We developed a two stage Ti:Sapphire laser system to generate 16 mJ/80fs laser pulses at the pulse repetition rate of 10 Hz. The key deriver for the present design is implementing a highly efficient symmetric confocal pre-amplifier and employing a simple, inexpensive synchronization scheme relying only on a commercial digital delay-generator. We characterized the amplified pulses in spatial-, spectral-, and temporal-domains. The laser system was used to investigate various nonlinear optical processes, and to modify the optical properties of metal- and semiconductor-surfaces. We are currently building a third amplifier to boost the laser power to the multi-terawatt range.

Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent approximately daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998. The U.S. Department of Energy (DOE) requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1 - (ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the first quarter of FY 2010 for the North Slope Alaska (NSA) locale is 1,987.20 hours (0.90 x 2,208); for the Southern Great Plains (SGP) site is 2,097.60 hours (0.95 x 2,208); and …

Fiber Sensors are poised to be used in future LEPs. The three primary vehicles for fiber sensors are Department 1, Joint Test Assembly (JTA), and Shelf Life (SL). The National Security Enterprise (NSE) community plans to incorporate optical sensors or systems into these vehicles. Additionally, hermetic sealing of optical systems is required if optical technology is to be integrated into LEP and future weapons applications. Hermetic seals will reduce the long-term risk of contamination which can degrade or incapacitate optical components. This study was funded through the Kansas City Plant's (KCP) ESC work package between 2007 and 2009 to develop optical sensors, identify commercial fiber sensors and hermetic connectors, and qualify these sensors against likely weapon lifetime environments.

Washington River Protection Solutions (WRPS) under contract from the U.S. Department of Energy (DOE) is responsible for assessing the condition of the double-shell tanks (DST) on the Hanford nuclear site. WRPS has contracted with AREVA Federal Services LLC (AFS) to perform ultrasonic testing (UT) inspections of the 28 DSTs to assess the condition of the tanks, judge the effects of past corrosion control practices, and satisfy a regulatory requirement to periodically assess the integrity of the tanks. Since measurement inception in 1997, nine waste tanks have been examined twice (at the time of this report) providing UT data that can now be compared over specific areas. During initial reviews of these two comparable data sets, average UT wall-thickness measurement reductions were noted in most of the tanks. This variation could be a result of actual wall thinning occurring on the waste-tanks walls, or some other unexplained anomaly resulting from measurement error due to causes such as the then-current measurement procedures, operator setup, or equipment differences. WRPS contracted with the Pacific Northwest National Laboratory (PNNL) to assist in understanding why this variation exists and where it stems from.

The dynamics of the reshocked multi-mode Richtmyer-Meshkov instability is investigated using 513 x 257{sup 2} three-dimensional ninth-order weighted essentially nonoscillatory shock-capturing simulations. A two-mode initial perturbation with superposed random noise is used to model the Mach 1.5 air/SF{sub 6} Vetter-Sturtevant shock tube experiment. The mass fraction and enstrophy isosurfaces, and density cross-sections are utilized to show the detailed flow structure before, during, and after reshock. It is shown that the mixing layer growth agrees well with the experimentally measured growth rate before and after reshock. The post-reshock growth rate is also in good agreement with the prediction of the Mikaelian model. A parametric study of the sensitivity of the layer growth to the choice of amplitudes of the short and long wavelength initial interfacial perturbation is also presented. Finally, the amplification effects of reshock are quantified using the evolution of the turbulent kinetic energy and turbulent enstrophy spectra, as well as the evolution of the baroclinic enstrophy production, buoyancy production, and shear production terms in the enstrophy and turbulent kinetic transport equations.

Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and …

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The objectives of the confirmatory survey were to verify that remedial actions were effective in meeting established release criteria and that documentation accurately and adequately described the final radiological conditions of the RAM Ambrosia Lake, Section 4 Areas.

As the quality of EUV-wavelength mask inspection microscopes improves over time, the image properties and intensity profiles of reflected light can be evaluated in ever-greater detail. The SEMATECH Berkeley Actinic Inspection Tool (AIT) is one such microscope, featuring mask resolution values that match or exceed those available through lithographic printing in current photoresists. In order to evaluate the defect detection sensitivity of the AIT for dense line patterns on typical masks, the authors study the line width roughness (LWR) on two masks, as measured in the EUV images. They report the through-focus and pitch dependence of contrast, image log slope, linewidth, and LWR. The AIT currently reaches LWR 3{sigma} values close to 9 nm for 175 nm half-pitch lines. This value is below 10% linewidth for nearly all lines routinely measured in the AIT. Evidence suggests that this lower level may arise from the mask's inherent pattern roughness. While the sensitivity limit of the AlT has not yet been established, it is clear that the AIT has the required sensitivity to detect defects that cause 10% linewidth changes in line sizes of 125 nm and larger.

