None

Theoretical physics problems related to divertor design are presented, organized by the region in which they occur. Some of the open questions in edge physics are presented from a theoretician's point of view. After a cursory sketch of the fluid models of the edge plasma and their numerical realization, the following topics are taken up: time-dependent problems, non-axisymmetric effects, anomalous transport in the scrape-off layer, edge kinetic theory, sheath effects and boundary conditions in divertors, electric field effects, atomic and molecular data issues, impurity transport in the divertor region, poloidally localized power dissipation (MARFEs and dense gas targets), helium ash removal, and neutral transport. The report ends with a summary of selected problems of particular significance and a brief bibliography of survey articles and related conference proceedings.

This supporting document presents a description of the 242-A Evaporator flowsheet. Material balances are calculated for feed, slurry, and effluent streams based on input data for the feed stream.

In May of 1996, the US Department of Energy implemented a four-year demonstration project identified as the Hanford Tanks Initiative (HTI). The HTI mission is to minimize technical uncertainties and programmatic risks by conducting demonstrations to characterize and remove tank waste using technologies and methods that will be needed in the future to carry out tank waste remediation and tank farm closure at the Hanford Site. Included in the HTI scope is the development of retrieval performance evaluation criteria supporting readiness to close single-shell tanks in the future. A path forward that includes evaluation of closure basis alternatives has been outlined to support the development of retrieval performance evaluation criteria for the AX Farm, and eventual preparation of the SEIS for AX Farm closure. This report documents the results of the Task 4, Waste Inventory study performed to establish the best-basis inventory of waste contaminants for the AX Farm, provides a means of estimating future soil inventories, and provides data for estimating the nature and extent of contamination (radionuclide and chemical) resulting from residual tank waste subsequent to retrieval. Included in the report are a best-basis estimate of the existing radionuclide and chemical inventory in the AX Farm Tanks, an …

This research investigates the relationship between execution discipline and performance. The hypothesis has two parts: 1. Different execution disciplines exhibit different performance for different computations, and 2. These differences can be effectively predicted by heuristics. A machine model is developed that can vary its execution discipline. That is, the model can execute a given program using either the control-driven, data-driven or demand-driven execution discipline. This model is referred to as a ``variable-execution-discipline`` machine. The instruction set for the model is the Program Dependence Web (PDW). The first part of the hypothesis will be tested by simulating the execution of the machine model on a suite of computations, based on the Livermore Fortran Kernel (LFK) Test (a.k.a. the Livermore Loops), using all three execution disciplines. Heuristics are developed to predict relative performance. These heuristics predict (a) the execution time under each discipline for one iteration of each loop and (b) the number of iterations taken by that loop; then the heuristics use those predictions to develop a prediction for the execution of the entire loop. Similar calculations are performed for branch statements. The second part of the hypothesis will be tested by comparing the results of the simulated execution with the …

The computer code FLOWTRAN-TF is used to analyze hypothetical hydraulic accidents for the nuclear reactor at the Savannah River Site. During a hypothetical Large Break Loss-of-Coolant Accident (LOCA), reactor assemblies would contain a two-phase mixture of air and water which flows downward. Reactor assemblies consist of nested, ribbed annuli. Longitudinal ribs divide each annulus into four subchannels. For accident conditions, air and water can flow past ribs from one subchannel to another. For FLOWTRAN-TF to compute the size of those flows, it is necessary to know the local void fraction in the region of the rib. Measurements have previously been made of length-average void fraction in a ribbed annulus. However, no direct measurements were available of local void fraction. Due to the lack of data, a test was designed to measure local void fraction at the rib. One question addressed by the test was whether void fraction at the rib is solely a function of azimuthal-average void fraction or a function of additional variables such as pressure boundary conditions. This report provides a discussion of this test.

