This report lists and briefly describes {approx}50 critical and {approx}20 subcritical experiments with unreflected and unmoderated uranium (93.2 wt% {sup 235}U) metal that could easily be incorporated into the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Photographs of several assemblies are included.

During the year February 1, 1998 to January 31, 1999, the authors accomplished the following: (1) the authors published their research results for paleoclimate modeling and the use of data to check the model results; (2) the authors participated in the BIOME 6000 project to produce paleovegetaion maps for 6000 and 21,000 years ago and published the results; (3) the authors continued their involvement in the PMIP(Paleoclimate Modeling Intercomparison Project) and contributed to an overview paper describing the 6 ka African monsoon response of 18 models and to a comparison of simulated biomes at 6 ka from ten models; (4) the authors contributed to the development of earth system component models and coupling strategies; (5) the authors explored a wide range of interactions among the earth's atmosphere, ocean and land surface in the context of past, present and future climates; (6) the authors developed and applied techniques for data-model comparisons; (7) the authors developed and used tools for model diagnostics and model intercomparisons; and (8) the authors began modeling ENSO variability during the last 20,000 years. By using data-constructed ''benchmarks'' for coupled models, the authors demonstrated that the deployment of models that include an increasingly wide spectrum of feedbacks leads …

SRTC has completed filtration testing of tetraphenylborate (TPB) slurries with and without sludge. These tests were slightly different from previous SRS tests in that they used continuous mode concentration and constant volume washing evolutions. The extent of TPB recovery during washing was measured. The resulting washed precipitate slurry, with sludge, was stored at ambient temperature and under a nitrogen-inerted atmosphere to study TPB stability. Samples of both unwashed and washed slurries were submitted for rheology measurements.

This study examined the ion exchange capacity of crystalline silicotitanate in a simulated waste solution. The focus areas included the effect of temperature and radiation on cesium sorption capacity. The cesium is expected to be removed from high-level radioactive wastes using these ion exchange materials.

Filamentation, and consequently output beam quality in InGaN quantum-well lasers are found to be strong functions of quantum-well width because of the interplay of quantum-confined Stark effect and many-body interactions. For an In{sub 0.2}Ga{sub 0.8}N/GaN gain medium the antiguiding factor in a thick 4nm quantum well is considerably smaller than that for a narrow 2nm one. As a result, lasers with the thicker quantum well maintain fundamental-mode operation with wider stripe widths and at significantly higher excitation levels.

The safety impact of experimentally observed N Reactor fuel sample fracture and fragmentation is evaluated using an average reaction rate enhancement derived from data from thermo-gravimetric analysis (TGA) experiments on fuel samples. The enhanced reaction rates attributed to fragmentation were within the existing safety basis.

We report on the metal-organic chemical vapor deposition (MOCVD) of strained layer superlattices (SLSs) of InAsSb/InAs/InPSb/InAs as well as mid-infrared optically pumped lasers grown using a high speed rotating disk react,or (RDR). The devices contain AIAsSb cladding layers and strained, type I, InAsSb/InAs/InPSb/InAs strained layer superlattice (SLS) active regions. By changing the layer thickness and composition of the SLS, we have prepared structures with low temperature (<20K) photoluminescence wavelengths ranging from 3.4 to 4.8 pm. The optical properties of the InAsSb/InPSb superlattices revealed an anomalous low energy transition that can be assigned to an antimony-rich, interfacial layer in the superlattice. This low energy transition can be eliminated by introducing a 1.0 nm InAs layer between the InAsSb and InPSb layers in the superlattice. An InAsSb/InAs/lnPSbflnAs SLS laser was grown on an InAs substrate with AlAs{sub 0.16}Sb{sub 0.84} cladding layers. A lasing threshold and spectrally narrowed laser emission were seen from 80 through 250 K, the maximum temperature where lasing occurred. The temperature dependence of the SLS laser threshold is described by a characteristic temperature, T{sub 0} = 39 K, from 80 to 200 K.

We report the growth of InSb on GaAs using InAlSb buffers of high interest for magnetic field sensors. We have grown samples by metal-organic chemical vapor deposition consisting of {approx}0.55{micro}m thick InSb layers with resistive InAlSb buffers on GaAs substrates with measured electron mobilities of {approx}40,000 cm{sup 2}/V.s. We have investigated the In{sub 1-x}Al{sub x}Sb buffers for compositions x {le} 0.22 and have found that the best results are obtained near x = 0.12 due to the tradeoff of buffer layer bandgap and lattice mismatch.

This report summarizes the pilot-scale research requested by the salt disposition team to examine the effect of crystalline silicotitanate (CST) resin with adsorbed noble metals on the maximum hydrogen generation rate produced during the DWPF melter feed preparation processes.