Summarizes research conducted at Bonneville Dam in 2008 to evaluate a prototype Behavioral Guidance Structure, that was deployed by the US Army Corps of Engineers in an effort to increase survival of outmigrating smolts at Bonneville Dam.

Decadal samples of dendrochronologically-dated pine (Lagorostrobos franklinii) from the Stanley River basin, Tasmania have been radiocarbon dated between 2120-850 yr BP. This data set overlaps and extends the current Southern Hemisphere record, which currently covers the period 110-995 yr BP. There is good agreement between the two records between 995-850 yr BP, between sample replicates and with consensus values for standards. As in the younger dataset, we find evidence for a distinct but variable offset between the southern hemisphere data and IntCal04; although this is likely due to real temporal variability in the interhemispheric offset, further work is planned to rule out possible laboratory or sample preparation differences.

The Hanford Nuclear Reservation occupies an area of 586 square miles in southeastern Washington state. The site was created as part of the World War II Manhattan Project to produce weapons grade plutonium. A multitude of old reactor plants, processing facilities, underground tank farms, contaminated soil and ground water remain and are part of an on-going environmental cleanup mission of the site. The Columbia River bisects Hanford, and the concern is that the river will become contaminated if the sources of contamination are not removed. Currently facilities are being removed, the ground water is being treated, and contaminated soil is being transferred to an approved burial ground about 15 miles away from the River located in the center of the Hanford Site The remaining facilities and adjacent structures are undergoing D&D (decontaminate and demolish) and to date, significant progress has been made. During this presentation, I will discuss how we are using innovative tools and work practices to D&D these Hanford Site facilities.

Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of …

Analysis of the magnetic field structure from electromagnetic simulations of tokamak ion temperature gradient turbulence demonstrates that the magnetic field can be stochastic even at very low plasma pressure. The degree of magnetic stochasticity is quantified by evaluating the magnetic diffusion coefficient. We find that the magnetic stochasticity fails to produce a dramatic increase in the electron heat conductivity because the magnetic diffusion coefficient remains small.

Recently, the direct-strike lighting environment for the stockpile-to-target sequence was updated [1]. In [1], the severe (1%) lightning current waveforms for first and subsequent return strokes are defined based on Heidler's waveform. This report presents numerical calculations of the spectra of those 1% lightning current waveforms and their first derivatives. First, the 1% lightning current models are repeated here for convenience. Then, the numerical method for calculating the spectra is presented and tested. The test uses a double-exponential waveform and its first derivative, which we fit to the previous 1% direct-strike lighting environment from [2]. Finally, the resulting spectra are given and are compared with those of the double-exponential waveform and its first derivative.

Advances in the ability to generate extremely high pressures in dynamic experiments such as at the National Ignition Facility has motivated the need for special materials optimized for those conditions as well as ways to probe the response of these materials as they are deformed. We need to develop a much deeper understanding of the behavior of materials subjected to high pressure, especially the effect of rate at the extremely high rates encountered in those experiments. Here we use large-scale molecular dynamics (MD) simulations of the high-rate deformation of nanocrystalline tantalum at pressures less than 100 GPa to investigate the processes associated with plastic deformation for strains up to 100%. We focus on 3D polycrystalline systems with typical grain sizes of 10-20 nm. We also study a rapidly quenched liquid (amorphous solid) tantalum. We apply a constant volume (isochoric), constant temperature (isothermal) shear deformation over a range of strain rates, and compute the resulting stress-strain curves to large strains for both uniaxial and biaxial compression. We study the rate dependence and identify plastic deformation mechanisms. The identification of the mechanisms is facilitated through a novel technique that computes the local grain orientation, returning it as a quaternion for each atom. …

The two main forcings that can counteract to some extent the positive forcings from greenhouse gases from pre-industrial times to present-day are the aerosol and related aerosol-cloud forcings, and the radiative response to changes in surface albedo. Here, we quantify the change in radiative forcing and land surface temperature that may be obtained by increasing the albedos of roofs and pavements in urban areas in temperate and tropical regions of the globe by 0.1. Using the catchment land surface model (the land model coupled to the GEOS-5 Atmospheric General Circulation Model), we quantify the change in the total outgoing (outgoing shortwave+longwave) radiation and land surface temperature to a 0.1 increase in urban albedos for all global land areas. The global average increase in the total outgoing radiation was 0.5 Wm{sup -2}, and temperature decreased by {approx}0.008 K for an average 0.003 increase in surface albedo. These averages represent all global land areas where data were available from the land surface model used and are for the boreal summer (June-July-August). For the continental U.S. the total outgoing radiation increased by 2.3 Wm{sup -2}, and land surface temperature decreased by {approx}0.03 K for an average 0.01 increase in surface albedo. Based on …

