The practical effects of blistering and flaking in neutral injection systems are studied. These effects will soon be more important because of energy increases in systems now under development and because of their operation with fast helium ions as well as hydrogen and deuterium ions. Two main effects were studied: enhanced erosion rate and possible voltage breakdown from sharp flakes and gas emission.

In order for computation to emerge spontaneously and become an important factor in the dynamics of a system, the material substrate must support the primitive functions required for computation: the transmission, storage, and modification of information. Under what conditions might we expect physical systems to support such computational primitives This paper presents research on Cellular Automata which suggests that the optimal conditions for the support of information transmission, storage, and modification, are achieved in the vicinity of a phase transition. We observe surprising similarities between the behaviors of computations and systems near phase-transitions, finding analogs of computational complexity classes and the Halting problem within the phenomenology of phase-transitions. We conclude that there is a fundamental connection between computation and phase-transitions, and discuss some of the implications for our understanding of nature if such a connection is borne out. 31 refs., 16 figs.

The accuracy of a numerical method for solving the neutron transport equation is limited by the smallest mean free path in the problem. Since problems in the asymptotic diffusive regimes have vanishingly small mean free paths, it seems hopeless, given a limited amount of computer memory, that an accurate solution can be obtained for these problems. However we found that the accuracy of a numerical method improves as the scattering ratio increases with the total cross section and the grid spacing held fixed for problems that are in the asymptotic diffusive regime. This phenomenon is independent of the numerical method and can be explained on physical grounds. The numerical results by the Diamond Difference Method are given to show this phenomenon.

This issue of Science and Technology Review has the following articles: (1) Enhanced National Security through International Research Collaborations--Commentary by Stephen G. Cochran; (2) Building Networks of Trust through Collaborative Science--Livermore scientists are leading collaborative science and technology projects with colleagues from Central and South Asia and the Middle East; (3) Tracing the Steps in Nuclear Material Trafficking--The Laboratory.s nuclear science expertise is helping to thwart the illicit trafficking of nuclear material; (4) Looking at Earth in Action--Geophysicists at Livermore are using laboratory experiments to examine such issues as how best to store nuclear wastes and how to mitigate the effects of greenhouse gases; and (5) Gamma-Ray Bursts Shower the Universe with Metals--Computer models indicate that gamma-ray bursts from dying stars may be important sources of elements such as iron, zinc, titanium, and copper.

We have conducted an experiment in which the temperature and the wavelength dependent emissivity of a shocked surface has been measured. In the past, only the thermal emission from the shocked surface has been measured. The lack of knowledge of the emissivity as a function of wavelength leads to uncertainty in converting the measured emission spectrum into a surface temperature. We have developed a technique by which we are able to calculate both the emissivity of the shocked surface over a range of relevant wavelengths and the temperature of the surface. We use a multi-channel spectrometer in combination with a pulsed light source having a known spectrum of infrared radiation. Two separate techniques using a pulse of reflected radiation are employed and described. Both give the same result: An initially polished molybdenum surface that is shocked and partially released has a temperature of 1040 degrees Kelvin and a wavelength ({lambda}) dependent emissivity of 0.16 ({lambda}=1.2{micro}m), 0.10 ({lambda} =1.6 {micro}m), and 0.20 ({lambda} =2.3 {micro}m).

Recently, new cross section measurements by the GEANIE collaboration have been published for {sup 239}Pu(n, 2n{gamma}) [Ber00] and {sup 235}U(n, 2n{gamma}) [You00] from threshold to 20 MeV. When combined with nuclear reaction calculations [Che00, Cha99, Cha01], these measurements provide the most accurate information available on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section for incident neutron energies, E{sub n} {approx}< 14 MeV. This new data has prompted a re-evaluation of the {sup 239}Pu(n, 2n) {sup 238}Pu reaction cross section considering all available experimental data. The data prior to the measurement of Bernstein et al. [Ber00] is illustrated in Figure 1a. These data sets were considered by previous evaluations [ENDL] of the {sup 239}Pu(n, 2n) cross section. The most precise experiment was an activation measurement done by Lougheed et al. [Lou00] for incident neutron energies, E{sub n}, between 13-15 MeV. In addition, there were two neutron-counting experiments, one by Mather et al. [Mat72] and one by Frehaut et al. [Fre85]. These two measurements cover a wide incident neutron range, with data points from threshold to E{sub n} {approx} 14 MeV. The available data sets are in poor agreement with each other and in some cases do not meet …

An alternative approach is described to evaluate the statistical nature of the breakup of shaped charge liners. Experimental data from ductile and brittle copper jets are analyzed in terms of velocity gradient, deviation of {Delta}V from linearity, R/S analysis, and the Hurst exponent within the coupled map lattice model. One-dimensional simulations containing 600 zones of equal mass and using distinctly different force-displacement curves are generated to simulate ductile and brittle behavior. A particle separates from the stretching jet when an element of material reaches the failure criterion. A simple model of a stretching rod using brittle, semi-brittle, and ductile force-displacement curves is in agreement with the experimental results for the Hurst exponent and the phase portraits and indicates that breakup is a correlated phenomenon.