The main objective of these scoping tests was to measure the rate of hydrogen generation in a series of experiments designed to duplicate the expected SRAT and SME processing conditions in laboratory scale vessels. This document details the testing performed to determine the maximum hydrogen generation expected with a coupled flowsheet of sludge, loaded CST [crystalline silicotitanate], and frit.

The dispersion of tetraphenylborate in continuous stirred tank reactors plays a significant role in the utility achieved from the tetraphenylborate. Investigating idealized mixing of the materials can illuminate how this dispersion occurs.

Toyota's introduction of a hybrid electric vehicle (HEV) named ''Prius'' in Japan and Honda's proposed introduction of an HEV in the United States have generated considerable interest in the long-term viability of such fuel-efficient vehicles. A performance and cost projection model developed entirely at Argonne National Laboratory (ANL) is used here to estimate costs. ANL staff developed fuel economy estimates by extending conventional vehicle (CV) modeling done primarily under the National Cooperative Highway Research Program. Together, these estimates are employed to analyze dollar costs vs. benefits of two of many possible HEV technologies. We project incremental costs and fuel savings for a Prius-type low-performance hybrid (14.3 seconds zero to 60 mph acceleration, 260 time) and a higher-performance ''mild'' hybrid vehicle, or MHV (11 seconds 260 time). Each HEV is compared to a U.S. Toyota Corolla with automatic transmission (11 seconds 260 time). The base incremental retail price range, projected a decade hence, is $3,200-$3,750, before considering battery replacement cost. Historical data are analyzed to evaluate the effect of fuel price on consumer preferences for vehicle fuel economy, performance, and size. The relationship between fuel price, the level of change in fuel price, and consumer attitude toward higher fuel efficiency is …

Fundamental physics issues facing development of fusion power on a small-scale are assessed with emphasis on the idea of Inertial Electrostatic Confinement (IEC). The authors propose a new concept of accelerator-driven IEC fusion, termed Converging Beam Inertial Electrostatic Confinement (CB-IEC). CB-IEC offers a number of innovative features that make it an attractive pathway toward resolving fundamental physics issues and assessing the ultimate viability of the IEC concept for power generation.

Sample 203KWBMF was taken from the K West Sandfilter Backwash Pit on November 4, 1999 and received by 2224 Laboratory on November 4, 1999. Analyses were performed on sample 203KWBMF in accordance with ''Letter of Instruction for K Basins sandfilter Backwash Line Samples'' (LOI) in support of the K Basin Sandfilter Backwash Line Characterization Project.

Laser-plasma interaction physics is studied in the context of laser fusion using the six-beam laser facility at LULI. Interaction between RPP laser beams and well-characterized preformed plasmas has been performed to study various aspects of stimulated Brillouin and Raman scattering (SBS and SRS), self-focusing and filamentation. Thomson scattering of a short wavelength probe laser beam was used to provide a complete characterization of the plasma (electron temperature, density, flow velocity) and measurements of the density fluctuations associated with ion acoustic waves and electron plasma waves, with temporal, spatial, frequency and wavenumber resolution. Among the different studies, they will present results on the effect of polarization smoothing, target material, multi-species plasmas, and Langmuir decay on parametric instabilities.

Important factors in the application of sensing technology to space applications are low mass, small size, and low power. All of these attributes are enabled by the application of MEMS and micro-fabrication technology to microsensors. Two types of sensors are utilized in space applications: remotes sensing from orbit around the earth or another planetary body, and point sensing in the spacecraft or external to it. Several Sandia projects that apply microfabrication technologies to the development of new sensing capabilities having the potential for space applications will be briefly described. The Micro-Navigator is a project to develop a MEMS-based device to measure acceleration and rotation in all three axes for local area navigation. The Polychromator project is a joint project with Honeywell and MIT to develop an electrically programmable diffraction grating that can be programmed to synthesize the spectra of molecules. This grating will be used as the reference cell in a gas correlation radiometer to enable remote chemical detection of most chemical species. Another area of research where microfabrication is having a large impact is the development of a lab on a chip. Sandia's efforts to develop the {mu}ChemLab{trademark} will be described including the development of microfabricated pre-concentrators, chromatographic columns, …

Neutron activation of aluminum may occur by several neutron capture reactions. Four such reactions are described here: {sup 27}Al + n = {sup 28}Al, {sup 27}Al(n,{alpha}){sup 24}Na, {sup 27}Al(n, 2n){sup 26}Al and {sup 27}Al(n,p){sup 27}Mg. The radioactive nuclei {sup 28}Al, {sup 24}Na, and {sup 27}Mg, which are produced via the {sup 27}Al + n = {sup 28}Al, {sup 27}Al(n,{alpha}){sup 24}Na and {sup 27}Al(n,p){sup 27}Mg neutron reactions, beta decay to excited states of {sup 28}Si, {sup 24}Mg and {sup 27}Al respectively. These excited states then emit gamma rays as the nuclei de-excite to their respective ground states.

