We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in developing an appropriate micromechanical constitutive modeling framework, based on a finite element method incorporating a cohesive zone model to represent the binder contribution within a Voronoi tesselation mesh structure for the PBX grains. A second modeling approach was used to incorporate analytical micromechanics (generalized self-consistent schemes). However, preliminary theoretical analysis strongly suggested that this approach would be invalid for such extremely high-filled systems like PBX.

X-ray lasers have been extensively studied around the world since the first laboratory demonstration on the Novette laser at LLNL in 1984. The characteristic properties of short wavelength, high monochromaticity, collimation and coherence make x-ray lasers useful for various applications. These include demonstrations of biological imaging within the water window, interferometry of laser plasmas and radiography of laser-heated surfaces. One of the critical issues has been the high power pump required to produce the inversion. The power scaling as a function of x-ray laser wavelength follows a {approx} {lambda}{sup -4} to {approx} {lambda}{sup -6} law. The shortest x-ray laser wavelength of {approx}35 {angstrom} demonstrated for Ni-like Au was at the limit of Nova laser capabilities. By requiring large, high power lasers such as Nova, the shot rate and total number of shots available have limited the rapid development of x-ray lasers and applications. In fact over the last fifteen years the main thrust has been to develop more efficient, higher repetition rate x-ray lasers that can be readily scaled to shorter wavelengths. The recent state of progress in the field can be found in references. The objective of the project was to develop a soft x-ray laser (XRL) pumped by …

The Project provides for the design, procurement, construction, assembly, installation, and acceptance testing of the National Ignition Facility (NIF), an experimental inertial confinement fusion facility intended to achieve controlled thermonuclear fusion in the laboratory by imploding a small capsule containing a mixture of the hydrogen isotopes deuterium and tritium. The NIF will be constructed at the Lawrence Livermore National Laboratory (LLNL), Livermore, California as determined by the Record of Decision made on December 19, 1996, as a part of the Stockpile Stewardship and Management Programmatic Environmental Impact Statement. Safety: The Incident Analysis and Construction Management Safety Review Teams were formed to review the January 13, 2000, accident in which a worker received a back injury when a 42-in.-diameter duct fell during installation. One action is to contract DuPont to review the Safety Program. Technical Status: The general status of the technologies underlying the NIF Project remains satisfactory. The issues currently being addressed are (1) cleanliness for installation, assembly, and activation of the laser system by Systems Engineering; (2) laser glass--a second pilot run at one of the two commercial suppliers is ongoing successfully; and (3) operational costs associated with final optics assembly (FOA) optics components--methods are being developed to mitigate …

By producing compact representations of hyperspectral image cubes (hypercubes), image storage requirements and the amount of time it takes to extract essential elements of information can both be dramatically reduced. However, these compact representations must preserve the important spectral features within hypercube pixels and the spatial structure associated with background and objects or phenomena of interest. This paper describes a novel approach for automatically and efficiently generating a particular type of compact hypercube representation, referred to as a supercube. The hypercube is segmented into regions that contain pixels with similar spectral shapes that are spatially connected, and the pixel connectivity constraint can be relaxed. Thresholds of similarity in spectral shape between pairs of pixels are derived directly from the hypercube data. One superpixel is generated for each region as some linear combination of pixels belonging to that region. The superpixels are optimal in the sense that the linear combination coefficients are computed so as to minimize the level of noise. Each hypercube pixel is represented in the supercube by applying a gain and bias to the superpixel assigned to the region containing that pixel. Examples are provided.

High-energy cascades have been simulated in gold using molecular dynamics with a modified embedded atom method potential. The results show that both vacancy and interstitial clusters form with high probability as a result of intracascade processes. The formation of clusters has been interpreted in terms of the high pressures generated in the core of the cascade during the early stages. We provide evidence that correlation between interstitial and vacancy clustering exists.

This report documents the Hazards Analysis Report (HAR) Addendum for Buildings 518 and 518A. In summary, the description of the facility and the operations given in the 1995 PHA are the same as the present in this year 2000. The hazards description also remains the same. The hazards analysis in this HAR Addendum is different in that it needs to be compared to operations routinely ''performed'' by the public. The HAR Addendum characterizes the level of intrinsic potential hazards associated with a facility and provides the basis for hazard classification. The hazard classification determines the level of safety documentation required and the DOE order governing the safety analysis. The hazard classification also determines the level of review and approval required for the safety analysis. This facility does not contain any safety class systems or systems important to safety as defined in Department of Energy standard DOE-STD-3009-94. The hazards of primary concern associated with B518 and B518A are chemical in nature. The hazard classification is determined by comparing facility inventories of chemicals with threshold values for the various hazard classification levels. In this way, the hazard level of the facility can be ascertained. The most significant hazards that could affect people …

The Plutonium Immobilization Project is currently undertaking formulation and process development to demonstrate the immobilization of surplus plutonium in a titanate-based ceramic. These ceramic forms will be encapsulated within canisters containing high level waste glass for geologic disposal. Process development work is being conducted with sub-scale, process prototypic equipment. Final validation of the process will be done using actual plutonium material and functionally prototypic equipment within a glovebox. Due to the radioactive nature of the material, remote material handling is necessary to reduce the radiation exposure to the operators. A remote operated Material Transfer System to interface with process equipment has been developed.

