Plasma electrode pockels cell for the National Ignition Facility (open access)

Plasma electrode pockels cell for the National Ignition Facility

The National Ignition Facility (NIF), now under construction at Lawrence Livermore National Laboratory, will be the largest laser fusion facility ever built. The NIF laser architecture is based on a multi-pass power amplifier to reduce cost and maximize performance. A key component in this laser design is an optical switch that closes to trap the optical pulse in the cavity for four gain passes and then opens to divert the optical pulse out of the amplifier cavity. The switch is comprised of a Pockels cell and a polarizer and is unique because it handles a beam that is 40 cm x 40 cm square and allows close horizontal and vertical beam spacing. Conventional Pockels cells do not scale to such large apertures or the square shape required for close packing. Our switch is based on a Plasma-Electrode Pockels Cell (PEPC). In a PEPC, low-pressure helium discharges (1-2 kA) are formed on both sides of a thin slab of electro-optic material. Typically, we use KH{sub 2}PO{sub 4 } crystals (KDP). The discharges form highly conductive, transparent sheets that allow uniform application of a high-voltage pulse (17 kV) across the crystal. A 37 cm x 37 cm PEPC has been in routine …
Date: July 28, 1998
Creator: Alger, T.; Biltoft, P.; Boley, C. D.; Fochs, S.; Funkhouser, B. & Rhodes, M. A.
Object Type: Article
System: The UNT Digital Library
TFA Multiyear Program Plan FY99-FY03 (open access)

TFA Multiyear Program Plan FY99-FY03

None
Date: September 28, 1998
Creator: Allen, R. W.
Object Type: Report
System: The UNT Digital Library
ARAC dispersion modeling of the August 1998 Tracy, California tire fire (open access)

ARAC dispersion modeling of the August 1998 Tracy, California tire fire

At about 4:30 pm PDT on Friday, August 7, 1998 a fire ignited the large tire disposal pit of Royster Tire Co. on Macarthur Drive about 5 km (3 miles) south of downtown Tracy, California. While providing on-scene mutual aid late Friday night, the LLNL Fire Department called and requested that the Atmospheric Release Advisory Capability (ARAC) make a plume forecast for Saturday. The response team in the field was interested in the forecasted location as well as an estimate of potential health effects on the following day. Not having any previous experience with tire fire source terms, ARAC assessors used a constant unit source rate (1 g/s) of particulate and produced plots showing only the location of the ground-level normalized time-integrated air concentrations from the smoke plume. Very early Saturday morning the assessors faxed plots of ground-level smoke air concentrations forecasted for Saturday from 6 am through 6 pm PDT to the Tracy Fire Emergency Operations Center. (As a part of standard procedure, before delivering the plots, the assessors notified ARAC's DOE sponsor.) Fortunately due to the intense heat from the fire, the dense black smoke immediately lofted into the air preventing high ground-level concentrations close to the tire …
Date: August 28, 1998
Creator: Aluzzi, F J; Baskett, R L; Bowen, B M; Foster, C S; Pace, J C; Pobanz, B et al.
Object Type: Report
System: The UNT Digital Library
National INFOSEC technical baseline: multi-level secure systems (open access)

National INFOSEC technical baseline: multi-level secure systems

The purpose of this report is to provide a baseline description of the state of multilevel processor/processing to the INFOSEC Research Council and at their discretion to the R&D community at large. From the information in the report, it is hoped that the members of the IRC will be aware of gaps in MLS research. A primary purpose is to bring IRC and the research community members up to date on what is happening in the MLS arena. The review will attempt to cover what MLS products are still available, and to identify companies who still offer MLS products. We have also attempted to identify requirements for MLS by interviewing senior officers of the Intelligence community as well as those elements of DoD and DOE who are or may be interested in procuring MLS products for various applications. The balance of the report consists of the following sections; a background review of the highlights of the developments of MLS, a quick summary of where we are today in terms of products, installations, and companies who are still in the business of supplying MLS systems [or who are developing MLS system], the requirements as expressed by senior members of the Intelligence …
Date: September 28, 1998
Creator: Anderson, J P
Object Type: Report
System: The UNT Digital Library
Effect of Fluid Flow on Inclusion Coarsening in Low-Alloy Steel Welds (open access)

