To significantly improve the simulation of climate by general circulation models (GCMs), systematic errors in representations of relevant processes must first be identified, and then reduced. This endeavor demands, in particular, that the GCM parameterizations of unresolved processes should be tested over a wide range of time scales, not just in climate simulations. Thus, a numerical weather prediction (NWP) methodology for evaluating model parameterizations and gaining insights into their behavior may prove useful, provied that suitable adaptations are made for implementation in climate GCMs. This method entails the generation of short-range weather forecasts by realistically initialized climate GCM, and the application of six-hourly NWP analyses and observations of parameterized variables to evaluate these forecasts. The behavior of the parameterizations in such a weather-forecasting framework can provide insights on how these schemes might be improved, and modified parameterizations then can be similarly tested. In order to further this method for evaluating and analyzing parameterizations in climate GCMs, the USDOE is funding a joint venture of its Climate Change Prediction Program (CCPP) and Atmospheric Radiation Measurement (ARM) Program: the CCPP-ARM Parameterization Testbed (CAPT). This article elaborates the scientific rationale for CAPT, discusses technical aspects of its methodology, and presents examples of its …

The US Enabling Technology Program in fusion is investigating the use of free flowing liquid surfaces facing the plasma. We have been studying the issues in integrating a liquid surface divertor into a configuration based upon an advanced tokamak, specifically the ARIES-RS configuration. The simplest form of such a divertor is to extend the flow of the liquid first wall into the divertor and thereby avoid introducing additional fluid streams. In this case, one can modify the flow above the divertor to enhance thermal mixing. For divertors with flowing liquid metals (or other electrically conductive fluids) MHD (magneto-hydrodynamics) effects are a major concern and can produce forces that redirect flow and suppress turbulence. An evaluation of Flibe (a molten salt) as a working fluid was done to assess a case in which the MHD forces could be largely neglected. Initial studies indicate that, for a tokamak with high power density, an integrated Flibe first wall and divertor does not seem workable. We have continued work with molten salts and replaced Flibe with Flinabe, a mixture of lithium and sodium fluorides, that has some potential because of its lower melting temperature. Sn and Sn-Li have also been considered, and the initial …

A numerical model of CO{sub 2} laser mitigation of damage growth in fused silica has been constructed that accounts for laser energy absorption, heat conduction, radiation transport, evaporation of fused silica and thermally induced stresses. This model will be used to understand scaling issues and effects of pulse and beam shapes on material removal, temperatures reached and stresses generated. Initial calculations show good agreement of simulated and measured material removal. The model has also been applied to LG-770 glass as a prototype red blocker material.

The effects of potential microbiologically influenced corrosion (MIC) on candidate packaging materials for nuclear waste containment are being assessed. Coupons of Alloy 22, the outer barrier candidate for waste packaging, were exposed to a simulated, saturated repository environment (or microcosm) consisting of crushed rock (tuff) from the Yucca Mountain repository site and a continual flow of simulated groundwater for periods up to five years at room temperature and 30 C. Coupons were incubated with YM tuff under both sterile and non-sterile conditions. Surfacial analysis by scanning electron microscopy of the biotically-incubated coupons show development of both submicron-sized pinholes and pores; these features were not present on either sterile or untreated control coupons. Room temperature, biotically-incubated coupons show a wide distribution of pores covering the coupon surface, while coupons incubated at 30 C show the pores restricted to polishing ridges.

C-terminal peptide thioesters are key intermediates for the synthesis/semisynthesis of proteins and for the production of cyclic peptides by native chemical ligation. They can be synthetically prepared by solid-phase peptide synthesis (SPPS) methods or biosynthetically by protein splicing techniques. Until recently, the chemical synthesis of C-terminal a-thioester peptides by SPPS was largely restricted to the Boc/Benzyl methodology because of the poor stability of the thioester bond to the basic conditions employed for the deprotection of the N{sup {alpha}}-Fmoc group. In the present work, we describe a new method for the SPPS of C-terminal thioesters by Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazide linker, which is totally stable to the Fmoc-SPPS conditions. Once the peptide synthesis has been completed, activation of the linker can be achieved by mild oxidation. This step transforms the hydrazide group into a highly reactive diazene intermediate which can react with different H-AA-SEt to yield the corresponding {alpha}-thioester peptide in good yields. This method has been successfully used for the generation of different thioester peptides, circular peptides and a fully functional SH3 protein domain.