The steepest descent method has a rich history and is one of the simplest and best known methods for minimizing a function. While the method is not commonly used in practice due to its slow convergence rate, understanding the convergence properties of this method can lead to a better understanding of many of the more sophisticated optimization methods. Here, we give a short introduction and discuss some of the advantages and disadvantages of this method. Some recent results on modified versions of the steepest descent method are also discussed.

We describe the imaging and characterization of native defects on a full field extreme ultraviolet (EUV) mask, using several reticle and wafer inspection modes. Mask defect images recorded with the SEMA TECH Berkeley Actinic Inspection Tool (AIT), an EUV-wavelength (13.4 nm) actinic microscope, are compared with mask and printed-wafer images collected with scanning electron microscopy (SEM) and deep ultraviolet (DUV) inspection tools. We observed that defects that appear to be opaque in the SEM can be highly transparent to EUV light, and inversely, defects that are mostly transparent to the SEM can be highly opaque to EUV. The nature and composition of these defects, whether they appear on the top surface, within the multilayer coating, or on the substrate as buried bumps or pits, influences both their significance when printed, and their detectability with the available techniques. Actinic inspection quantitatively predicts the characteristics of printed defect images in ways that may not be possible with non-EUV techniques. As a quantitative example, we investigate the main structural characteristics of a buried pit defect based on EUV through-focus imaging.

Aerosol indirect effects continue to constitute one of the most important uncertainties for anthropogenic climate perturbations. Within the international AEROCOM initiative, the representation of aerosol-cloud-radiation interactions in ten different general circulation models (GCMs) is evaluated using three satellite datasets. The focus is on stratiform liquid water clouds since most GCMs do not include ice nucleation effects, and none of the model explicitly parameterises aerosol effects on convective clouds. We compute statistical relationships between aerosol optical depth ({tau}{sub a}) and various cloud and radiation quantities in a manner that is consistent between the models and the satellite data. It is found that the model-simulated influence of aerosols on cloud droplet number concentration (N{sub d}) compares relatively well to the satellite data at least over the ocean. The relationship between {tau}{sub a} and liquid water path is simulated much too strongly by the models. This suggests that the implementation of the second aerosol indirect effect mainly in terms of an autoconversion parameterisation has to be revisited in the GCMs. A positive relationship between total cloud fraction (f{sub cld}) and {tau}{sub a} as found in the satellite data is simulated by the majority of the models, albeit less strongly than that in the …

The impact of carbon contamination on extreme ultraviolet (EUV) masks is significant due to throughput loss and potential effects on imaging performance. Current carbon contamination research primarily focuses on the lifetime of the multilayer surfaces, determined by reflectivity loss and reduced throughput in EUV exposure tools. However, contamination on patterned EUV masks can cause additional effects on absorbing features and the printed images, as well as impacting the efficiency of cleaning process. In this work, several different techniques were used to determine possible contamination topography. Lithographic simulations were also performed and the results compared with the experimental data.

In this study, multilayer morphology near the key anomalies in grating-like structures, namely sharp step-edges and steep walls, are examined. Different deposition schemes are employed. Based on cross section TEM analysis an explanatory model describing the morphology of the successive layers is developed. A further insight into the periodicity and the general performance of the multilayer is obtained by EUV microscopy. The main distortions in multilayer structure and hence EUV performance are found to be restricted to a region within a few hundred nanometers from the anomalies, which is very small compared to the proposed grating period (50-100 {micro}m). These multilayer coated blazed gratings can thus be considered a viable option for spectral purity enhancement of EUV light sources.

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This issue has the following articles: (1) Optimizing Electron-Positron Pair Production on kJ-Class High-Intensity Lasers for the Purpose of Pair-Plasma Creation; (2) Neutron Yield Study of Direct-Drive, Low-Adiabat Cryogenic D2 Implosions on OMEGA; (3) Al 1s-2p Absorption Spectroscopy of Shock-Wave Heating and Compression in Laser-Driven Planar Foil; (4) A Measurable Lawson Criterion and Hydro-Equivalent Curves for Inertial Confinement Fusion; (5) Pulsed-THz Characterization of Hg-Based, High-Temperature Superconductors; (6) LLE's Summer High School Research Program; (7) FY08 Laser Facility Report; and (8) National Laser Users Facility and External Users Programs.