Design criteria are described, and test results are presented, for prototype ALS undulator beam position monitors. The design is based on monitors presently in use at NSLS, with modifications to account for the widely varying and large K values of the undulators to be installed at the ALS. In particular, we have modified the design to simplify the thermal engineering and we have explored techniques to suppress the response of the monitors to soft photons, so that the beam position can be determined by measuring the higher energy photons which are better collimated. 4 refs., 8 figs.

It is argued that quantum measurements do pose a problem, within the context created by the fundamental aim of science, which is identified as the construction of a cohesive, comprehensive, and rationally coherent idea of the nature of the world in which we live. Models of nature are divided into two classes: (1), those in which there is a selection process that, for any possible measurement, would, if that measurement were to be performed, pick out one single outcome, and, (2), all others. It is proved that any model of class that reproduces the predictions of quantum theory must violate the condition that there be no faster-than-light influences of any kind. This result is used to motivate the study of models in which unitary evolution is maintained and there is no selection of unique outcomes. A consideration of ontic probabilities, historical records, and the form of the mind-brain connection leads to an elaboration of the Everett many-worlds interpretation that appears to provide the basis of satisfactory solution of the measurement problem. 18 refs.

The process described in this paper is intended to convert mixed waste containing toxic organic compounds (not heavy metals) to ordinary radioactive waste, which is treatable. The process achieves its goal by oxidizing hydrocarbons to CO{sub 2} and H{sub 2}O. Other atoms that may be present in the toxic organic generally are converted to nonhazardous anions such as sulfate and phosphate. This electro chemical conversion is performed at conditions of temperature and pressure that are just moderately above ambient conditions. Gaseous hydroxides and oxyhydroxides that are formed by many radionuclides during incineration cannot form in this process. 1 ref., 3 figs.

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We have conducted as extensive series of laser damage measurements on highly reflective (HR) dielectric coatings which have yielded 1064-nm thresholds as high as 40 J/cm{sup 2} for 8- to 10-ns pulses at pulse-repetition frequencies (PRF) of 10 Hz. Moreover, by laser conditioning these coatings with subthreshold pulses, the thresholds of some coatings were raised to levels exceeding 70 J/cm{sup 2}. These are the highest threshold dielectric HR coatings that we have tested in this regime. The coatings were originally developed to produce HR-overcoated metal mirrors for free-electron-laser (FEL) applications at high PRF. Our tests included coatings deposited on both dielectric substrates and molybdenum (Mo) substrates. In each category we also examined coatings with a pre-coat of Mo between the substrate and the HR stack. The improved dielectric HR stacks effectively shielded the Mo from the laser irradiation so that the thresholds of virtually all Mo samples exceeded levels of the best dielectric-enhanced and dielectric-HR-coated metal mirrors we have tested to date. In addition to the low PRF measurements, we also conducted 1064-nm damage tests at 6-kHz PRF using 65-ns pulses from the Kilroy damage test facility. The coatings survived thermal loading of fluences ranging from 2 to 10 J/cm{sup …

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will be the first production facility in the United States for the immobilization of high-level nuclear waste. Production of DWPF canistered wasteforms will begin prior to repository licensing, so decisions on facility startup will have to be made before the final decisions on repository design are made. The Department of Energy's Office of Civilian Radioactive Waste Management (RW) has addressed this discrepancy by defining a Waste Acceptance Process. This process provides assurance that the borosilicate-glass wasteform, in a stainless-steel canister, produced by the DWPF will be acceptable for permanent storage in a federal repository. As part of this process, detailed technical specifications have been developed for the DWPF product. SRS has developed detailed strategies for demonstrating compliance with each of the Waste Acceptance Process specifications. An important part of the compliance is the testing which will be carried out in the DWPF. In this paper, the bases for each of the tests to be performed in the DWPF to establish compliance with the specifications are described, and the tests are detailed. The results of initial tests relating to characterization of sealed canisters are reported.

The basis for the study of the evolution of a shocked interface stems from the question of the Rayleigh-Taylor (RT) instability (Taylor 1950). Starting in the late 18th century, the stability of an interface submitted to gravitational forces was investigated for the case in which the density of one of the materials across the interface was negligible compared to the other. Taylor analyzed the case in which the Atwood number (ratio of the difference of the densities to their sum) is less than 1, and the acceleration of the system is constant. He determined that the interface was unstable to small perturbations only if the direction of the acceleration normal to the interface coincides with that of the density gradient. Richtmyer (1960) extended Taylor's analysis to the case of an implusive acceleration. His results implied that the interface would be unstable irrespective of the relative orientation of the velocity impulse and the density gradient. His predictions were verified experimentally by Meshkov (1969), and the Richtmyer-Meshkov (RM) instability became a subject of research in its own right. Experimental, numerical, and theoretical works address this problem. The RM problem has been studied with both the shock-tube and laser experiments. In this paper, …