This paper presents the experimental results of the third and final phase of a cookoff model validation effort. In this phase of the work, two generic Heavy Wall Penetrators (HWP) were tested in two heating orientations. Temperature and strain gage data were collected over the entire test period. Predictions for time and temperature of reaction were made prior to release of the live data. Predictions were comparable to the measured values and were highly dependent on the established boundary conditions. Both HWP tests failed at a weld located near the aft closure of the device. More than 90 percent of unreacted explosive was recovered in the end heated experiment and less than 30 percent recovered in the side heated test.

Precision spindles used for diamond turning and other applications requiring low error motion generally require a drive system that ideally applies a pure torque to the rotating spindle. Frequently a frameless motor, that is, one without its own bearings, is directly coupled to the spindle to make a compact and simple system having high resonant frequencies. Although in addition to delivering drive torque, asymmetries in the motor cause it to generate disturbance loads (forces and moments) which influence the spindle error motion of the directly coupled system. This paper describes the tests and results for a particular frameless, brushless DC motor that was originally developed for military and space applications requiring very low torque ripple. Because the construction of the motor should also lead to very low disturbance loads, it was selected for use on a new diamond turning and grinding machine under developed at Lawrence Livermore National Laboratory. The level of influence for this motor-spindle combination is expected to be of order one nanometer for radial and axial error motion.

Coherent scattering is a flavor-blind, high-rate, as yet undetected neutrino interaction predicted by the Standard Model. We propose to use a compact (kg-scale), two-phase (liquid-gas) argon ionization detector to measure coherent neutrino scattering off nuclei. In our approach, neutrino-induced nuclear recoils in the liquid produce a weak ionization signal, which is transported into a gas under the influence of an electric field, amplified via electroluminescence, and detected by phototubes or avalanche diodes. This paper describes the features of the detector, and estimates signal and background rates for a reactor neutrino source. Relatively compact detectors of this type, capable of detecting coherent scattering, offer a new approach to flavor-blind detection of man-made and astronomical neutrinos, and may allow development of compact neutrino detectors capable of nonintrusive real-time monitoring of fissile material in reactors.

Only the simplest monopole scattering behavior has usually been treated in previous time-reversal analyses. A new application of time-reversal processing of wave scattering data permits characterization of scatterers by analyzing the number and nature of the singular functions (or eigenfunctions) associated with individual scatterers when they have multiple contributions from monopole, dipole and/or quadrupole scattering terms. We discuss acoustic, elastic, and electromagnetic scattering problems for low frequencies (ka < 1, k being the wavenumber and a the radius of the scatterer). Specific examples for electromagnetic scattering from one of a number of small conducting spheres show that each sphere can have up to six distinct time-reversal eigenfunctions associated with it.

We present wavelength measurements of K-shell resonance lines of O V and O VI, using the University of California Lawrence Livermore National Laboratory EBIT-I electron beam ion trap. The wavelength accuracy of better than 140 ppm is sufficient to determine gas outflow velocities of warm absorbers associated with AGNs to within 40 km/s and better. Our measurements confirm that the outflow velocities associated with NGC 5548 and derived from O V and O VI lines are similar to those derived from the O VII lines. These kinematic measurements make for further evidence that the X-ray and UV absorbers in these systems are truly two manifestations of the same physical outflow.