The vacuum cathodic arc has been known to provide a means of producing coatings since the second half of the 19th century. This makes it one of the oldest known means for making coatings in a vacuum. In the last century it has been recognized that the copious quantities of ions produced by the process offers certain advantages in terms of coating properties. Specifically, ions can be steered and/or accelerated toward the parts to be coated. This, in turn, can provide enhanced adhesion, film density, and composition stoichiometry in the case of compound coatings. The ions generated by the cathodic arc have high ''natural'' kinetic energy values in the range 20-200 eV, leading to enhanced surface mobility during the deposition process and even ion subplantation. In many cases, dense coatings are achieved even when non-normal arrival angles are involved. The ion energy can further manipulated by the plasma immersion biasing technique. The issue of macroparticle contamination has been addressed by a variety of novel plasma filters. In spite of all of these advantages, this deposition technique has not been widely adopted in the western nations for commercial coating except in the case of enhancing the performance of cutting tools. The …

Algebraic multigrid (AMG) is an attractive choice for solving large linear systems {Lambda}x = b on unstructured grids. While AMG is applicable as a solver for a variety of problems, its robustness may be enhanced by using it as a preconditioner for Krylov solvers, such as GMRES. The sheer size of modern problems, hundreds of millions or billions of unknowns, dictates the use of massively parallel computers. AMG consists of two phases: the setup phase, in which smaller and smaller linear systems are generated by means of linear transfer operators (interpolation and restriction); and the solve phase, which employs a smoothing operator, such as Gauss-Seidel or Jacobi relaxation. Most of these components can be parallelized in a straightforward fashion; however, the coarse-grid selection, in which the grid for a smaller linear system is created on which the error can be approximated, is highly sequential. It is important to develop parallel coarsening techniques. They briefly present here the coarsening algorithms used in the parallel AMG code ''Boomer AMG'' and summarize some performance results for those algorithms. A detailed discussion of the algorithms and numerical results will be found.

The application of coatings over large areas can be approached through the use of large deposition sources. A versatile alternative, e.g. to long rectangular magnetrons, are linear arrays of circular planar magnetrons to process coatings over wide path lengths. They investigate the feasibility of using a linear array of 76 mm diameter magnetron sources operated in the rf mode to deposit oxide target materials across a path in excess of 0.7 m wide. Specific results are given for the case of a 2 {micro}m thick, alumina coating.

This final report describes our efforts on the Three-Dimensional Massively Parallel CEM Technologies LDRD project (97-ERD-009). Significant need exists for more advanced time domain computational electromagnetics modeling. Bookkeeping details and modifying inflexible software constitute a vast majority of the effort required to address such needs. The required effort escalates rapidly as problem complexity increases. For example, hybrid meshes requiring hybrid numerics on massively parallel platforms (MPPs). This project attempts to alleviate the above limitations by investigating flexible abstractions for these numerical algorithms on MPPs using object-oriented methods, providing a programming environment insulating physics from bookkeeping. The three major design iterations during the project, known as TIGER-I to TIGER-III, are discussed. Each version of TIGER is briefly discussed along with lessons learned during the development and implementation. An Application Programming Interface (API) of the object-oriented interface for Tiger-III is included in three appendices. The three appendices contain the Utilities, Entity-Attribute, and Mesh libraries developed during the project. The API libraries represent a snapshot of our latest attempt at insulated the physics from the bookkeeping.

The growth of computer power and connectivity, together with advances in wireless sensing and communication technologies, is transforming the field of complex distributed systems. The ability to deploy large numbers of sensors with a rapid, broadband communication system will enable high-fidelity, near real-time monitoring of complex systems. These technological developments will provide unprecedented insight into the actual performance of engineered and natural environment systems, enable the evolution of many new types of engineered systems for monitoring and detection, and enhance our ability to perform improved and validated large-scale simulations of complex systems. One of the challenges facing engineering is to develop methodologies to exploit the emerging information technologies. Particularly important will be the ability to assimilate measured data into the simulation process in a way which is much more sophisticated than current, primarily ad hoc procedures. The reports contained in this section on the Center for Complex Distributed Systems describe activities related to the integrated engineering of large complex systems. The first three papers describe recent developments for each link of the integrated engineering process for large structural systems. These include (1) the development of model-based signal processing algorithms which will formalize the process of coupling measurements and simulation and …

