A lattice gas automata (LGA) model is described, which couples solute transport with chemical reactions at mineral surfaces and in pore networks. Chemical reactions and transport are integrated into a FHP-I LGA code as a module so that the approach is readily transportable to other codes. Diffusion in a box calculations are compared to finite element Fickian diffusion results and provide an approach to quantifying space-time ratios of the models. Chemical reactions at solid surfaces, including precipitation/dissolution, sorption, and catalytic reaction, can be examined with the model because solute diffusion and mineral surface processes are all treated explicitly. The simplicity and flexibility of the LGA approach provides the ability to study the interrelationship between fluid flow and chemical reactions in porous materials, at a level of complexity that has not previously been computationally possible. 20 refs., 8 figs.

Previous calculations of line emission were extended to higher density, lower temperature plasmas, typical of those expected in early ablative compression experiments. Emission from Ne-seeded fuel was analyzed in order to diagnose the density and temperature of the compressed core. The Stark/Doppler broadened emission profile is calculated for the H-like Ne resonance line. The observable lineshape is then obtained by time-averaging over expected density and temperature profiles and by including the effects of radiative transfer.

The performance of an idealized geothermal binary-fluid-cycle energy conversion system is shown to be a function of the temperatures of brine and working fluid leaving the heat exchanger. System power output, heat exchanger area required and initial well and heat exchanger costs are determined for counterflow, single and multi-pass parallel-counterflow exchangers. Results are presented graphically as functions of the brine and working fluid exit temperatures from the exchanger. Use of the system analysis developed is illustrated by showing quantitatively the advantage of the counterflow over the other flow arrangements considered.

Fusion is examined against the yardstick of fission technology with respect to inventories of radioactivity (and associated Biological Hazard Potentials), routine emissions, accident pathways and consequences, radioactive-waste management, and misuse of nuclear materials. Based on conceptual designs of Tokamak fusion reactors with stainless steel structure and tritium inventories of 10 kg per thermal gigawatt, the apparent advantage of fusion is 1 to 2 orders of magnitude in most indices of radiological hazards. Fusion's advantage is 2 to 5 orders of magnitude in comparing damage potential of intentional airborne dispersal of tritium and plutonium, and nonexistent in comparing medium-term radwaste hazard potential (1000 to 100,000 years) and intentional waterborne dispersal of tritium and plutonium. Fusion appears to have some qualitative advantages with respect to accident pathways and safeguards considerations. Fusion has the theoretical potential for improvements of 1 to 2 additional orders of magnitude in short-term BHPs and 3 orders of magnitude and more in radwaste BHPs after 10 years if vanadium-titanium alloy can be used in place of stainless steel in the reactor structure. Other important unresolved questions are how much the inventory of tritium can be reduced by ingenious design, and what fraction of a fusion reactor's activation products …

Experimental evidence is presented of a steepened electron density profile near critical density obtained from studying the time-integrated scattered light from targets illuminated by linearly polarized, 1.06 ..mu.. light. Both 10 ..mu.. thick disks and DT-filled glass microshells were irradiated by light focused by f/1 or f/2.5 lenses in one and two-beam experiments, respectively. From the dependence of the asymmetry of the scattered light about the beam axis upon the scattering angle, we infer scale lengths on the order of one micron. Scale lengths have also been deduced from measurements on the polarization state of the reflected light. Both analytic and numerical results are presented to show how the polarization state varies with the incidence angle and the scale length.

The elements of a Nd: Glass laser chain as it is constructed for fusion experiments are described. A brief overview of the ARGUS and SHIVA systems employing Nd lasers is given. (MOW)

Organic aerogels are a special type of low density foam produced from the supercritical drying of resorcinol-formaldehyde (RF) gels. These aerogels have continuous porosity, ultrafine cell/pore sizes (<1000 {angstrom}), and a microstructure composed of interconnected colloidal-like particles with diameters ranging from 30-175 {angstrom}. The particle size, surface area, density, and mechanical properties of the aerogels are largely determined by the catalysts concentration used in the sol-gel polymerization. In order to gain some insight into the crosslinks between RF particles, aerogels were labeled with C-13 formaldehyde at various times in the polymerization. CPMAS and IRCP techniques were used to correlate the relaxation behavior of the C-13 enriched aerogels with their different microstructures. 9 refs., 1 fig., 2 tabs.