This document is the final report for tank 241-AP-107 grab samples. Three grab samples were collected from riser 1 on September 11, 1997. Analyses were performed on samples 7AP-97-1, 7AP-97-2 and 7AP-97-3 in accordance with the Compatibility Grab Sampling and Analysis Plan (TSAP) (Sasaki, 1997) and the Data Quality Objectives for Tank Farms Waste Compatibility Program (DQO) (Rev. 1: Fowler, 1995; Rev. 2: Mulkey and Nuier, 1997). The analytical results are presented in the data summary report (Table 1). A notification was made to East Tank Farms Operations concerning low hydroxide in the tank and a hydroxide (caustic) demand analysis was requested. The request for sample analysis (RSA) (Attachment 2) received for AP-107 indicated that the samples were polychlorinated biphenyl (PCB) suspects. Therefore, prior to performing the requested analyses, aliquots were made to perform PCB analysis in accordance with the 222-S Laboratory administrative procedure, LAP-101-100. The results of this analysis indicated that no PCBs were present at 50 ppm and analysis proceeded as non-PCB samples. The results and raw data for the PCB analysis will be included in a revision to this document. The sample breakdown diagrams (Attachment 1) are provided as a cross-reference for relating the tank farm customer …

Theoretical physics problems related to divertor design are presented, organized by the region in which they occur. Some of the open questions in edge physics are presented from a theoretician`s point of view. After a cursory sketch of the fluid models of the edge plasma and their numerical realization, the following topics are taken up: time-dependent problems, non-axisymmetric effects, anomalous transport in the scrape-off layer, edge kinetic theory, sheath effects and boundary conditions in divertors, electric field effects, atomic and molecular data issues, impurity transport in the divertor region, poloidally localized power dissipation (MARFEs and dense gas targets), helium ash removal, and neutral transport. The report ends with a summary of selected problems of particular significance and a brief bibliography of survey articles and related conference proceedings.

This report assesses the potential impact of recent Federal and state regulations for airborne toxic substances on the production and consumption of heavy fuel oils. Emissions of nickel from heavy oil production in California are considered in some detail, in conjunction with California state regulations for toxic emissions. Although the use of thermal energy from heavy crude oils could in theory be impacted by toxic air pollution regulations, recent trends towards the use of natural gas for the required extraction energy appear to provide substantial relief, in addition to reducing emissions of criteria air pollutants. However, the consumption of residual fuel oils containing toxic metals could result in higher population exposures to these substances and their attendant risks may be worthy of more detailed analysis.

Approximately 80 commercially available fluorescent organic compounds were studied as dopants in a polystyrene matrix for possible use in wavelength shifting (WLS) fibers. The goal was to find a new green- emitting WLS fiber which would outperform in light yield and decay time the currently available fiber doped with K-27. Therefore the fluorescent compounds of interest should exhibit the following spectroscopic characteristics in polystyrene: {lambda}{sub abs} = 400--450 nm,{lambda}{sub em} = 450--550 nm, {tau} = 3--7 ns and quantum efficiency of minimum 0.7. Polystyrene samples doped with different fluorescent compounds were prepared and characterized. Of all the compounds tested, only a series of coumarins exhibited the spectroscopic characteristics of interest. Radiation damage studies had to be performed on these samples in order to condusively determine if they were better candidates than K-27 for green WLS fibers. AU samples except those showing opacity or deep coloration were irradiated. They were, however, separated in two sets. Radiation damage set No. 20 was mainly formed by the coumarin derivatives. Radiation damage set No. 22 was based on the remaining samples. The irradiations were performed at the Phoenix Memorial Laboratory using a {sup 60}Co source. Both sets were exposed to a total dose of …

This report provides a comprehensive analysis of the Mississippi interior salt basin and to transfer the results effectively.

Laser modulated scattering (LMS) is introduced as a non-destructive evaluation tool for defect inspection and characterization of optical surfaces and thin film coatings. This technique is a scatter sensitive version of the well-known photothermal microscopy (PTM) technique. It allows simultaneous measurement of the DC and AC scattering signals of a probe laser beam from an optical surface. By comparison between the DC and AC scattering signals, one can differentiate absorptive defects from non-absorptive ones. This paper describes the principle of the LMS technique and the experimental setup, and illustrates examples on using LMS as a tool for nondestructive evaluation of high quality optics.