The third hypervariable domain of the HIV-1 gp120 envelope protein (V3) has been the focus of intensive sequencing efforts. To date, nearly one thousand V3 loop sequences have been stored in the HIV sequence database. Studies have revealed that the V3 loop elicits potent type-specific immune responses, and that it plays a significant role in cell tropism and fusion . The immunogenic tip of the loop can serve as a type-specific neutralizing antibody epitope, as well as a cytotoxic T-cell epitope. A helper T-cell epitope that lies within the amino terminal half of the V3 loop has also been characterized. Despite the richness of the immunologic response to this region, its potential for variation makes it an elusive target for vaccine design. Analyses of sibling sequence sets (sets of viral sequences derived from one person) show that multiple forms of the immunogenic tip of the loop are found within most HIV-1 infected individuals. Viral V3 sequences obtained from epidemiologically unlinked individuals from North America and Europe show extensive variation. However, some amino acid positions distributed throughout the V3 loop are highly conserved, and there is also conservation of the charge class of amino acid able to occupy certain positions relative …

Recent experiments at Sandia National Laboratories conducted in conjunction with MODEC Corporation have demonstrated successful clean- up of contaminated water in a supercritical water reactor. These experiments targeted wastes of interest to Department of Energy production facilities. In this paper we present modeling and experimental results for a surrogate waste containing 98% water, 2% methanol, and parts per million of chlorinated hydrocarbons and laser dyes. Our initial modeling results consider only methanol and water. Experimental data are available for inlet and outlet conditions and axial temperature profiles along the outside reactor wall. The purpose of our model is to study the chemical and physical processes inside the reactor. We are particularly interested in the parameters that control the location of the reaction zone. The laboratory-scale reactor operates at 25 MPa., between 300 K and 900 K; it is modeled as a plug-flow reactor with a specified temperature profile. We use Chemkin Real-Gas to calculate mixture density, with the Peng-Robinson equation of state. The elementary reaction set for methanol oxidation and reactions of other C{sub 1} and C{sub 2} hydrocarbons is based on previous models for gas-phase kinetics. Results from our calculations show that the methanol is 99.9% destroyed at 1/3 …

Searches for the top quark in p{bar p} collisions at {radical}s = 1.8 TeV are described. The analyses are based on data with an integrated luminosity of 4.4 pb{sup {minus}1} recorded with the Collider Detector at Fermilab in the 1988--1989 run. An upper limit on the t{bar t} cross section is obtained. The top quark with mass below 89 GeV/c{sup 2} is excluded at the 95% CL. Prospects for searches for the top quark in the future are presented. We also briefly present results on searches for supersymmetric particles. 14 refs., 10 figs.

Multilayer HfO{sub 2}/SiO{sub 2} high reflectors (HR) and polarizers show a permanent increase in their 1064-nm damage thresholds following laser conditioning at subthreshold fluences. Threshold increases of 2--3x are typical. In an effort to better understand the conditioning effect we have made laser conditioning and electronic property measurements on single layers of these two materials. The laser damage threshold of 1-{mu}m thick e-beam deposited SiO{sub 2} was increased by laser conditioning for wavelengths ranging from 355 to 1046 nm. The damage threshold of HfO{sub 2} single layers was not influenced by sub-threshold illumination. As-deposited thin films of a-SiO{sub 2} are known to contain paramagnetic electronic defects. We have used electron paramagnetic resonance (EPR) to study the concentrations and types of defects present in single layer and multilayer films of HfO{sub 2} and SiO{sub 2}. E{prime} and oxygen hole centers with concentrations on the order of 10{sup 17}/cm{sup 3} have been measured in the SiO{sub 2} layers. A previously unreported defect has been observed for HfO{sub 2}. The concentration of defects was studied both before and after laser conditioning and damage with 1064-nm photons. These electronic structure measurements are discussed in relation to an electronic defect model for laser conditioning of …

Multilayer dielectric optical coatings produced by high temperature plasma-assisted chemical vapor deposition (PCVD) have been previously shown to have very high surface and bulk damage thresholds (above 40J/cm{sup 2}). Because these experimental coatings are deposited on tubular substrates, conventional wavelength scanning cannot accurately measure the coating peak reflectance and bandwidth. Measurement of the variation of transmittance with incidence angle at fixed wavelength permits analysis of the coating spectral response. The results indicate that the PCVD coatings behave as nearly ideal'' rugate filters. Their optical performance agrees well with that predicted for a rugate by Southwell's coupled-wave theory and by the characteristic-matrix model. These 1000-layer-pair filters have maximum reflectances exceeding 99.9%, peak reflectance wavelengths within 0.5% of the design wavelength, and FWHM bandwidths narrower than 10 nm. Minor perturbations to the ideal rugate sinusoidal profile do not appreciably affect the coating optical performance. Comparison with calculations suggest that the only significant deviation of the PCVD structure from that of an ideal rugate is a small (0.7%) drift in the index period. Excellent optical performance and high damage resistance makes PCVD rugate coatings potentially useful for several high power laser applications. 13 refs., 7 figs.