Effect of Fluid Flow on Inclusion Coarsening in Low-Alloy Steel Welds

Oxide inclusions form in welds because of deoxidation reactions in the weld pool. These inclusions control the weld microstructure development. Thermodynamic and kinetic calculation of oxidation reaction can describe inclusion characteristics such as number density, size, and composition. Experimental work has shown that fluid-flow velocity gradients in the weld pool can accelerate inclusion growth by collision and coalescence. Moreover, fluid flow in welds can transport inclusions to different temperature regions that may lead to repeated dissolution and growth of inclusions. These phenomena are being studied with the help of computational coupled heat transfer, fluid-flow, thermodynamic, and kinetic models. The results show that the inclusion formation in steel welds can be described as a function of the welding processes, process parameters, and steel composition.
Date: February 28, 1998
Creator: Babu, S.S.; David, S.A.; DebRoy, T. & Hong, T.
Object Type: Article
System: The UNT Digital Library
Development of a GaAs-Based Monolithic Surface Acoustic Wave Integrated Chemical Microsensor (open access)

Development of a GaAs-Based Monolithic Surface Acoustic Wave Integrated Chemical Microsensor

An oscillator technology using surface acoustic wave delay lines integrated with GaAs MESFET electronics has been developed for GaAs-based integrated microsensor applications. Oscillators with frequencies of 470, 350, and 200 MHz have been designed and fabricated. These oscillators are also promising for other rf applications.
Date: October 28, 1998
Creator: Baca, A. G.; Casalnuovo, S. C.; Drummond, T. J.; Frye, G. C.; Heller, E. J.; Hietala, V. M. et al.
Object Type: Article
System: The UNT Digital Library
Project W-320, 241-C-106 sluicing: Civil/structural calculations. Volume 1 (open access)

Project W-320, 241-C-106 sluicing: Civil/structural calculations. Volume 1

This supporting document has been prepared to make the FDNW civil/structural calculations for Project W-320 readily retrievable.
Date: July 28, 1998
Creator: Bailey, J. W.
Object Type: Report
System: The UNT Digital Library
Sparking rates measured on the CRITS RFQ (open access)

Sparking rates measured on the CRITS RFQ

During the test of the LEDA injector on the CRITS RFQ, an automatic data acquisition system has been implemented. The purpose was to measure the sparking rate of this CW RFQ. The RF level has some influences on vacuum, but there is no evidence of any reciprocal effect. The raw sparking rate is very difficult to interpret, since burst of sparks bias the statistics. A more convenient and useful interpretation is the number of sparking seconds. At the nominal field level (1.75 Kilp), the sparking-second rate is 0.5 per minute without beam. It strongly depends on the field, with a logarithmic law: 4.5 decade/Kilp. With beam, the sparking rate jumps to 3.0 per minute. As far as tested, it depends neither on the beam current (20 to 80 mA) nor on the field (1.5 to 1.7 Kilp tested). With sparking rates as measured here, one could not hope to build an RFQ that would be free of sparks over a several months continuous operation. Such a requirement, based on an extrapolation of the curves presented here, would lead to a maximal electric field much lower than the Kilpatrick value, an unreasonable requirement for a functional RFQ. A conclusion is that …
Date: May 28, 1998
Creator: Balleyguier, P.
Object Type: Report
System: The UNT Digital Library
Pataha [Creek] Model Watershed: 1997 Habitat Projects, Annual Progress Report. (open access)

Pataha [Creek] Model Watershed: 1997 Habitat Projects, Annual Progress Report.

The projects outlined in detail on the attached project reports are a few of the many projects implemented in the Pataha Creek Model Watershed since it was selected as a model in 1993. Up until this year, demonstration sites using riparian fencing, off site watering facilities, tree and shrub plantings and upland conservation practices were used for information and education and was the main focus of the implementation phase of the watershed plan. These practices are the main focus of the watershed plan to reduce the majority of the sediment entering the stream.
Date: October 28, 1998
Creator: Bartels, Duane
Object Type: Report
System: The UNT Digital Library
221-U Facility concrete and reinforcing steel evaluations specification for the canyon disposition initiative (CDI) (open access)

221-U Facility concrete and reinforcing steel evaluations specification for the canyon disposition initiative (CDI)

This describes a test program to establish the in-situ material properties of the reinforced concrete in Building 221-U for comparison to the original design specifications. Field sampling and laboratory testing of concrete and reinforcing steel structural materials in Building 221-U for design verification will be undertaken. Forty seven samples are to be taken from radiologically clean exterior walls of the canyon. Laboratory testing program includes unconfined compressive strength of concrete cores, tensile strength of reinforcing steel, and petrographic examinations of concrete cores taken from walls below existing grade.
Date: May 28, 1998
Creator: Baxter, J. T.
Object Type: Report
System: The UNT Digital Library
Assuring safety in the National Ignition Facility (open access)