A statistics-based model is being developed to predict the laser-damage-limited lifetime of UV optical components on the NIF laser. In order to provide data for the model, laser damage experiments were performed on the Beamlet laser system at LLNL (aperture: 34 cm x 34 cm). Three prototype NIF focus lenses were exposed to 351 nm pulses (1.5 ns or 3 ns) during four experimental campaigns, each consisting of 23 to 38 pulses at NIF relevant fluences. Each lens was sol-gel AR coated and all laser exposures were performed in a vacuum environment. Through inspections of the lens before, during and after the campaigns, pulse-to-pulse damage growth rates were measured for damage initiating both on the surfaces and at bulk inclusions. Radial growth rates measured for rear surface damage was typically 10x higher than that measured in the bulk or at the front surface. No significant correlation of growth rate to precursor type was indicated. For 5 J/cm², 3 ns pulses the typical radial growth rate was nominally 20 µm/pulse. Average growth rates measured on three lenses made by two manufacturers were in good agreement. While the growth rate clearly increased with fluence, the data obtained was insufficient to quantify the …

The Laser Program at LLNL has developed automated facilities for damage testing optics up to 1 meter in diameter. The systems were developed to characterize the statistical distribution of localized damage performance across large-aperture National Ignition Facility optics. Full aperture testing is a key component of the quality assurance program for several of the optical components. The primary damage testing methods used are R:1 mapping and raster scanning. Automation of these test methods was required to meet the optics manufacturing schedule. The automated activities include control and diagnosis of the damage-test laser beam as well as detection and characterization of damage events.

A novel photothermal microscopy (PTM) is developed which uses only one laser beam, working as both the pump and the probe. The principle of this single-beam PTM is based on the detection of the second harmonic component of the laser modulated scattering (LMS) signal. This component has a linear dependence on the optical absorptance of the tested area and a quadratic dependence on the pump laser power. Using a pump laser at the wavelengths of 514.5- and 532-nm high-resolution photothermal scans are performed for polished fused silica surfaces and a HfO{sub 2}/SiO{sub 2} multilayer coatings. The results are compared with those from the traditional two-beam PTM mapping. It is demonstrated that the single-beam PTM is more user-friendly (i.e. no alignment is needed) than conventional two-beam PTM and, offers a higher spatial resolution for defect detection.

Laser-induced damage of transparent fused silica optical components by 355 nm illumination occurs primarily at surface defects produced during the grinding and polishing processes. These defects can either be surface defects or sub-surface damage.Wet etch processing in a buffered hydrogen fluoride (HF) solution has been examined as a tool for characterizing such defects. A study was conducted to understand the effects of etch depth on the damage threshold of fused silica substrates. The study used a 355 nm, 7.5 ns, 10 Hz Nd:YAG laser to damage test fused silica optics through various wet etch processing steps. Inspection of the surface quality was performed with Nomarski microscopy and Total Internal Reflection Microscopy. The damage test data and inspection results were correlated with polishing process specifics. The results show that a wet etch exposes subsurface damage while maintaining or improving the laser damage performance. The benefits of a wet etch must be evaluated for each polishing process.

None

Heavy-ion induction accelerators are being developed as fusion drivers for ICF power production in the US Inertial Fusion Energy (IFE) program, in the Office of Fusion Energy of the US Department of Energy. In addition, they represent an attractive driver option for a high-yield microfusion facility for defense research. This paper describes recent progress in induction drivers for Heavy-Ion Fusion (HIF), and plans for future work. It presents research aimed at developing drivers having reduced cost and size, specifically advanced induction linacs and recirculating induction accelerators (recirculators). The goals and design of the Elise accelerator being built at Lawrence Berkeley Laboratory (LBL), as the first stage of the ILSE (Induction Linac Systems Experiments) program, are described. Elise will accelerate, for the first time, space-charge-dominated ion beams which are of full driver scale in line-charge density and diameter. Elise will be a platform on which the critical beam manipulations of the induction approach can be explored. An experimental program at Lawrence Livermore National Laboratory (LLNL) exploring the recirculator principle on a small scale is described in some detail; it is expected that these studies will result ultimately in an operational prototype recirculating induction accelerator. In addition, other elements of the US …

The objective is to provide a comprehensive geologic analysis of the Mississippi Interior Salt Basin.

