The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 50 million pulses. This was achieved by improving the ohmic contacts through the incorporation of a doped layer beneath the PCSS contacts which is very effective in the suppression of filament formation and alleviating current crowding to improve the longevity of PCSS. Virtually indefinite, damage-free operation is now possible at much higher current levels than before. The inherent damage-free current capacity of the switch depends on the thickness of the doped layers and is at least 100A for a dopant diffusion depth of 4pm. The contact metal has a different damage mechanism and the threshold for damage ({approximately}40A) is not further improved beyond a dopant diffusion depth of about 2{micro}m. In a diffusion-doped contact switch, the switching performance is not degraded when contact metal erosion occurs. This paper will compare thermal diffusion and epitaxial growth as approaches to doping the contacts. These techniques will be contrasted in terms of the fabrication issues and device characteristics.

The continuity equation for electromagnetic (EM) energy flow is used to describe radiation flow in the transport regime. The scheme of a discrete representation of H_z and a stochastic representation of H_x, H_y gives an effectively continuous representation of directed energy in the x-y plane, such that the ray effect of transport theory is absent. Since the in-plane amplitudes are generated at each time step, it is necessary to store only the perpendicular amplitudes and the results appear to be robust with respect to the coarse of this discretization.

Enhancer of gene silencing 1 (egs1) is an Arabidopsis mutant that enhances post-transcriptional gene silencing of the rolB gene introduced by genetic engineering (transgene). The goal of our proposal was cloning EGS1 based on its map position. Although we screened more than 2000 chromosomes for recombination, we were unable to get closer than 2 cM to the gene. We experienced an unexpected tendency of the post-transcriptionally silenced transgene to switch to a more stable silenced state. This made it impossible to select egs1 homozygotes for map based cloning. This forced us to reconsider our cloning strategy. One possibility would have been to use a different transgene as the target of gene silencing. We tested two other transgenes. Both encoded proteins unrelated to the first but they were all expressed from the same type of promoter and they all had a similar tendency to become post-transcriptionally silenced. After screening over 80 F2 segregants from each cross between our egs1 mutant and Arabidopsis of the same ecotype homozygous for the new transgene, we were disappointed to find that the egs1 mutation did not enhance post-transcription silencing of the two new genes. In 80 plants we expected to have between 4 and 6 …

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This Interface Control Document (ICD) describes the interface between the Double-Shell Tank (DST) System and T Plant. T Plant generates waste during decontamination activities. These facilities do not have a direct physical interface since the waste will be moved by tank trailer to the 204-AR waste unloading facility. The purpose of the ICD process is to formalize working agreements between the River Protection Project (WP) DST System and organization/companies internal and external to RPP. This ICD has been developed as part of the requirements basis for design of the DST System to support the Phase I Privatization effort.

The local strain and texture in Al interconnect wires have been investigated using white and monochromatic x-ray microbeams on the MHATTCAT undulator beam line at the Advanced Photon Source. Intergrain and intragrain orientations were obtained with ~0.01 degree sensitivity using white beam measurements on wide Al pads (~100 Mu-m) and thin (2 Mu-m) Al wires. Orientation changes of up to 1 degree were found within individual grains of the (111) textured Al interconnects. Deviatoric strain measurements indicate small intragranular strain variations, but intergranular strain variations were found to be quite large.

Two instances of research facilities responding to public scrutiny will be discussed. The first concerns emissions from a �tritium labeling facility� operated at Lawrence Berkeley National Laboratory (LBNL); the second deals with releases of plutonium from Lawrence Livermore National Laboratory (LLNL). There are many parallels between these two cases, both of which are still ongoing. In both, the national laboratory is the acknowledged source of low-level (by regulatory standards) radioactive contamination in the community. A major purpose of both investigations is to determine the degree of the contamination and the threat it poses to public health and the environment. The examining panel or committee is similarly constituted in the two cases, including representatives from all four categories of stakeholders: decision makers; scientists and other professionals doing the analysis/assessment; environmental activist or public interest groups; and �ordinary� citizens (nearly everyone else not in one or more of the first three camps). Both involved community participation from the beginning. The levels of outrage over the events triggering the assessment are comparable; though �discovered� or �appreciated� only a few years ago, the release of radiation in both cases occurred or began occurring more than a decade ago. The meetings have been conducted in …

The effect of shadowing on the early state of ultrarelativistic heavy ion collisions is investigated along with transverse energy and hard process production, specifically Drell-Yan, J/psi, and Upsilon production. We choose several parton distributions and parameterizations of nuclear shadowing, as well as the spatial dependence of shadowing, to study the influence of shadowing on relevant observables. Results are presented for Au+Au collisions at sqrt(s{sub NN}) = 200 GeV and Pb+Pb collisions at sqrt(s{sub NN}) =5.5 TeV.