The initial goal of this project was to study the in-medium nucleon-nucleon interaction by testing the fundamental theory of nuclear structure, the shell model, for nuclei between {sup 8}Zr and {sup 100}Sn. The shell model predicts that nuclei with ''magic'' (2,8,20,28,40,50, and 82) numbers of protons or neutrons form closed shells in the same fashion as noble gas atoms [may49]. A ''doubly magic'' nucleus with a closed shell of both protons and neutrons has an extremely simple structure and is therefore ideal for studying the nucleon-nucleon interaction. The shell model predicts that doubly magic nuclei will be spherical and that they will have large first-excited-state energies ({approx} 1 to 3 MeV). Although the first four doubly-magic nuclei exhibit this behavior, the N = Z = 40 nucleus, {sup 80}Zr, has a very low first-excited-state energy (290 keV) and appears to be highly deformed. This breakdown is attributed to the small size of the shell gap at N = Z = 40. If this description is accurate, then the N = Z = 50 doubly magic nucleus, {sup 100}Sn, will exhibit ''normal'' closed-shell behavior. The unique insight provided by doubly-magic nuclei from {sup 80}Zr to {sup 100}Sn has made them the …

As an integral part of the plutonium disposition program, formulation and process development is being performed for the immobilization of surplus plutonium in a titanate-based ceramic. Small-scale process prototypic and lab-scale functionally prototypic equipment have been tested to help define the immobilization process. The testing has included non-radioactive surrogates and actual actinide oxides contained in the immobilized form. A summary of the process development studies, as well as the formulation studies relevant to the process, will be provided.

The study of sonoluminescence has been under taken to determine the mechanisms for the production of the short burst of light that arises in an acoustically driven water cell. The investigations have reached a state of understanding where the underlying physical processes causing the conversion of acoustic energy to radiation can now be successfully simulated. Further, the effort has led to substantial outreach to the community including undergraduate student, post-graduate students, and professors. Finally, the experimental program has provided important information on the region where sonoluminescence works.

Over the course of the year 2000, five one-day workshops were conducted by the Center for Global Security Research at the Lawrence Livermore National Laboratory on threats that might come against the US and its allies in the 2015 to 2020 timeframe due to the global availability of advanced technology. These workshops focused on threats that are enabled by nuclear, missile, and space technology; military technology; information technology; bio technology; and geo systems technology. In December, an Integration Workshop and Senior Review before national leaders and experts were held. The participants and reviewers were invited from the DOE National Laboratories, the DOD Services, OSD, DTRA, and DARPA, the DOS, NASA, Congressional technical staff, the intelligence community, universities and university study centers, think tanks, consultants on national security issues, and private industry. For each workshop the process of analysis involved identification and prioritization of the participants' perceived most severe threat scenarios (worst nightmares), discussion of the technologies which enabled those threats, and ranking of the technologies' threat potentials. We were not concerned in this exercise with defining responses, although our assessment of each threat's severity included consideration of the ease or difficulty with which it might be countered. At the concluding …

A phenomenological model is proposed to correlate the onset of solid-state amorphization with the loss of interfacial stability in Ni-Ti multilayers. Additionally, a temperature dependence to the onset of amorphization is attributed to the effect of interfacial coherency that varies with the Ni-Ti layer pair spacing.

Mask blanks are the substrates that hold the master patterns for integrated circuits. Integrated circuits are semiconductor devices, such as microprocessors (mPs), dynamic random access memory (DRAMs), and application specific integrated circuits (ASICs) that are central to the computer, communication, and electronics industries. These devices are fabricated using a set of master patterns that are sequentially imaged onto light-sensitive coated silicon wafers and processed to form thin layers of insulating and conductive materials on top of the wafer. These materials form electrical paths and transistors that control the flow of electricity through the device. For the past forty years the semiconductor industry has made phenomenal improvements in device functionality, compactness, speed, power, and cost. This progress is principally due to the exponential decrease in the minimum feature size of integrated circuits, which has been reduced by a factor of {radical}2 every three years. Since 1992 the Semiconductor Industry Association (SIA) has coordinated the efforts of producing a technology roadmap for semiconductors. In the latest document, ''The International Technology Roadmap for Semiconductors: 1999'', future technology nodes (minimum feature sizes) and targeted dates were specified and are summarized in Table 1. Lithography is the imaging technology for producing a de-magnified image of …

The National Ignition Facility will be the largest laser system in the world. The facility, currently under construction, requires over 25,000 small optical components. The small-optics requirements and latest procurement strategy will be presented.

