The NIF contains a large number of optics that also act as vacuum barriers. These are subject to brittle failures that may result in significant consequences. This Fracture Control Plan identifies the requirements, needed documentation, and required actions for minimizing the potential for brittle failures of these fracture critical components in the NIF laser system. The goal of this plan is to ensure that all fracture-critical systems present no more than a low level of risk. Risk considers both consequences (to workers, the environment, and public confidence) and probability of failure. This plan interprets and implements the guidance contained in the ME Design Safety Standard, Section 5.4, ''Design Safety Standards for Fracture Critical Components for High Power Laser Systems'' (LLNL, 2000).

Over the past 10 years we have developed methods for imaging the electrical resistivity of soil and rock formations. These technologies have been called electrical resistance tomography of ERT (e.g. Daily and Owen, 1991). Recently we have been striving to extend this capability to include images of electric impedance--with a new nomenclature of electrical impedance tomography or EIT (Ramirez et al., 1999). Electrical impedance is simply a generalization of resistance. Whereas resistance is the zero frequency ratio of voltage and current, impedance includes both the magnitude and phase relationship between voltage and current at frequency. This phase and its frequency behavior is closely related to what in geophysics is called induced polarization or (Sumner, 1976). Why is this phase or IP important? IP is known to be related to many physical phenomena of importance so that image of IP will be maps of such things as mineralization and cation exchange IP (Marshall and Madden, 1959). Also, it is likely that IP, used in conjunction with resistivity, will yield information about the subsurface that can not be obtained by either piece of information separately. In order to define the accuracy of our technologies to image impedance we have constructed a physical …

None

None

Femtosecond laser ablation has been shown to produce well-defined cuts and holes in metals with minimal heat effect to the remaining material. Ultrashort laser pulse processing shows promise as an important technique for materials processing. We will discuss the physical effects associated with processing based experimental and modeling results. Intense ultra-short laser pulse (USLP) generates high pressures and temperatures in a subsurface layer during the pulse, which can strongly modify the absorption. We carried out simulations of USLP absorption versus material and pulse parameters. The ablation rate as function of the laser parameters has been estimated. Since every laser pulse removes only a small amount of material, a practical laser processing system must have high repetition rate. We will demonstrate that planar ablation is unstable and the initially smooth crater bottom develops a corrugated pattern after many tens of shots. The corrugation growth rate, angle of incidence and the polarization of laser electric field dependence will be discussed. In the nonlinear stage, the formation of coherent structures with scales much larger than the laser wavelength was observed. Also, there appears to be a threshold fluence above which a narrow, nearly perfectly circular channel forms after a few hundred shots. Subsequent …

The use of liquid walls for fusion reactors could help solve problems associated with material erosion from high plasma heat-loads and neutronic activation of structures. A key issue analyzed here is the influx of impurity ions to the core plasma from the vapor of liquid side-walls. Numerical 2D transport simulations are performed for a slab geometry which approximates the edge region of a reactor-size tokamak. Both lithium vapor (from Li or SnLi walls) and fluorine vapor (from Flibe walls) are considered for hydrogen edge-plasmas in the high- and low-recycling regimes. It is found that the minimum influx is from lithium with a low-recycling hydrogen plasma, and the maximum influx occurs for fluorine with a high-recycling hydrogen plasma.

The ability of optical materials to withstand high power ultraviolet (UV) laser irradiation without sustaining irrevocable damage is critically important in two areas central to LLNL: laser fusion and UV lithography. In particular, the output fluence of the National Ignition Facility (NIF) is limited by the 351 nm laser damage thresholds of the KH{sub 2}PO{sub 4} (KDP) frequency conversion crystals. The ability to increase the laser output would maximize the odds of achieving ignition, allow target physicists to assess target performance at higher drives, and provide higher temperature-density conditions for studies of the physics of stellar interiors. Moreover, in order to meet the current design criteria for fusion laser systems, KDP crystals must be conditioned by illumination with low fluence laser irradiation to increase the damage threshold by about a factor of two. Over the past two decades, LLNL generated an extensive data base on laser damage and conditioning in KDP and DKDP crystals. While the damage thresholds have improved over time--primarily in response to better filtration of growth solutions--they are still far below what is expected from the band structure of the perfect crystal. Thus these empirical studies have shown that damage in KDP, like the other NIF optical …

Unlike self-supported electrolyte cells, the electrode-supported cells always have one electrode (the support electrode) larger than the other electrode. The conventional approach is then to normalize the power output to the small electrode area. In some cases, the power density is normalized to the area of the current collector, which is even smaller than the area of the small electrode [1]. However, it is unclear whether the current density and the power density are truly independent of the cathode/anode size ratio as is implicitly assumed in the above normalization practices. The aim of this study is to investigate the change in normalized power density with the different electrode area ratios well as the effect of the current collector area. We fabricated NiO-YSZ anode supported fuel cell with yttria-stabilized zirconia (YSZ) as thin film electrolyte and (La,Sr)MnO{sub 3}-YSZ as the composite cathode. Cells with asymmetric and symmetric electrode geometry were prepared by depositing the cathode with different areas. Two cases were studied: poor cathode/good anode cells and good cathode/good anode cells. The poor cathodes and the good cathodes were deposited using the screen-printing technique and the Colloidal Spray Deposition process respectively (2). The symmetric cell with a screen-printed cathode had a …

