calculational methodology are …
Date: November 1, 1996
Creator: Latkowski, J.F.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Lacunarity as a texture measure for a tropical forest landscape (open access)

Lacunarity as a texture measure for a tropical forest landscape

Fragmentation and loss of tropical forest cover alters terrestrial plant and animal population dynamics, reduces biodiversity and carbon storage capacity, and, as a global phenomenon could affect regional and global climate patterns. Lacunarity as a texture measure can offer a simple solution to characterize the texture of tropical forest landscape and determine spatial patterns associated with ecological processes. Lacunarity quantifies the deviation from translational invariance by describing the distribution of gaps within a binary image at multiple scales. As lacunarity increases, the spatial arrangement of tropical forest gaps will also increase. In this study, we used the Spatial Modeler in Imagine as a graphic programming tool to calculate lacunarity indices for a tropical forest landscape in Southern Mexico and Northern Guatemala. Lacunarity indices were derived from classified Landsat MSS images acquired in 1974 and 1984. Random-generated binary images were also used to derive lacunarity indices and compared with the lacunarity of forest patterns derived from the classified MSS images. Tropical forest area declined about 17%, with most of the forest areas converted into pasture/grassland for grazing. During this period, lacunarity increased about 25%. Results of this study suggest that tropical forest fragmentation could be quantified with lacunarity measures. The study …
Date: January 1, 1996
Creator: Su, Haiping & Krummel, J.
Object Type: Article
System: The UNT Digital Library
Ranking of Texas reservoirs for application of carbon dioxide miscible displacement (open access)

Ranking of Texas reservoirs for application of carbon dioxide miscible displacement

Of the 431 reservoirs screened, 211 projected revenue that exceeded cost, ie, were profitable. Only the top 154 reservoirs, however, showed a profit greater than 30%. The top 10 reservoirs predicted a profit of at least 80%. Six of the top ten were Gulf Coast sandstones. The reservoirs are representative of the most productive discoveries in Texas; they account for about 72% of the recorded 52 billion barrels oil production in the State. Preliminary evaluation in this study implied that potential production from CO{sub 2}-EOR could be as much as 4 billion barrels. In order to enhance the chances of achieving this, DOE should consider a targeted outreach program to the specific independent operators controlling the leases. Development of ownership/technical potential maps and an outreach program should be initiated to aid this identification.
Date: April 1, 1996
Creator: Ham, J
Object Type: Report
System: The UNT Digital Library
Coronal structure inferred from remote sensing observations (open access)

Coronal structure inferred from remote sensing observations

Remote-sensing observations of the Sun and inner heliosphere are reviewed to appraise our understanding of the mix of the mechanisms that heat the corona and accelerate the solar wind. An assessment of experimental uncertainties and the basic assumptions needed to translate measurables into physical models, reveals very large fundamental uncertainties in our knowledge of coronal structure near the Sun. We develop a time-dependent, filamentary model of the extended corona that is consistent with a large number of remote sensing observations of the solar atmosphere and the solar wind.
Date: September 1, 1996
Creator: Feldman, W.C.
Object Type: Article
System: The UNT Digital Library
The Perry Daily Journal (Perry, Okla.), Vol. 102, No. 301, Ed. 1 Thursday, February 1, 1996 (open access)

The Perry Daily Journal (Perry, Okla.), Vol. 102, No. 301, Ed. 1 Thursday, February 1, 1996

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: February 1, 1996
Creator: Watson, Milo W.
Object Type: Newspaper
System: The Gateway to Oklahoma History
National Ignition Facility project acquisition plan (open access)

National Ignition Facility project acquisition plan

The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility (NIF) Project. The scope of the plan describes the procurement activities and acquisition strategy for the following phases of the NIF Project, each of which receives either plant and capital equipment (PACE) or other project cost (OPC) funds: Title 1 and 2 design and Title 3 engineering (PACE); Optics manufacturing facilitization and pilot production (OPC); Convention facility construction (PACE); Procurement, installation, and acceptance testing of equipment (PACE); and Start-up (OPC). Activities that are part of the base Inertial Confinement Fusion (ICF) Program are not included in this plan. The University of California (UC), operating Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory, and Lockheed-Martin, which operates Sandia National Laboratory (SNL) and the University of Rochester Laboratory for Laser Energetics (UR-LLE), will conduct the acquisition of needed products and services in support of their assigned responsibilities within the NIF Project structure in accordance with their prime contracts with the Department of Energy (DOE). LLNL, designated as the lead Laboratory, will have responsibility for all procurements required for construction, installation, activation, and startup of the NIF.
Date: April 1, 1996
Creator: Callaghan, R.W.
Object Type: Report
System: The UNT Digital Library
The Perry Daily Journal (Perry, Okla.), Vol. 103, No. 120, Ed. 1 Monday, July 1, 1996 (open access)

The Perry Daily Journal (Perry, Okla.), Vol. 103, No. 120, Ed. 1 Monday, July 1, 1996

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: July 1, 1996
Creator: Watson, Milo W.
Object Type: Newspaper
System: The Gateway to Oklahoma History
Progress on the physics of ignition for radiation driven inertial confinement fusion (ICF) targets (open access)

Progress on the physics of ignition for radiation driven inertial confinement fusion (ICF) targets

Extensive modeling of proposed National Ignition Facility (NIF) ignition targets has resulted in a variety of targets using different materials in the fuel shell, using driving temperatures which range from 250-300 eV, and requiring energies from < 1 MJ up to the full 1. 8 MJ design capability of NIF. Recent Nova experiments have shown that hohlraum walls composed of a mixture of high-z materials could result in targets which require about 20% less energy. Nova experiments are being used to quantify benefits of beam smoothing in reducing stimulated scattering processes and laser beam filamentation for proposed gas-filled hohlraum targets on NIF. Use of Smoothing by Spectral Dispersion with 2-3 {Angstrom}of bandwidth results in <4-5% of Stimulated Raman Scattering and less than about 1% Stimulated Brillouin Scattering for intensities less than about 2x10{sup 15}W/cm{sup 2} for this type of hohlraum. The symmetry in Nova gas- filled hohlraums is affected by the gas fill. A large body of evidence now exists which indicates that this effect is due to laser beam filamentation which can be largely controlled by beam smoothing. We present here the firs 3-D simulations of hydrodynamic instability for the NIF point design capsule. These simulations, with the HYDRA …
Date: September 1, 1996
Creator: Lindl, J. D. & Marinak, M. M.
Object Type: Article
System: The UNT Digital Library
The Perry Daily Journal (Perry, Okla.), Vol. 103, No. 146, Ed. 1 Thursday, August 1, 1996 (open access)

The Perry Daily Journal (Perry, Okla.), Vol. 103, No. 146, Ed. 1 Thursday, August 1, 1996

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: August 1, 1996
Creator: Watson, Milo W.
Object Type: Newspaper
System: The Gateway to Oklahoma History