During October and November, 1991, the NATO Research Vessel Alliance sailed from Amsterdam into the western Mediterranean Sea and during this time measurements were made for the validation of ATSR data. This document reports the initial comparison between ATSR measurements and sea-surface temperatures (SSTs) taken along the ship's track by an in situ thermometer at a depth of about 3m.

Research on Inertial Confinement Fusion (ICF) has progressed rapidly in the past several years. As a consequence, LLNL is developing plans to upgrade the current 120 kJ solid state (Nd{sup +3}-phosphate glass) Nova laser to a 1.5 to 2 megajoule system with the goal of achieving fusion ignition. The design of the planned Nova Upgrade is briefly discussed. Because of recent improvements in the damage resistance of optical materials it is now technically and economically feasible to build a megajoule-class solid state laser. Specifically, the damage threshold of Nd{sup +3}-doped phosphate laser glass, multilayer dielectric coatings, and non-linear optical crystals (e.g., KDP) have been dramatically improved. These materials now meet the fluence requirements for a 1.5--2 MJ Nd{sup 3+}-glass laser operating at 1054 and 351 nm and at a pulse length of 3 ns. The recent improvements in damage thresholds are reviewed; threshold data at both 1064 and 355 nm and the measured pulse length scaling are presented. 20 refs., 9 figs., 2 tabs.

The Department of Energy (DOE) has several facilities that either generate and/or store transuranic (TRU)-waste from weapons program research and production. Much of this waste also contains hazardous waste constituents as regulated under Subtitle C of the Resource Conservation and Recovery Act (RCRA). Toxicity characteristic metals in the waste principally include lead, occurring in leaded rubber gloves and shielding. Other RCRA metals may occur as contaminants in pyrochemical salt, soil, debris, and sludge and solidified liquids, as well as in equipment resulting from decontamination and decommissioning activities. Volatile organic compounds (VOCS) contaminate many waste forms as a residue adsorbed on surfaces or occur in sludge and solidified liquids. Due to the presence of these hazardous constituents, applicable disposal regulations include land disposal restrictions established by Hazardous and Solid Waste Amendments (HSWA). The DOE plans to dispose of TRU-mixed waste from the weapons program in the Waste Isolation Pilot Plant (WIPP) by demonstrating no-migration of hazardous constituents. This paper documents the current technical basis for methodologies proposed to develop a post-closure RCRA hazardous constituent source term. For the purposes of demonstrating no-migration, the hazardous constituent source term is defined as the quantities of hazardous constituents that are available for transport after …

The Lawrence Livermore National Laboratory (LLNL) Engineering Directorate is in the third year of a diversity process that has changed the culture of the organization in many ways. This work outlines progress toward realizing the LLNL Engineering Diversity Model. Currently recommendations are being implemented that have been formulated through a problem resolution process, described in this work, in which employees helped identify problems, recommend solutions, and work with managers in focus groups. The process of arriving at the recommendations and the lessons learned through the problem resolution process are discussed. Ongoing actions, short-term goals, and long-term goals of the program are described.

The two-dimensional (R - Z) electromagnetic code FMRZ has been written to model inductive sources self-consistently in time. The code models an argon plasma with momentum-transfer, excitation and ionization as electron-neutral reactions and scattering and charge-exchange for the ion-neutral reactions. The electrons and ions are treated as Maxwellian fluid species and a reduced set of Maxwell`s equations is used to advance the electromagnetic fields. The set of equations used in FMRZ is not subject to typical numerical constraints present in many time dynamic codes allowing one to choose appropriate the and space scales to resolve only the frequencies and scale lengths of interest. The model retains nonlinear driving terms which give rise to a pondermotive force that distorts the density profile. Density and power profiles will be used to illustrate the physical effects of various terms in the equations. Trends in average density and temperature compare well with an analytic model.