Assuring safety in the National Ignition Facility

The National Ignition Facility (NIF) is a US Department of Energy inertial confinement laser fusion facility currently under construction at the Lawrence Livermore National Laboratory (LLNL). The NIF mission is to achieve inertial confinement fusion (ICF) ignition, access physical conditions in matter of interest to nuclear weapons effects testing, contribute to the development of inertial fusion for electrical power production, and to support basic science and technology.
Date: April 28, 1998
Creator: Becker, D R; Brereton, S J; Brumburgh, G P; Pryatel, J A; Wolfe, C R & Yatabe, J M
Object Type: Article
System: The UNT Digital Library
Joint inversion of geophysical data for site characterization and restoration monitoring (open access)

Joint inversion of geophysical data for site characterization and restoration monitoring

The purpose of this project is to develop a computer code for joint inversion of seismic and electrical data, to improve underground imaging for site characterization and remediation monitoring. The computer code developed in this project will invert geophysical data to obtain direct estimates of porosity and saturation underground, rather than inverting for seismic velocity and electrical resistivity or other geophysical properties. This is intended to be a significant improvement in the state-of-the-art of underground imaging, since interpretation of data collected at a contaminated site would become much less subjective. Potential users include DOE scientists and engineers responsible for characterizing contaminated sites and monitoring remediation of contaminated sites. In this three-year project, we use a multi-phase approach consisting of theoretical and numerical code development, laboratory investigations, testing on available laboratory and borehole geophysics data sets, and a controlled field experiment, to develop practical tools for joint electrical and seismic data interpretation.
Date: May 28, 1998
Creator: Berge, P. A.
Object Type: Article
System: The UNT Digital Library
Active and passive computed tomography for nondestructive assay (open access)

Active and passive computed tomography for nondestructive assay

Traditional gamma-ray methods used to characterize nuclear waste introduce errors that are related to non-uniform measurement responses associated with unknown radioactive source and matrix material distributions. These errors can be reduced by applying an active and passive tomographic technique (A&PCT) developed at the Lawrence Livermore National Laboratory (LLNL). The technique uses an external radioactive source and active tomography to map the attenuation within a waste barrel as a function of mono-energetic gamma-ray energy. Passive tomography is used to localize and identify specific radioactive waste within the same container. Reconstruction of the passive data using the attenuation maps at specific energies allows internal waste radioactivity to be corrected for any overlying heterogeneous materials, thus yielding an absolute assay of the waste activity. LLNL and Bio-Imaging Research, Inc. have collaborated in a technology transfer effort to integrate an A&PCT assay system into a mobile waste characterization trailer. This mobile system has participated in and passed several formal DOE-sponsored performance demonstrations, tests and evaluations. The system is currently being upgraded with multiple detectors to improve throughput, automated gamma-ray analysis code to simplify the assay, and a new emission reconstruction code to improve accuracy
Date: October 28, 1998
Creator: Bernardi, R. T.; Camp, D. E.; Clard, D.; Jackson, J. A.; Martz, H. E.; Decman, D. J. et al.
Object Type: Article
System: The UNT Digital Library
Statistical on-chip interconnect modeling : an application of automatic differentiation. (open access)

Statistical on-chip interconnect modeling : an application of automatic differentiation.

Automatic differentiation is a technique for computing derivatives accurately and efficiently with minimal human effort. We employed this technique to generate derivative information of FCAP2 (2-D) and FCAP3 (3-D) programs that simulate the parasitic effects of interconnects and devices. This derivative information is used in the statistical modeling of worst-case interconnect delays and on-chip crosstalks. The ADIC (Automatic Differentiation in C) tool generated new versions of FCAP2 and FCAP3 programs that compute both the original results and the derivative information. Given the ANSI C source code for the function, ADIC generates new code that computes derivatives of the model output with respect to the input parameters. We report on the use of automatic differentiation and divided difference approaches for computing derivatives for FCAP3 programs. The results show that ADIC-generated code computes derivatives more accurately, more robustly, and faster than the divided difference approach.
Date: September 28, 1998
Creator: Bischof, C.; Roh, L.; Chang, N.; Lee, K.; Kanevsky, V.; Nakagawa, O. S. et al.
Object Type: Article
System: The UNT Digital Library
Analysis of Hydrogen Depletion Using a Scaled Passive Autocatalytic Recombiner (open access)