We have cross-correlated MACHO LMC Cepheids with 2MASS Second Incremental Release Catalog. The resulting database is considerably larger than the set of OGLE Cepheids in the LMC bar, and has significantly better areal coverage, allowing more accurate determination of LMC geometry. Random-phase correction is applied to 2MASS J, H, and Ks magnitudes, using the knowledge of V-band light curve and the ephemeris of 2MASS observations, to produce mean magnitudes. The improvement of phase-corrected PL relations over random-phase PL relations is clearly demonstrated. Reddening is estimated for each star individually, further improving the accuracy of the method. The orientation parameters of the LMC are derived by a Maximum Likelihood approach which solves for viewing angles and PL coefficients simultaneously, providing an unbiased estimation. The results of the analysis are used to place limits on warping of the LMC disk. Implications for the microlensing optical depth are also discussed.

The utilization of nanomaterials in the synthesis and processing of energetic materials (i.e., pyrotechnics, explosives, and propellants) is a relatively new area of science and technology. Previous energetic nanomaterials have displayed new and potentially beneficial properties, relative to their conventional analogs. Unfortunately some of the energetic nanomaterials are difficult and or expensive to produce. At LLNL we are studying the application of sol-gel chemical methodology to the synthesis of energetic nanomaterials components and their formulation into energetic nanocomposites. Here sol-gel synthesis and formulation techniques are used to prepare Fe{sub 2}O{sub 3}/Al pyrotechnic nanocomposites. The preliminary characterization of their thermal properties and the degree of mixing between fuel and oxidizer phases is contrasted with that of a conventional pyrotechnic mixture.

Practical cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs, The ring modeled here uses realistic 3-dimensional fields and includes such ''real-world'' effects as windows on the absorbers and RF cavities and leaving empty lattice cells for injection and extraction. The ring increases the density of muons in a fixed acceptance volume by a factor of 4.2.

A new electromagnetic kinetic electron {delta} particle simulation model has been demonstrated to work well at large values of plasma {beta} times the ion-to-electron mass ratio. The simulation is three-dimensional using toroidal flux-tube geometry and includes electron-ion collisions. The model shows accurate shear Alfven wave damping and microtearing physics. Zonal flows with kinetic electrons are found to be turbulent with the spectrum peaking at zero and having a width in the frequency range of the driving turbulence. This is in contrast with adiabatic electron cases where the zonal flows are near stationary, even though the linear behavior of the zonal flow is not significantly affected by kinetic electrons. zonal fields are found to be very weak, consistent with theoretical predictions for {beta} below the kinetic ballooning limit. Detailed spectral analysis of the turbulence data is presented in the various limits.

We present an overview of computational techniques for simulating the thermal cookoff of high explosives using a multi-physics hydrodynamics code, ALE3D. Recent improvements to the code have aided our computational capability in modeling the response of energetic materials systems exposed to extreme thermal environments, such as fires. We consider an idealized model process for a confined explosive involving the transition from slow heating to rapid deflagration in which the time scale changes from days to hundreds of microseconds. The heating stage involves thermal expansion and decomposition according to an Arrhenius kinetics model while a pressure-dependent burn model is employed during the explosive phase. We describe and demonstrate the numerical strategies employed to make the transition from slow to fast dynamics. In addition, we investigate the sensitivity of wall expansion rates to numerical strategies and parameters. Results from a one-dimensional model show increased violence when the gap between the explosive and steel vessel is removed.

A process whereby laser-initiated surface damage on KDP/DKDP optics is removed by spot micro-machining using a high-speed drill and a single-crystal diamond bit, is shown to mitigate damage growth for subsequent laser shots. Our tests show that machined dimples on both surfaces of an AR coated doubler (KDP) crystal are stable, for 526nm, {approx} 3.2ns pulses at {approx} 12J/cm{sup 2} fluences. Other tests also confirmed that the machined dimples on both surfaces of an AR coated tripler (DKDP) crystal are stable, for 351nm, {approx} 3ns pulses at {approx} 8J/cm{sup 2}. We have demonstrated successful mitigation of laser-initiated surface damage sites as large as 0.14mm diameter on DKDP, for up to 1000 shots at 351nm, 13J/cm{sup 2}, {approx} 11ns pulse length, and up to 10 shots at 351nm, 8J/cm{sup 2}, 3ns. Details of the method are presented, including estimates for the heat generated during micro-machining and a plan to implement this method to treat pre-initiated or retrieved-from-service, large-scale optics for use in high-peak-power laser applications.