A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.

Disclosed is a locking mechanism for an indexing spindle. A conventional spur gear having outwardly extending teeth is affixed to the spindle. Also included is a rotatably mounted camshaft whose axis is arranged in skewed relationship with the axis of the spindle. A disk-like wedge having opposing camming surfaces is eccentrically mounted on the camshaft. As the camshaft is rotated, the camming surfaces of the disk are interposed between adjacent gear teeth with a wiping action that wedges the disk between the gear teeth. A zero backlash engagement between disk and gear results, with the engagement having a high mechanical advantage so as to effectively lock the spindle against bi-directional rotation.

The Lawrence Livermore Laboratory seismic net was upgraded by installing two horizontal seismometers at each of the four LLL stations. These seismometers record radial and transverse ground motion from underground nuclear explosions at the Nevada Test Site and complement the vertical components which were installed several years ago. Each station now monitors three orthogonal components of ground velocity over a broad frequency band.

Worldwide data on terrorist incidents between 1968 and 2004 gathered by the RAND corporation and the Oklahoma City National Memorial Institute for the Prevention of Terrorism (MIPT) were assessed for patterns and trends in morbidity/mortality. The data involve a total of 19,828 events, 7,401 ''adverse'' events (each causing {ge}1 victim), 91,346 cases of casualty (either injury or death) and 25,408 deaths. Analyses revealed a number of interesting patterns and apparently significant trends. Most terror-related adverse events, casualties and deaths involved bombs and guns. Weapon-specific patterns and terror-related risk levels in Israel (ISR) have differed markedly from those of all other regions combined (AOR). ISR had a fatal fraction of casualties about half that of AOR, but has experienced relatively constant lifetime terror-related casualty risks on the order of 0.5%--a level 2 to 3 orders of magnitude more than those experienced in AOR, which have increased {approx}100-fold over the same period. Individual event fatality has increased steadily, the median increasing from 14 to 50%. Lorenz curves obtained indicate substantial dispersion among victim/event rates: about half of all victims were caused by the top 2% (10%) of harm-ranked events in OAR (ISR). Extreme values of victim/event rates were found to be well …

Measurements of bomb-pulse {sup 36}Cl and chloride concentrations in soils from the Pit 7 Complex basin, LLNL Site 300, combined with a demonstration model of moisture flux and infiltration rate, indicate that the bomb-pulse can be an extremely useful tool for the characterization of the unsaturated hydrology at Site 300. Bomb-pulse {sup 36}Cl is readily identifiable in the soil column, and exhibits moisture infiltration-related variations at different locations. It can be used to calibrate chloride accumulation models of unsaturated flow. In the continuing investigation of the origin and development of the Pit 7 Complex tritium plume, bomb-pulse {sup 36}Cl will provide a useful mechanism for hydrologic characterization.

Activities for this first quarter include continued effort in simulating the experiments performed in the NASA 7-ft x 10-ft wind tunnel with the GTS geometry using both LLNL's advanced computational tools and NASA's Overflow code. Along with this analysis effort, we continue to implement advanced algorithms in LLNL's models to improve simulation speed and accuracy and to verify and validate these advanced simulation tools.

None

Advances in computational capability and modeling techniques, as well as improvements in experimental characterization methods offer the possibility of directly comparing modeling and experiment investigations of irradiation effects in metals. As part of a collaboration among the Instituto de Fusion Nuclear (DENIM), Lawrence Livermore National Laboratory (LLNL) and CIEMAT, single and polycrystalline {alpha}-Fe samples have been irradiated with 150 keV Fe-ions to doses up to several dpa. The irradiated microstructure is to be examined with both transmission electron microscopy (TEM) and positron annihilation spectroscopy (PAS). Concurrently, we have modeled the damage accumulation in Fe under these irradiation conditions using a combination of molecular dynamics (MD) and kinetic Monte Carlo (KMC). We aim to make direct comparison between the simulation results and the experiments by simulating TEM images and estimating positron lifetimes for the predicted microstructures. While the identity of the matrix defect features cannot be determined from TEM observations alone, we propose that both large self-interstitial loops, trapped at impurities within the material, and small, spherical nanovoids form.

This report gives the weekly progress for the B, D, and F piles. The report also gives a brief discussion of the following activities: process water control and pressure drop studies; purging of D, B, and F piles; slug corrosion studies; tube corrosion studies; thimble corrosion studies; and graphite expansion studies.

The focal length of the spatial filter and final focus lenses for the National Ignition Facility are measured to < {+-} 0.01% using a combination of master lenses and production-oriented techniques for relative focal length.