Analysis of Hydrogen Depletion Using a Scaled Passive Autocatalytic Recombiner

Hydrogen depletion tests of a scaled passive autocatalytic recombine (pAR) were performed in the Surtsey test vessel at Sandia National Laboratories (SNL). The experiments were used to determine the hydrogen depletion rate of a PAR in the presence of steam and also to evaluate the effect of scale (number of cartridges) on the PAR performance at both low and high hydrogen concentrations.
Date: October 28, 1998
Creator: Blanchat, Thomas K. & Malliakos, Asimios
Object Type: Article
System: The UNT Digital Library
Design and Implementation of a C02 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in a Shallow Carbonate Approaching Waterflood Depletion (open access)

Design and Implementation of a C02 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells in a Shallow Carbonate Approaching Waterflood Depletion

The first project objective is to utilize reservoir characterization and advanced technologies to optimize the design of a carbon dioxide (CO2) project for the South Cowden Unit (SCU) located in Ector County, Texas. The SCU is a mature, relatively small, shallow shelf carbonate unit nearing waterflood depletion. The second project objective is to demonstrate the performance and economic viability of the project in the field. All work during the fourth quarter falls within the demonstration project.
Date: April 28, 1998
Creator: Bles, J. Scott & Dollens, Kimberly B.
Object Type: Report
System: The UNT Digital Library
Model Watershed Development in Eastern Washington, Administrative Project Support, Annual Progress Report (open access)

Model Watershed Development in Eastern Washington, Administrative Project Support, Annual Progress Report

The purpose of the Model Watershed Coordinator Grant was to help impact water quality and fisheries habitat concerns within the Asotin Creek Watershed by developing relationships between local landowners and resource agencies in the area.
Date: October 28, 1998
Creator: Bottman, Bob; Bartels, Duane & Johnson, Bradley J.
Object Type: Report
System: The UNT Digital Library
Idaho Model Watershed Project : Annual Report to the Bonneville Power Administration January 1, 1997 - December 31, 1997. (open access)

Idaho Model Watershed Project : Annual Report to the Bonneville Power Administration January 1, 1997 - December 31, 1997.

The Model Watershed Project was initiated in the fall of 1992 with a grant from Bonneville Power Administration. The objective of this project is to protect, enhance and restore anadromous and resident fish habitat and achieve and maintain a balance between resource protection and resource use on a holistic watershed basis.
Date: October 28, 1998
Creator: Bradbury, Allen & Slavin, Katie
Object Type: Report
System: The UNT Digital Library
Bench-Scale Enhanced Sludge Washing and Gravity Settling of Hanford Tank S-107 Sludge (open access)

Bench-Scale Enhanced Sludge Washing and Gravity Settling of Hanford Tank S-107 Sludge

This report summarizes the work performed with sludge from Hanford Site single-shell Tank 241-S-107 during FY 98. The tests described in this report support the development of the baseline Hanford tank sludge pretreatment flowsheet that includes the enhanced sludge washing (ESW) and settle/decant process.
Date: September 28, 1998
Creator: Brooks, K. P.; Bontha, J. R.; Golcar, G. R.; Myers, R. L.; Rappe, K. G. & Rector, D. R.
Object Type: Report
System: The UNT Digital Library
Working group meeting on heavy vehicle aerodynamic drag: presentations and summary of comments and conclusion (open access)

Working group meeting on heavy vehicle aerodynamic drag: presentations and summary of comments and conclusion

The first Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held at Sandia National Laboratories (SNL) in Albuquerque, New Mexico on August 28, 1998. The purpose of the meeting was to review the proposed Multi-Year Program Plan (MYPP) and provide an update on the Group"s progress. In addition, the technical details of each organization"s activities were presented and discussed. Presentations were given by representatives from the Department of Energy (DOE) Office of Transportation Technology Office of Heavy Vehicle Technology (OHVT), Lawrence Livermore National Laboratory (LLNL), SNL, University of Southern California (USC), California Institute of Technology (Caltech), and NASA Ames Research Center. These presenters are part of a DOE appointed Technical Team assigned to developing the MYPP. The goal of the MYPP is to develop and demonstrate the ability to simulate and analyze aerodynamic flow around heavy truck vehicles using existing and advanced computational tools (A Multi-Year Program Plan for the Aerodynamic Design of Heavy Vehicles, R. McCallen, D. McBride, W. Rutledge, F. Browand, A. Leonard, .I. Ross, UCRL-PROP- 127753 Dr. Rev 2, May 1998). This report contains the technical presentations (viewgraphs) delivered at the Meeting, briefly summarizes the comments and conclusions from the Meeting participants, and outlines the future …
Date: September 28, 1998
Creator: Browand, Fred; Gutierrez, Walter; Leonard, Anthony; McBride, Don; McCallen, Rose; Ross, Jim et al.
Object Type: Report
System: The UNT Digital Library
Third-Order Transport with MAD Input: A Computer Program for Designing Charged Particle Beam Transport Systems (open access)