Operational Final Test Report for Integrated Systems, Project W-030 (Phase 2 test, RECIRC and HIGH-HEAT Modes). Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks, including upgraded vapor space cooling and filtered venting of tanks AY101, Ay102, AZ101, AZ102.

The Richland Operations Office (RL) and Office of River Protection (ORP) are pleased to issue the attached Pollution Prevention Progress Report. We have just met the most aggressive waste reduction and A recycling goals to date and are publishing this report to recognize A the site's progress, and to ensure it will sustain success beyond 1 Fiscal Year 2000. This report was designed to inform the been made by RL and ORP in Waste Minimization (WMin) and Pollution Prevention (P2). RL, ORP and their contractors are committed to protecting the environment, and we reiterate pollution prevention should continue to be at the forefront of the environmental cleanup and research efforts. As you read the attached report, we believe you will see a clear demonstration of RL and ORP's outstanding performance as it has been responsible and accountable to the nation, its employees, and the community in which we live and work. commitment that all employees have for environmental stewardship. The report provides useful information about the U.S. Department of Energy's (DOE'S) environmental policy and programs, and contains countless examples of waste minimization projects. This year was the first year our site received the White House Closing the Circle in the …

The following description and any attachments and references are provided to the Washington State Department of Health (WDOH), Division of Radiation Protection, Air Emissions & Defense Waste Section as a notice of construction (NOC) in accordance with Washington Administrative Code (WAC) 246-247, Radiation Protection - Air Emissions. WAC 246-247-060, ''Applications, registration, and licensing'', states ''This section describes the information requirements for approval to construct, modify, and operate an emission unit. Any NOC requires the submittal of information listed in Appendix A,'' Appendix A (WAC 246-247-110) lists the requirements that must be addressed. Additionally, the following description, attachments, and references are provided to the U.S. Environmental Protection Agency (EPA) as an NOC, in accordance with Title 40 Code of Federal Regulations (CFR), Part 61, ''National Emission Standards for Hazardous Air Pollutants.'' The information required for submittal to the EPA is specified in 40 CFR 61.07. The potential emissions from this activity are estimated to provide less than 0.1 millirem/year total effective dose equivalent to the hypothetical offsite maximally exposed individual, and commencement is needed within a short time. Therefore, this application also is intended to provide notification of the anticipated date of initial startup in accordance with the requirement listed in …

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

This sampling and analysis plan (SAP) identifies the type, quantity, and quality of data needed to support characterization of the sludge that remains in Tank 241-2-361. The procedures described in this SAP are based on the results of the 241-2-361 Sludge Characterization Data Quality Objectives (DQO) (BWHC 1999) process for the tank. The primary objectives of this project are to evaluate the contents of Tank 241-2-361 in order to resolve safety and safeguards issues and to assess alternatives for sludge removal and disposal.

This tank sampling and analysis plan (TSAP) identifies the sample collection, laboratory analysis, quality assurance/quality control (QA/QC) objectives for the characterization of catch tank 241-ER-311 vapor space.

Understanding turbulence and mix in compressible flows is of fundamental importance to real-world applications such as chemical combustion and supernova evolution. The ability to run in three dimensions and at very high resolution is required for the simulation to accurately represent the interaction of the various length scales, and consequently, the reactivity of the intermixing species. Toward this end, we have carried out a very high resolution (over 8 billion zones) 3-D simulation of the Richtmyer-Meshkov instability and turbulent mixing on the IBM Sustained Stewardship TeraOp (SST) system, developed under the auspices of the Department of Energy (DOE) Accelerated Strategic Computing Initiative (ASCI) and located at Lawrence Livermore National Laboratory. We have also undertaken an even higher resolution proof-of-principle calculation (over 24 billion zones) on 5832 processors of the IBM, which executed for over an hour at a sustained rate of 1.05 Tflop/s, as well as a short calculation with a modified algorithm that achieved a sustained rate of 1.18 Tflop/s. The full production scientific simulation, using a further modified algorithm, ran for 27,000 timesteps in slightly over a week of n-all time using 3840 processors of the IBM system, clocking a sustained throughput of roughly 0.6 teraflop per second. …

This document identifies administrative controls that are established for the operating contractor of the B Plant facility during the B Plant surveillance and maintenance phase. When approved by the DOE-RL, this document is part of the B Plant safety authorization basis. Look for the associated B Plant Surveillance and Maintenance Phase Safety Analysis Report, HNF-3358.