The absolute sensitivities of several different types of x-ray detectors were measured between 183 eV and 932 eV. The photons in this energy range were produced by bombarding thin, water-cooled, metal targets with protons from a Cockcroft-Walton ion accelerator. The detectors measured included a silicon-semiconductor detector, two photoelectric-diode detectors employing aluminum and gold photocathodes, and three detectors incorporating plastic scintillators and photodiodes.

The targets used for the creation of laser produced plasmas often contain sodium, silicon and other period 3 elements. Temperature and density information can be inferred from detailed study of the characteristic radiation from these elements. The resolution capabilities of crystal spectrographs designed to look at such target radiation are discussed. Data from several types of spectrographs are compared. The fine structure of the hydrogen and helium-like silicon lines are used to illustrate spectrograph resolution. A spectrograph for examining weak characteristic radiation near 1 keV due to plasma which has been compressed with a spherical irradiation system is discussed.

Included are descriptions of welding methods and joint design, welding equipment, and qualification tests. (DG)

Separate abstracts were prepared for twenty-four papers. (MHR)

The history and state-of-the-art of laser isotope separation at the Lawrence Livermore Laboratory are reviewed. (TFD)

A neutral fraction approaching 97 percent can be attained by photodetachment of negative ions if the photon density and thickness are adequate. This high efficiency of neutralization is desirable not only because of the improvement in power balance and power efficiency but also because of the increase in the useable beam current per module. Only modest improvements in commercial solid-state lasers are required to fulfill the requirements of a photodetachment cell for a fusion reactor. The wavelength of 0.85 x 10/sup -4/ cm is suitable with respect to the photodetachment cross section, the performance characteristics of present-day lasers, and the high reflectivity of the mirrors required for the optical cavity. Improvements may be possible by using resonances in the near ultraviolet region to enhance the photodetachment cross section. Three reactor-design studies were conducted and it was found that the required laser power is only economical for large injection systems in which beams of several hundred amperes are passed through a single optical cavity for photodetachment. The method is not economical for smaller systems.

The dynamic Charpy V-notch test was simulated on a computer. The calculational models (for A-533 Grade B class 1 steel) used both a rounded and a flat-tipped striker. The notch stress/strain state was found to be independent of the three-point loading type and was most strongly correlated with notch-opening displacement. The dynamic stress/strain state at the time of fracture initiation was obtained by comparing the calculated deformed shape with that obtained in interrupted Charpy V-notch tests where cracking had started. The calculation was also compared with stress/strain states calculated in other geometries at failure. The distribution and partition of specimen energy was calculated and adiabatic heating and strain rate are discussed.

Two uses of the Perkin-Elmer (PE) robotic system will be presented. In the first, a PE robot functions as an automatic sample changer for up to five low energy photon spectrometry (LEPS) detectors operated with a Nuclear Data ND 6700 system. The entire system, including the robot, is controlled by an IBM PC-AT using software written in compiled BASIC. Problems associated with the development of the system and modifications to the robot will be presented. In the second, an evaluation study was performed to assess the abilities of the PE robotic system for performing complex analytical sample preparation procedures. For this study, a robotic system based upon the PE robot and auxiliary devices was constructed and programmed to perform the preparation of final product samples (UO{sub 3}) for accountability and impurity specification analyses. These procedures require sample dissolution, dilution, and liquid-liquid extraction steps. The results of an in-depth evaluation of all system components will be presented.

In next-to-leading order quantum chromodynamics, gluon-gluon interactions dominate the production of bottom quarks at hadron collider energies, and gluon-quark interactions control inclusive prompt photon production at large transverse momentum in pp collisions at fixed-target energies. Using such data, in conjunction with data from deep inelastic lepton scattering, we determine a new gluon density whose shape differs substantially from that derived from previous fits of data. The new set of parton densities provides a good fit to bottom quark, prompt photon, and deep inelastic data, including the most recent NMC and CCFR results.

The interaction of oxygen with a thorium metal surface is being studied by monitoring the luminescence of thorium in an electron beam. By combining luminescence measurements with Auger electron spectroscopy data, it is possible to distinguish between processes that depend upon the oxygen pressure at the sample surface, and those that depend only upon the amount of adsorbed oxygen.