The third hypervariable domain of the HIV-1 gp120 envelope protein (V3) has been the focus of intensive sequencing efforts. To date, nearly one thousand V3 loop sequences have been stored in the HIV sequence database. Studies have revealed that the V3 loop elicits potent type-specific immune responses, and that it plays a significant role in cell tropism and fusion . The immunogenic tip of the loop can serve as a type-specific neutralizing antibody epitope, as well as a cytotoxic T-cell epitope. A helper T-cell epitope that lies within the amino terminal half of the V3 loop has also been characterized. Despite the richness of the immunologic response to this region, its potential for variation makes it an elusive target for vaccine design. Analyses of sibling sequence sets (sets of viral sequences derived from one person) show that multiple forms of the immunogenic tip of the loop are found within most HIV-1 infected individuals. Viral V3 sequences obtained from epidemiologically unlinked individuals from North America and Europe show extensive variation. However, some amino acid positions distributed throughout the V3 loop are highly conserved, and there is also conservation of the charge class of amino acid able to occupy certain positions relative …

We have developed techniques and are commencing experiments using enriched {sup 41}Ca as a tracer in isolated rabbit heart preparations. The aims of the study are to measure calcium uptake and deposition in response to cardiac ischemia and reperfusion, and to investigate events and mechanism leading to irreversible myocyte injury.

Twenty one hundred metric tons of spent nuclear fuel are stored in two concrete pools on the Hanford Site, known as the K Basins, near the Columbia River. The deteriorating conditions of the fuel and the basins provide engineering and management challenges to assure safe current and future storage. DE and S Hanford, Inc., part of the Fluor Daniel Hanford, Inc. lead team on the Project Hanford Management Contract, is constructing facilities and systems to move the fuel from current wet pool storage to a dry interim storage facility away from the Columbia River, and to treat and dispose of K Basins sludge, debris and water. The process starts in the K Basins where fuel elements will be removed from existing canisters, washed, and separated from sludge and scrap fuel pieces. Fuel elements will be placed in baskets and loaded into Multi-Canister Overpacks (MCOs) and into transportation casks. The MCO and cask will be transported into the Cold Vacuum Drying Facility, where free water within the MCO will be removed under vacuum at slightly elevated temperatures. The MCOs will be sealed and transported via the transport cask to the Canister Storage Building (CSB) in the 200 Area for staging prior …

The design and background data for a sodium layer laser guide star system to be installed on the 3 meter telescope at Lick Observatory is presented. A 30 W dye laser at 589 nm and 10 kHz will be mounted on the telescope and will be pumped by fiber coupled frequency doubled YAG laser located in a separate room.

The Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will be the first production facility in the United States for the immobilization of high-level nuclear waste. Production of DWPF canistered wasteforms will begin prior to repository licensing, so decisions on facility startup will have to be made before the final decisions on repository design are made. The Department of Energy`s Office of Civilian Radioactive Waste Management (RW) has addressed this discrepancy by defining a Waste Acceptance Process. This process provides assurance that the borosilicate-glass wasteform, in a stainless-steel canister, produced by the DWPF will be acceptable for permanent storage in a federal repository. As part of this process, detailed technical specifications have been developed for the DWPF product. SRS has developed detailed strategies for demonstrating compliance with each of the Waste Acceptance Process specifications. An important part of the compliance is the testing which will be carried out in the DWPF. In this paper, the bases for each of the tests to be performed in the DWPF to establish compliance with the specifications are described, and the tests are detailed. The results of initial tests relating to characterization of sealed canisters are reported.

The Nijmegen YN potential models are reviewed. Differences with the models constructed by the Juelich group are highlighted. A mini- review is given of the status of the scalar mesons and their relevance for the NN and YN interactions. Finally, the reactions {bar N}N {yields} {bar Y}Y are discussed.

It is popular to use multiresolution systems for image coding and compression. However, general-purpose techniques such as filter banks and wavelets are linear. While these systems are rigorous, nonlinear features in the signals cannot be utilized in a single entity for compression. Linear filters are known to blur the edges. Thus, the low-resolution images are typically blurred, carrying little information. We propose and demonstrate that edge-preserving filters such as median filters can be used in generating a multiresolution system using the Laplacian pyramid. The signals in the detail images are small and localized to the edge areas. Principal component vector quantization (PCVQ) is used to encode the detail images. PCVQ is a tree-structured VQ which allows fast codebook design and encoding/decoding. In encoding, the quantization error at each level is fed back through the pyramid to the previous level so that ultimately all the error is confined to the first level. With simple coding methods, we demonstrate that images with PSNR 33 dB can be obtained at 0.66 bpp without the use of entropy coding. When the rate is decreased to 0.25 bpp, the PSNR of 30 dB can still be achieved. Combined with an earlier result, our work demonstrate …