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Structural distortions that compete with superconductivity have been investigated in two systems where oxygen content can be used to vary the doping continuously from the under doped state, through the maximum T{sub c} into the over doped state. In the 123 system, (La{sub 1{minus}x}Ca{sub x})(Ba{sub 1.75{minus}x}La{sub 0.25+x})Cu{sub 3}O{sub 7+{delta}}, the buckling of the CuO{sub 2} planes goes through a maximum at the maximum T{sub c}. In HgBa{sub 2}CuO{sub 4+{delta}}, where buckling of the CuO{sub 2} planes is not available as a structural degree of freedom, there is a plateau at the maximum T{sub c} where the unit cell volume expands as oxygen is added while the charge transfer and T{sub c} remain constant. These unusual structural phenomena upon crossing through the maximum T{sub c} are hypothesized to be a response of the crystal structure to the electronic structure, with the structural distortions competing with superconductivity, or lowering the T{sub c} from what it would otherwise be.

We have used Raman ''fingerprinting'' to investigate the temperature dependence of the transient oxide phases in the scale formed on MCrAl and MCrAlY (M=Ni,Co) in the temperature range 300 to 1200 C. In particular, by extending our Raman spectra to include second order scattering, we are able to track the evolution of NiO in the scales. We find that the inclusion of Y, while improving scale adhesion, inhibits the formation of Co oxide. We have also exploited the strain dependence of ruby fluorescence to extract the residual strain in the oxide scale.

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We review the derivation of moment equations which include the effects of space charge and dispersion in bends first presented in ref [1]. These equations generalize the familiar envelope equations to include the dispersive effects of bends. We review the application of these equations to the calculation of the change in emittance resulting from a sharp transition from a straight section to a bend section, using an energy conservation constraint. Comparisons of detailed 2D and 3D simulations of intense beams in rings using the WARP code (refs [2,3]) are made with results obtained from the moment equations. We also compare the analysis carried out in ref [1], to more recent analyses, refs [4,5]. We further examine self-consistent distributions of beams in bends and discuss the relevance of these distributions to the moment equation formulation.

Intense laser (> 10{sup 21} W/cm{sup 2}) driven hard x-ray sources offer a new alternative to conventional electron accelerator bremsstrahlung sources. These laser driven sources offer considerable simplicity in design and cost advantage for multiple axis views and have the potential for much higher spatial and temporal resolution than is achievable with accelerator sources We have begun a series of experiments using the Petawatt Laser system at LLNL to determine the potential of these sources for radiography applications Absolutely calibrated spectra extending to 20 MeV and high resolution radiographs through a {rho}r{>=}150 gm/cm{sup 2} have been obtained The physics of these sources and the scaling relationships and laser technology required to provide the dose levels necessary for radiography applications will be discussed Diagnostics of the laser produced electrons and photons will be addressed

We report on a diagnostic to measure the trajectory of a blast wave propagating through a plastic target 400 {micro}m thick. This blast wave is generated by the irradiation of the front surface of the target with {approximately} 400 J of 1 {micro}m laser radiation in a 20 ps pulse focused to a {approximately} 50 {micro}m diameter spot, which produces an intensity in excess of 1O{sup 18} W/cm{sup 2}. These conditions approximate a point explosion and a blast wave is predicted to be generated with an initial pressure nearing 1 Gbar which decays as it travels approximately radially outward from the interaction region We have utilized streaked optical pyrometry of the blast front to determine its time of arrival at the rear surface of the target Applications of a self-similar Taylor-Sedov blast wave solution allows the amount of energy deposited to be estimated The experiment, LASNEX design simulations and initial results are discussed.

This Project Management Plan (PMP) describes the manner in which the US Department of Energy Nevada Operations Office (DOE/NV) will manage the Underground Test Area (UGTA) Subproject at the Nevada Test Site (NTS). It provides the basic guidance for implementation and the organizational structure for meeting the UGTA objectives.

Refracted X-Ray Fluorescence (RXF) is applied to the study of the thermally grown scales on Fe25Cr20Ni(RE) alloys. The evolution of chromia scales is investigated for alloys containing reactive elements (RE) Y and Zr as well as the corresponding RE-free alloy. For these alloys, scale compositions, scale thicknesses and growth rates are measured and information about concentration depth profiles is obtained.

The use of local probes at specific spatial locations provides a clear picture of the scale growth. The thermal evolution of the oxide scale on 72Fe-18Cr-10Al-0.15Hf (at.%) has been investigated using a number of spectroscopic techniques. Well defined regions ({approx}70 mm in diameter) were probed by a battery of techniques as a function of oxidation at different temperatures (Between 800 C--1100 C). This study provides information about the dependence of scale evolution on fluctuations in the local composition and/or grain structure of the starting material. Results suggest that properties of the starting material, which were not investigated in this study, strongly influence the scale evolution, even to the stage of mature scales.

A computer model for systems analysis of heavy ion drivers based on induction linac technology has been used to evaluate driver designs for inertial fusion energy (IFE). Design parameters and estimated costs have been determined for drivers with various ions, different charge states, different front-end designs, with and without beam merging, and various pulse compression and acceleration schedules. We have examined the sensitivity of the results to variations in component cost assumptions, design constraints, and selected design parameters

According to the American Institute of Stress, job stress is estimated to cost American industry more than $200 billion a year. These costs are, in part, related to the estimated 1 million employees that will be absent on an average workday because of stress; 75 percent of visits to primary care physicians are for stress-related problems. California workers' compensation claims for stress cost $1 billion for medical and legal fees alone (Murphy, 1997). But, there is another dimension to stress that needs to be addressed. Job stress can be a precursor to job burnout. Burnout is a loss of motivation, and antidotes for job stress will not necessarily alleviate or stop job burnout. Job burnout is experienced as exhaustion on physical, emotional, and cognitive levels. Burnout can include withdrawal and decreasing involvement on the job, seriously affecting job satisfaction, turnover, absenteeism, and productivity (Dwyer & Ganster, 1991; Erickson & Gunderson, 1972; Spector & Jex, 1991). The research project described in this paper examined whether job burnout exists in the technical writer and technical illustrator/designer occupations in the Technical Information Department at Lawrence Livermore National Laboratory. This study also determined at what age and after how many years of service these …

We have investigated the residual stress near edges and corners of thermally grown alumina scales. Micro-fluorescence measurements, performed on alloys with composition Fe-5Cr-28Al (at.%, bal. Fe) oxidized at 900 C, showed a large (>50%) reduction in hydrostatic stress in the vicinity of edges and corners. Surprisingly, stress relaxation persists out to distances ten times the scale thickness from the edge. Finite element analysis calculations confirm the experimental results and provide a considerably more detailed picture of the stress distribution and its components.

Compilation of monthly reports from departments in the city of San Antonio, Texas providing statistics, project updates, and other information about services and activities.

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