The scope of the Mercury Laser project encompasses the research, development, and engineering required to build a new generation of diode-pumped solid-state lasers for Inertial Confinement Fusion (ICF). The Mercury Laser will be the first integrated demonstration of laser diodes, crystals, and gas cooling within a scalable laser architecture. This report is intended to summarize the progress accomplished during the first three years of the project. Due to the technological challenges associated with production of 900 nm diode-bars, heatsinks, and high optical-quality Yb:S-FAP crystals, the initial focus of the project was primarily centered on the R&D in these three areas. During the third year of the project, the R&D continued in parallel with the development of computer codes, partial activation of the laser, component testing, and code validation where appropriate.

In accordance with EM guidance, the TFA conducted a Midyear Review to validate and document the maturity and progress of the projects in its portfolio. The initial phase of the review took place February 2-4, 2000, in Las Vegas, NV. This technical review focused on assessing the completeness and adequacy of the TFA's technical strategy in response to user needs. The second phase of the review was held on March 7-8, 2000, also in Las Vegas, NV. This review included the participation of key program, technical, and advisory personnel, focusing on reaffirming project relevance and providing a status on the progress of each technology toward meeting end user requirements, including readiness to advance to the next stage of development. The third phase of the review took place in Atlanta, GA on April 25-27,2000, at the Environmental Management Science Program National Workshop. This workshop provided an opportunity for the TFA to review completed and ongoing basic science research and evaluate its potential applicability to TFA's customers. This report provides an explanation of the TFA review process, an overview of the TFA program, and highlights the results of the FY 2000 Midyear Review. A brief overview of each project reviewed is provided, …

Radiation protection services performed routinely by Pacific Northwest National Laboratory for the U.S. Department of Energy Richland Operations Office and Hanford Site contractors are summarized in this annual report for 1999. It addresses services and special studies or investigations provided by the primary projects managed under the Radiation and Health Technology group, including external dosimetry, internal dosimetry, whole body counting, radiation records, instrumentation services and technology, and radiation standards and calibrations.

Borehole Data Package for Wells 299-W22-48, 299-W22-49, and 299-W22-50 at Single-Shell Tank Waste Management Area S-SX

Post-Remediation Biomonitoring of Pesticides and Other Contaminants in Marine Waters and Sediment Near the United Heckathorn Superfund Site, Richmond, California

Final report of the Federal Trade Commission Advisory Committee on Online Access and Security describing their activities and findings regarding access and security as it relates to online information collected by commercial websites on consumers.

Monthly newsletter from the Texas State Board of Public Accountancy regarding updates and information pertaining to Texas CPAs.

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.

Monthly report discussing cancer care and research to inform physicians.

This proposal consists of five parts and two appendices. The first part provides a detailed physics justification for the BTe V experiment. The second part presents the considerations that drive the detector design, followed by a description of the detector itself. The third part summarizes our simulation results which demonstrate that the design does enable us to achieve our physics goals. The fourth part compares BTeV's physics reach to that of other experiments which will be active in B physics in the same time period. The fifth part gives a very brief, high level summary of the cost estimate for BTeV. Appendix A has additional technical details about many of the detector subsystems and R&D plans; it is intended to be read primarily by experts in each area. Appendix B contains a roadmap which describes the location in the proposal of the answers to questions posed to the BTeV collaboration by the Fermilab Program Advisory Committee in June of 1999.

Antiprotons for the Collider will be bunched in the Accumulator using a RF system (ARF4) that operates at a frequency that is four times the revolution frequency of the Accumulator. Four bunches can be extracted from the Accumulator in a single transfer. Since the TEVATRON will operate with 36 antiproton bunches, nine extractions from the Accumulator will be needed. During Run 1, the momentum distribution of the Accumulator core was shaped by the core cooling systems and was approximately gaussian. After an antiproton bunch was extracted from the core, the momentum spread of the beam was increased because of RF displacement. The beam would then be recooled which would delay shot setup (or the phase space density of subsequent extractions would be diluted). Since the number of extractions per shot for Run II is increasing by 50% (from 6 to 9), the extra time due to re-cooling (or the alternative of momentum phase space dilution) might not be acceptable. This note will outline a scheme that will shape the momentum distribution into a rectangle and will extract the beam from the edges of the distribution so that RF displacement is minimized.

Bimonthly publication of the Texas Veterans Commission discussing specific topics of relevance to veterans in Texas. This pamphlet gives an overview of activities by the VA serving veterans of the Korean War and a brief description of the war in honor of the 50th anniversary of the Korean War.

Magazine for the state agency serving the needs of Texas veterans and their families in matters pertaining to veterans' benefits, rights, education, and employment.

Summary describing the work completed at Southeastern Louisiana University for 'Potential for Accelerated Bioremediation and Restoration of Oil-Impacted Marshes Through the Selection of Superior Oil-Tolerant Vegetation.' It includes background information on the project funding and sponsorship, goals, methodology, and findings.