Safe interim dry storage of spent nuclear fuel (SNF) must be maintained for a minimum of twenty years according to the Code of Federal Regulations. The most important variable that must be regulated by dry storage licensees in order to meet current safety standards is the temperature of the SNF. The two currently accepted models to define the maximum allowable initial storage temperature for SNF are based on the diffusion controlled cavity growth (DCCG) failure mechanism proposed by Raj and Ashby. These models may not give conservative temperature limits. Some have suggested using a strain-based failure model to predict the maximum allowable temperatures, but we have shown that this is not applicable to the SNF as long as DCCG is the assumed failure mechanism. Although the two accepted models are based on the same fundamental failure theory (DCCG), the researchers who developed the models made different assumptions, including selection of some of the most critical variables in the DCCG failure equation. These inconsistencies are discussed together with recommended modifications to the failure models based on more recent data.

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained from piping, equipment, or facilities connected to tank 241-ER-311. The purpose of this sampling event is to obtain information about the effects of the argon purge gas added to tank 241-ER-311. Vapor samples will be taken in the encasement of transfer lines, at the ER-151 diversion box, and, as necessary, any other locations connected to tank 241-ER-311. Combustible gas, ammonia, and organic vapor levels will be field-measured using hand-held instruments. Vapor samples will be taken and shipped to the Pacific Northwest National Laboratory (PNNL) for analysis. This test plan identifies the sample collection, laboratory analysis, quality assurance, and reporting objectives for this data collection effort. The plan also provides the requirements for vapor measurements performed in the field.

The VISA (Visible to Infrared SASE Amplifier) project is designed to be a SASE-FEL driven to saturation in the sub-micron wavelength region. Its goal is to test various aspects of the existing theory of Self-Amplified Spontaneous Emission, as well as numerical codes. Measurements include: angular and spectral distribution of the FEL light at the exit and inside of the undulator; electron beam micro-bunching using CTR; single-shot time resolved measurements of the pulse profile, using auto-correlation technique and FROG algorithm. The diagnostics are designed to provide maximum information on the physics of the SASE-FEL process, to ensure a close comparison of the experimental results with theory and simulations.

A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium rich solids. The calciner and some of its associated equipment were previously tested with non-radioactive chemicals to demonstrate operability.

Recent developments in the design of the Next Linear Collider (NLC) positron source based on updated beam parameters are described. The unpolarized NLC positron source [1,2] consists of a dedicated 6.2 GeV S-band electron accelerator, a high-Z positron production target, a capture system and an L-band positron linac. The 1998 failure of the SLC target, which is currently under investigation, may lead to a variation of the target design. Progress towards a polarized positron source is also presented. A moderately polarized positron beam colliding with a highly polarized electron beam results in an effective polarization large enough to explore new physics at NLC. One of the schemes towards a polarized positron source incorporates a polarized electron source, a 50 MeV electron accelerator, a thin target for positron production and a new capture system optimized for high-energy, small angular-divergence positrons. The yield for such a process, checked using the EGS4 code, is of the order of 10{sup -3}. The EGS4 code has being enhanced to include the effect of polarization in bremsstrahlung and pair-production process.

By attending the conference, participants learn about new and planned OEM vehicle and engine technologies; studies comparing Diesel and gasoline emissions to natural gas; new state and federal legislation; and innovative marketing programs they can use to help sell their products and services.

This Phase II SBIR program was conducted to demonstrate the ability of a circulating fluidized bed (CFB) of flyash to cause particle agglomeration and consequent reduction in the quantity of fine particulate emissions from the system. Another objective was to show that carbon addition to the bed would result in the removal of mercury compounds from the flue gas at carbon utilization levels significantly better than duct injection of activated carbon. The pilot-scale testing was carried out in 1997. The pilot-scale fluid bed reactor was a 1000 CFM system, drawing gas from a slipstream of the exhaust of a 325 MW coal-fired boiler. Flue gas for the pilot unit was drawn downstream of the air preheater and returned to the same unit. Particle agglomeration testing was carried out for which the parameters of gas flow rate and water evaporation rate were varied, and the particle size distribution leaving the fluid bed system was monitored. The bed was able to cause a reduction in total particulate concentration by a factor of 10 and in fine particulate concentration by a factor of 5, and it was found that the best agglomeration of particles was obtained with simultaneous water spray evaporation. Tests were …

This analysis was performed by the Management and Operating Contractor (M&O) Safety Assurance Department to identify and document the internal hazards and preliminary events associated with preclosure operations of the Monitored Geologic Repository (MGR). Internal hazards are those hazards presented by operation of the facility and associated processes. These are in contrast to external hazards which involve natural phenomena and external man-made hazards. The hazard analysis methodology used in this analysis provides a systematic means to identify facility hazards and associated events that may result in radiological consequences to the public and facility worker during the MGR preclosure period. The events are documented in a preliminary events list and are intended to be used as input to the MGR Design Basis Event (DBE) selection process. It is expected that the results from this analysis will undergo further screening and analysis based on the criteria that apply to the performance of DBE analyses for the preclosure period of repository operation. As the MGR design progresses, this analysis will be reviewed to ensure no new hazards are introduced and that previously evaluated hazards have not increased in severity.