Third-Order Transport with MAD Input: A Computer Program for Designing Charged Particle Beam Transport Systems

TRANSPORT has been in existence in various evolutionary versions since 1963. The present version of TRANSPORT is a first-, second-, and third-order matrix multiplication computer program intended for the design of static-magnetic beam transport systems.
Date: October 28, 1998
Creator: Brown, Karl
Object Type: Report
System: The UNT Digital Library
Tank characterization technical sampling basis (open access)

Tank characterization technical sampling basis

Tank Characterization Technical Sampling Basis (this document) is the first step of an in place working process to plan characterization activities in an optimal manner. This document will be used to develop the revision of the Waste Information Requirements Document (WIRD) (Winkelman et al. 1997) and ultimately, to create sampling schedules. The revised WIRD will define all Characterization Project activities over the course of subsequent fiscal years 1999 through 2002. This document establishes priorities for sampling and characterization activities conducted under the Tank Waste Remediation System (TWRS) Tank Waste Characterization Project. The Tank Waste Characterization Project is designed to provide all TWRS programs with information describing the physical, chemical, and radiological properties of the contents of waste storage tanks at the Hanford Site. These tanks contain radioactive waste generated from the production of nuclear weapons materials at the Hanford Site. The waste composition varies from tank to tank because of the large number of chemical processes that were used when producing nuclear weapons materials over the years and because the wastes were mixed during efforts to better use tank storage space. The Tank Waste Characterization Project mission is to provide information and waste sample material necessary for TWRS to define …
Date: April 28, 1998
Creator: Brown, T. M.
Object Type: Report
System: The UNT Digital Library
Tucannon Model Watershed 1997 Habitat Projects : Annual Progress Report Project Period: January 1, 1997 to March 31, 1998. (open access)

Tucannon Model Watershed 1997 Habitat Projects : Annual Progress Report Project Period: January 1, 1997 to March 31, 1998.

The Tucannon Model Watershed 1997 habitat projects were designed to address critical limiting factors identified through the watershed assessment and Plan development. Construction elements were composed of bioengineering techniques designed to increase salmonid habitat complexity, insure stream bank and geomorphic stability, and reduce stream temperature and sediments in spawning gravels. Cooperation and agreement between landowners and resource agencies for restoring resource conditions has grown due to project success and is expected to continue for the benefit of all.
Date: October 28, 1998
Creator: Bruegman, Terry & Nordheim, Debby
Object Type: Report
System: The UNT Digital Library
Electrical resistance tomography of unsaturated flow and transport in Yucca Mountain (open access)

Electrical resistance tomography of unsaturated flow and transport in Yucca Mountain

Electrical Resistance Tomography (ERT), a new geophysical imaging technique, was used to study the movement of a tracer through the test block at the Unsaturated Zone Transport Test (UZTT) at Busted Butte, Nevada. Data were collected four times starting in July and ending in early September, 1998. ERT baseline images show a resistivity structure which is consistent with the known lithology in the rear part of the test block. There appears to be a low resistivity region in the front half of the block, particularly near the bottom. Difference images from August 19 and September 9 show clear and consistent resistivity decreases in the region near injection holes 18, 20, and 21 which can be associated with the injection of conductive water. The images show very little effect in the region around the other injection holes, 23, and 24 through 27 where far less water was injected. Difference images from August 19 and September 9 show resistivity decreases which could be interpreted as water moving down into the block. This is the same region which has an anomalously low resistivity in the baseline image. These results should be considered preliminary, and are subject to further interpretation.
Date: December 28, 1998
Creator: Buettner, H M; Bussod, G; Daily, W & Ramirez, A
Object Type: Article
System: The UNT Digital Library