Beam gauges have been used in the last decade or so for measuring the internal azimuthal compressive coil stresses in superconducting magnets. In early model Large Hadron Collider Interaction Region (LHC IR) quadrupoles tested at Fermilab, the beam gauges indicated excessively high amounts of inner and outer coil prestress during the collaring process, inconsistent with the coil size and modulus data. In response to these measurements, a simple mechanics based quantitative understanding of different factors affecting beam gauges has been developed. A finite element model with contact elements and non-linear material behavior, confirmed with experimental results, was developed. The results indicate that a small plastic deformation of either the beam or the backing plate can cause significant errors in the measured stress values. The effect of variations in coil modulus and support boundary conditions on beam gauge performance are also discussed.

Objective is to develop producing active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to synthesize such catalysts on a large scale for process development and long-term testing in slurry bubble-column reactors. A mixed oxalate of Fe, Cu, and K was prepared; a catalyst will be prepared from this material. An evaluation run was performed on an Fe-based UCI catalyst, which was shown to produce low levels of C[sub 1] and C[sub 2] paraffins; e.g., at the end of the run, when the catalyst was converting 60% of the CO, the C[sub 1] and C[sub 2] paraffin selectivities were 4.2 and 1.0, respectively.

The computer code FLOWTRAN-TF is used to analyze hypothetical hydraulic accidents for the nuclear reactor at the Savannah River Site. During a hypothetical Large Break Loss-of-Coolant Accident (LOCA), reactor assemblies would contain a two-phase mixture of air and water which flows downward. Reactor assemblies consist of nested, ribbed annuli. Longitudinal ribs divide each annulus into four subchannels. For accident conditions, air and water can flow past ribs from one subchannel to another. For FLOWTRAN-TF to compute the size of those flows, it is necessary to know the local void fraction in the region of the rib. Measurements have previously been made of length-average void fraction in a ribbed annulus. However, no direct measurements were available of local void fraction. Due to the lack of data, a test was designed to measure local void fraction at the rib. One question addressed by the test was whether void fraction at the rib is solely a function of azimuthal-average void fraction or a function of additional variables such as pressure boundary conditions. This report provides a discussion of this test.

The project objectives are (1) to explore new silylation reagents and reaction conditions with the purpose of reducing the thickness and increasing the permeance of silica membranes, (2) to delineate mechanism and kinetics of silica deposition, (3) to measure the permeability of silica layers at different extents of deposition and (4) to mathematically model the relationship of permeability and membrane structure. Study of the literature has suggested the use of certain ultrafast silylation reagents for the purpose of achieving thinner deposit layers and, hence, increase membrane permeance. The silylation reagents available commercially are suitable for grafting only one molecule per silanol ([minus]OH) group on the solid surface. The silylation reagents needed for our purposes must contain hydrolyzable groups such that the [minus]OH groups can be regenerated and the reaction continued to build a multilayer deposit. During the reporting period we have started to explore the synthesis of silylation reagents suitable for multilayer formation. A systematic series of kinetic experiments were carried out using a thermogravimetric analysis system (TGA) to measure the reaction rate of SiCl[sub 4] with surface [minus]OH groups, the rate of H[sub 2]O with surface chloride groups and the rates of condensation reactions between two [minus]OH groups and …

Objective is to develop producing active, stable iron Fischer-Tropsch catalysts for use in slurry-phase synthesis reactors and to synthesize such catalysts on a large scale for process development and long-term testing in slurry bubble-column reactors. A mixed oxalate of Fe, Cu, and K was prepared; a catalyst will be prepared from this material. An evaluation run was performed on an Fe-based UCI catalyst, which was shown to produce low levels of C{sub 1} and C{sub 2} paraffins; e.g., at the end of the run, when the catalyst was converting 60% of the CO, the C{sub 1} and C{sub 2} paraffin selectivities were 4.2 and 1.0, respectively.