Experimental evidence is presented of a steepened electron density profile near critical density obtained from studying the time-integrated scattered light from targets illuminated by linearly polarized, 1.06 ..mu.. light. Both 10 ..mu.. thick disks and DT-filled glass microshells were irradiated by light focused by f/1 or f/2.5 lenses in one and two-beam experiments, respectively. From the dependence of the asymmetry of the scattered light about the beam axis upon the scattering angle, scale lengths on the order of one micron are inferred. Scale lengths have also been deduced from measurements on the polarization state of the reflected light. Both analytic and numerical results are presented to show how the polarization state varies with the incidence angle and the scale length.

Some of the problems to be encountered in the large-scale use of dye lasers in an isotope separation plant are discussed. Why should dye lasers be employed. How can dye conversion efficiency be optimized. How can dye photochemical decomposition and hence running costs be minimized and how serious is this effect anyway. What are toxicity problems with the dye. These and similar issues are examined.

Current practice in the nuclear industry and elsewhere is to specify the seismic input to design calculations at the surface of the site, rather than at bedrock. This paper investigates the implications of such a specification by comparing the site response of a surface specification to the site response of a corresponding bedrock specification. The investigation considered six different sites consisting of three soil profiles with average shear wave velocities of 800, 1800, and 5000 ft/sec and two oil depths: 200 ft. and 400 ft. Seismic input to these sites consisted of two synthetic accelerograms: one corresponding to Blume's statistically averaged surface response spectrum taken as surface input, the other accelerogram was, in our judgment, a typical bedrock acceleration time history related to the surface synthetic accelerogram. The site response was calculated using the program SHAKE. The deconvolution results indicate that Blume's statistically averaged surface response spectrum envelops all the spectra from lower levels for hard and intermediate sites. When the corresponding bedrock acceleration is used as input for a convolution, the surface acceleration can be greater than Blume's surface spectral acceleration. It is very difficult to calculate physically meaningful results for the soft sites for both convolution and deconvolution. …

Laser fusion experiments require hard vacuum in the laser-beam spatial filters, target chambers and for target diagnostics instruments. Laser focusing lenses and windows, and target alignment windows must hold vacuum without optical distortion, and must be protected from target debris. The vacuum must be sufficient to prevent residual gas breakdown in focused laser light, avoid arcing at high voltage terminals, minimize contamination and melting of cryogenic targets, and prevent adsorption of the target's microfusion radiation before it reaches the diagnostics instruments.

For the past decade Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), have been developing and testing a stable, regional coda magnitude methodology for the determination of magnitude and yield. The motivation behind this research was to take advantage of the averaging nature of coda waves in support of monitoring small seismic events from a sparse regional seismic network (e.g., International Monitoring System (IMS) network). The methodology as described in Mayeda et al., (2003) has been successfully applied in a variety of tectonic settings where the assumption of a 1-D, radially symmetric path correction was sufficient. In general, this resulted in inter-station amplitude scatter that was 3-to-4 times smaller than the traditional approach using direct S, Lg and surface waves (0.02< f <8.0-Hz). However, in more laterally complex regions there is a need to extend this approach to account for smaller scale 2-D variations in structure, especially at frequencies above {approx}1-Hz. Recently, Phillips et al., (2003) have applied a 2-D approach to data in central Asia by assuming that the coda envelope amplitude could be idealized as if it were a direct wave. They performed a tomography to invert for Q along the path and through the …

Plasma polarization spectroscopy work done by our group since the 3rd US-Japan PPS Workshop is overviewed. Theoretically, the polarization dependence on various electron distribution functions for He-like, Ne-like, and Ni-like x-ray transitions for a wide range of Z has been investigated. In particular, this study was focused on the polarization dependence for monoenergetic and steep electron distribution functions. The diagnostically important spectral lines and features of K-, L-, and M-shell ions were identified which can be used in x-ray spectropolarimetry of plasma. Importance of polarization-sensitive LLNL Electron Beam Ion Trap data is emphasized. The results of the UNR polarization-sensitive Ti and Mo x-pinch experiments are discussed.

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