An experiment is described where the two products of the Langmuir Decay Instability (LDI) of a primary electron plasma wave have been observed and identified without any ambiguity. Primary Langmuir waves are driven by Stimulated Raman Scattering (SRS) of an incident laser which provides well-defined electron plasma waves. Thomson scattering of a short wavelength probe beam yields measurements of the amplitude of the waves resolved in time, space, wavelength and wavevector, that allow identification of the probed waves.

This paper describes the model and method used to obtain the periodically estimated uncertainties for measurement of the scattering parameters S{sub 11} and S{sub 22} on a Vector Network Analyzer (VNA). A thru-reflect-line (TRL) method is employed as a second tier calibration to obtain uncertainty estimates using an NIST-calibrated standard. An example of tabulated listings of these uncertainty estimates is presented and the uncertainties obtained for a VNA with 7 mm, 3.5 mm, and type N coaxial interfaces used in the laboratory over several years are summarized.

Testing examined the extent and rate of strontium, plutonium, uranium, and neptunium removal from radioactive waste solutions at 4.5M and 7.5M in Na concentration by adsorption onto monosodium titanate (MST) at 0.2 g/L. Results indicate that the extents and rates of strontium, plutonium, and neptunium removal in radioactive waste solutions agree well with those previously measured using simulated waste solutions. Uranium removal in the 7.5M Na radioactive waste solution proved similar to that observed with simulated waste solutions. Uranium removal in the 4.5M Na radioactive waste solution proved lower than expected from previous simulant tests. The authors conclude that MST adsorption data obtained from simulated waste solutions provide reliable predictions for use in facility design and flowsheet modeling studies in the Salt Disposition Alternatives program.

This report is a continuation of our assessment of the finishing of low thermal expansion material wafers obtained through three different commercial pathways. This quarter we have patterned and printed a ULE{reg_sign} wafer (Rodel 1) and saw no difference between its images and those from silicon wafer substrates. This further demonstrated that ULE{reg_sign} can be used as the EUVL mask substrate material. We have also evaluated substrates produced by three vendors: Hoya, General Optics, and Rodel. Consistent with our results reported last quarter, surface roughness of the bare substrates from all three companies does not depend on the position. For Hoya, the wafers it produced had a low roughness than those from last quarter. However, the cleanliness of the wafers needs to be improved. For General Optics, the wafer roughness has increased, and it was only able to deliver one wafer this quarter. General Optics will be replaced by Schott ML next quarter. For Rodel, one of its wafers (Rodel 1) that had been cleaned in-house showed excellent finishing and was selected to be patterned. We also observed that the sleeks on the substrates were smoothed by the ML coating. The other two Rodel wafers (Rodel 2 and Rodel 4) …

The primary focus of the current study is to determine allowable loadings of feed streams containing different ratios of plutonium, uranium, and minor components into the LaBS glass and to evaluate thermal stability with respect to the DWPF pour.

High resolution measurements of spectrally resolved cathodoluminescence (CL) decay have been made in several commercial and experimental phosphors doped with Eu and Tb at beam energies ranging from 0.8 to 4 keV. CL emission from the lowest two excited states of both rare earth activators was compared to the decay of photoluminescence (PL) after pulsed laser excitation. We find that, at long times after the cessation of electron excitation, the CL decay rates are comparable to those measured in PL, at short times, the decay process is considerably faster and has a noticeable dependence on the energy of the electron beam. These beam energy effects are largest for the higher excited states and for phosphors with larger activator concentrations. Measurements of the experimental phosphors over a range of activator fractions from 0.1 to 0.002 show that the beam energy dependence of the steady-state CL efficiency is larger for higher excited states and weakens as the activator concentration is reduced. The latter effect is strongest for Y{sub 2}SiO{sub 5}:Tb, but also quite evident in Y{sub 2}O{sub 3}:Eu. We suggest that the electron beam dependence of both the decay lifetimes and the steady state CL efficiency may be due to interaction of …

This report contains analytical data for samples taken during Third Quarter 1999 from wells of the LFW series located at the Sanitary Landfill at the Savannah River Site. The data are submitted in reference to the Sanitary Landfill Operating Permit. The report presents monitoring results that equaled or exceeded the Safe Drinking Water Act final Primary Drinking Water Standards or screening levels, established by the U.S. Environmental Protection Agency, the South Carolina final Primary Drinking Water Standard for lead, or the SRS flagging criteria.