Neutron hardening and embrittlement of pressure vessel steels is due to a high density of nanometer scale features, including Cu-rich precipitates which form as a result of radiation enhanced diffusion. High-energy displacement cascades generate large numbers of both isolated point defects and clusters of vacancies and interstitials. The subsequent clustering, diffusion and ultimate annihilation of primary damage is inherently coupled with solute transport and hence, the overall chemical and microstructural evolutions under irradiation. In this work, we present atomistic simulation results, based on many-body interatomic potentials, of the migration of vacancies, solute and self-interstitial atoms (SIA) in pure Fe and binary Fe-0.9 and 1.0 at.% Cu alloys. Cu diffusion occurs by a vacancy mechanism and the calculated Cu diffusivity is in good agreement with experimental data. Strain field interactions between the oversized substitutional Cu solute atoms and SIA and SIA clusters are predominantly repulsive and result in both a decreased activation energy and diffusion pre-factor for SIA and small (N < 5) SIA cluster migration, which occurs by three-dimensional motion. The Cu appears to enhance the reorientation of the SIA clusters to different <111> directions, as well as the transition from <110> to mobile <111> configurations. The migration behavior of …

The Hanford Site Groundwater Monitoring Project at Pacific Northwest National Laboratory (PNNL) investigated selected isotopic signature techniques to aid interpretation of contaminant plumes in Hanford Site groundwater. The main approach was to select groundwater samples expected to exhibit a variety of contaminant characteristics and then develop inductively coupled plasma mass spectrometry (ICP-MS) analytical methods for the groundwater matrix. Initial broad scans were used to identify interferences and to focus the method development on isotopes showing the greatest promise of practical application. In addition, earlier work characterizing chlorine-36 in Hanford Site groundwater by accelerator mass spectrometry (AMS) will be discussed.

Science and engineering doctoral students performing energy related research were supported by a USDOE/ESPCoR Traineeship grant awarded to the Kentucky EPSCoR Committee. The grant, administered by the KY DOE/EPSCoR Subcommittee, focused on research having the general description of {open_quotes}Clean Uses of Fossil Fuels{close_quotes}. The value of the grant was $500,000 for three years duration, beginning September 30, 1991 and ending September 29, 1994. Ten PhD students were selected for support during the first year of the Traineeship. Upon reviewing coursework and research progress of the students at the end of the first year, the KY DOE/EPSCoR Subcommittee awarded a second year of support at the same $25,000/year funding level. A total of 12 students will have been supported during the duration of the grant as a consequence of one student completing his degree during the support period and of one student deciding that she wanted to complete only a Masters rather than a PhD degree. The students supported were at either the University of Kentucky or the University of Louisville - the two PhD, science and engineering granting universities within the Commonwealth of Kentucky. The disciplines of these students included Biology, Chemical Engineering, Chemistry, Geological Sciences, and Physics. The methods …

The principal objective of this research is to determine the role host petroleum-derived oils (1000{degrees}F+), as well as that of catalytically treated host oils, play when used as liquefaction solvents in coprocessing with coal. The host oils will be extensively characterized and then pretreated in a number of ways which involve catalytic reactions such as hydrogenation, hydrocracking, isomerization, and dehydrogenation. The pretreated oils will then be characterized. The effects of the host oil on coprocessing with coal will be compared to those obtained using catalytically modified heavy oils. When appropriate, model compounds will be used to study specific reactions brought about by the pretreatments. Highly dispersed iron catalysts modified by the addition of small amounts of other metals will be used to modify the chemical composition of the host oils. To date, five different pretreatment reactions have been carried out on the Amoco oil. Table 1 list some properties of this oil. Details of the reaction conditions used are given in Table 2. An objective of the pretreatment reactions is to increase hydrogen content without too significant a breakdown (cracking) of the hydrocarbon structures. Severe cracking could produce a light hydrocarbon solvent which may not be suitable for coprocessing because …

None

The objective of the test discussed in this report is to verify further the corrosion rate of irradiated tubular fuel elements under conditions of high specific power and central core temperatures. The fuel will be the inner component of an NPR fuel element assembly. A proposal to charge two tubular fuel elements into the GEH-P7 Loop has been made. The upper fuel element of the two has been irradiated to 1660 MWD/T in a Hanford reactor. A hydraulic cylinder will be attached to the upper fuel element. The hydraulic cylinder will be used to move a chisel along the outer surface of the upper fuel element and shear off a cap which has been welded over a hole through the cladding. The lower fuel element of the two will be used to add heat to the loop so that the desired loop water temperatures can be maintained.

The use of methanol (MeOH) as a fuel additive and in MTBE production has renewed interest in the search for improved MeOH processes. Commercial processes are characterized by high pressures and temperatures with low per pass conversion (10--12%). Efforts are underway to find improved MeOH synthesis processes. A slurry phase ``concurrent`` synthesis of MeOH/methyl formate (MeF) which operates under relatively mild conditions (100{degrees}C lower than present commercial processes) was the subject of investigation in this work. Evidence for a reaction scheme involving the carbonylation of MeOH to MeF followed by the hydrogenolysis of MeF to two molecules of MeOH -- the net result being the reaction of H{sub 2} with CO to give MeOH via MeF, is presented. Up to 90% per pass conversion and 98% selectivity to methanol at rates comparable to commercial processes have been obtained in spite of the presence of as much as 10,000 ppM CO{sub 2} and 3000 ppM H{sub 2}O in the gas and liquid respectively. The effect of process parameters such as temperature, pressure, H{sub 2}/CO ratio in the reactor, flow rate and catalyst loading were also investigated. The use of temperatures above 170{degrees}C at a pressure of 50 atm results in MeF …