The following arrival information is a supplement to Myers and Schultz (2000). Myers and Schultz (2000) demonstrate the improvement in sparse-network location that can be achieved by using travel-time corrections determined with a Bayesian Kriging algorithm (Schultz et al., 1998). Precise, benchmark locations are provided by a local aftershock study of the 1991 Racha, Georgia earthquake sequence in the Caucasus Mountains (Fuenzalida et al., 1997). A test network is used to relocate the aftershocks with and without travel-time corrections. The test network is meant to represent a typical International Monitoring System configuration, with 6 stations at regional to near teleseismic distances (less then 30{sup o} from the epicenter). The following arrival-time data help to facilitate the reproduction of Myers and Schultz (2000). The arrival picks were obtained from the International Seismic Center (ISC) (openly available) and a Lawrence Livermore National Laboratory (LLNL) analyst (Flori Ryan). Table 1 lists the arrivals in epic time (time since January 1, 1970). The author of the arrival pick is listed as either ''flori'' or ''-'', where ''-'' indicates ISC. Table 2 lists the hypocenter information determined in the local aftershock study of Fuenzalida et al. (1997), and Table 3 lists the station information for …

We show that standard tissue phantoms can be used to mimic the intensity and polarization properties of tissue. Polarized light propagation through biologic tissue is typically studied using tissue phantoms consisting of dilute aqueous suspensions of microspheres. The dilute phantoms can empirically match tissue polarization and intensity properties. One discrepancy between the dilute phantoms and tissue exist: common tissue phantoms, such as dilute Intralipid and dilute 1-{micro}m-diameter polystyrene microsphere suspensions, depolarize linearly polarized light more quickly than circularly polarized light. In dense tissue, however, where scatterers are often located in close proximity to one another, circularly polarized light is depolarized similar to or more quickly than linearly polarized light. We also demonstrate that polarized light propagates differently in dilute versus densely packed microsphere suspensions, which may account for the differences seen between polarized light propagation in common dilute tissue phantoms versus dense biologic tissue.

The goal of the Plutonium Immobilization Program is the immobilization of surplus weapons usable plutonium in a ceramic form. The ceramic will then be encapsulated in high level waste glass using the can-in-can configuration. In the ceramic line of the immobilization plant, surplus plutonium oxide of less than 100 micron particle size will be received for immobilization. The plutonium oxide must be sized reduced and intimately blended with uranium oxide and the other ceramic forming materials containing neutron poisons to allow for complete interaction during sintering. Once properly blended, the formulation will be pressed into the desired ceramic form and then sintered to produce the targeted mineral phases. The equipment of choice for the size reduction of the actinides and the blending with the precursor materials is the Union Process attritor mill. The attritor mill is best described as a stirred ball mill and consists of a stationary tank filled with grinding media that is agitated by a shaft with stirring arms. The rotational shaft stirs the media at high-speed causing shearing and impact forces on the material resulting in size reduction and dispersion. Speeds over 1000 rpm can be reached by the stirring shaft. The high-speed of the attritor …

Stable isotope measurements of surface water and groundwater from the Burney Basin and northern Hat Creek Basin indicate that spring discharge at Burney Falls is a mixture of water derived from both basins. Relative mixing proportions depend on the assumed isotopic composition of each end-member, but plausible mixing models suggest that approximately 40 to 60% of the spring water originates from the Burney Basin. The isotope data also indicate that Burney Creek cannot be the dominant source of Burney Falls Springs. The proposed development of a new power plant (Three Mountain Project) in the Burney Basin area of northeastern California provided the impetus for this brief report on the origin of groundwater discharge at Burney Falls Springs. The proposed project is situated {approx} 13 km up-gradient of McArthur-Burney Falls Memorial State Park, where groundwater emanates from a group of large springs at a rate of approximately 4.2 to 6.4 m{sup 3}s{sup -1} (150-225 ft{sup 3}s{sup -1}). This report discusses stable isotope data for water samples that were gathered from this region by the author in the mid-1990's. The intent is to provide impartial scientific evidence that may assist in the environmental risk assessment process.

This report addresses issues related to the analysis of uncertainty in dose assessments conducted as part of decommissioning analyses. The analysis is limited to the hydrologic aspects of the exposure pathway involving infiltration of water at the ground surface, leaching of contaminants, and transport of contaminants through the groundwater to a point of exposure. The basic conceptual models and mathematical implementations of three dose assessment codes are outlined along with the site-specific conditions under which the codes may provide inaccurate, potentially nonconservative results. In addition, the hydrologic parameters of the codes are identified and compared. A methodology for parameter uncertainty assessment is outlined that considers the potential data limitations and modeling needs of decommissioning analyses. This methodology uses generic parameter distributions based on national or regional databases, sensitivity analysis, probabilistic modeling, and Bayesian updating to incorporate site-specific information. Data sources for best-estimate parameter values and parameter uncertainty information are also reviewed. A follow-on report will illustrate the uncertainty assessment methodology using decommissioning test cases.