The effective lifetime of optics is limited by both laser-induced damage and the subsequent growth of laser initiated damage sites. We have measured the growth rate of laser-induced damage in fused silica in both air and vacuum at 527 nm. For damage on the exit surface, the data shows exponential growth in the lateral size of the damage site with shot number. The exponential growth coefficient depends linearly on the laser fluence. The behavior at the fluence threshold for growth is contrasted to that observed at 351 nm. The growth rate was not significantly affected by either the wavelength of the initiating fluence or the presence of 10 torr of air as compared to vacuum. When the damage is located on the input surface, it has both a higher threshold for growth and does not grow exponentially.

M-shell spectra of W ions have been produced at the Livermore EBIT-II electron beam ion trap at different energies of the electron beam. A survey has been performed for 2.4 keV, 2.8 keV, 3.6 keV and for steps in energy of 100 eV over the 3.9-4.6 keV energy range. The analysis of 11 W spectra has shown the presence of a wide variety of ionization stages from Se-like to Cr-like W; the appearances of these ionization stages correlate well with the energy of their production. The present paper focuses on the identification of 63 experimental features of W ions in a spectral region from 5 to 6 Angstrom using calculations with inclusion of all ionization stages matching this spectral region. The majority of lines in all spectra have been identified and assigned to the 4f {yields} 3d and 4d {yields} 3p transitions. This is the first work that lists a comprehensive identification of so many resolved spectral features of M-shell transitions in W ions recorded in such detail in the laboratory.

The authors present a new method for fast transport synthetic acceleration (TSA) of source iterations for S{sub N} problems, using a pure absorber problem stretched to have a mean free path comparable to a diffusion length. The resulting scheme is at first glance unstable, with a large negative eigenvalue at high spatial frequencies, but it can be made effective using (i) a low-pass filter, (ii) a Krylov method, or both. The stretched error correction and the filter are implemented with the same spatial discretization as the underlying source iteration, the Explicit Slope (ES) scheme. In this summary (Part I), they describe the acceleration method, summarize results of Fourier analysis, and give test results in homogeneous planar geometry. In the second summary, they describe significant additional features in heterogeneous problems.

To help capture valuable information on''green building'' case studies, the U.S. Department of Energy has created an online database for collecting, standardizing, and disseminating information about high-performance, green projects. Type of information collected includes green features, design processes, energy performance, and comparison to other high-performance, green buildings.

We have performed Photoelectron Spectroscopy and X-Ray Absorption Spectroscopy upon highly radioactive samples of Plutonium at the Advanced Light Source in Berkeley, CA, USA. First results from alpha and delta Plutonium are reported as well as plans for future studies of actinide studies.

The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 mm and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3{omega}) with a total intensity of 2 x 10{sup 15} W cm{sup -2}. The targets were filled with 1 atm of CO{sub 2} producing of up to 7 mm long homogeneously heated plasmas with densities of n{sub e} = 6 x 10{sup 20} cm{sup -3} and temperatures of T{sub e} = 2 keV. The high energy in a NIF quad of beams of 16kJ, illuminating the target from one direction, creates unique conditions for the study of laser plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last {approx}1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and …

The finite element method has been routinely used to calculate the image stresses of dislocation segments. When these segments intersect with surfaces, the image stresses at the surfaces diverges singularly. At the presence of these singularities, both convergence and accuracy of using the finite element method need to be examined critically. This article addresses these issues with the aim toward the application of dislocation dynamics simulations in thin films.

We have measured the equation of state (EoS) of osmium to 75 GPa under hydrostatic conditions at room temperature using angle dispersive x-ray diffraction. A least-squares fit of the data using a third order Birch-Murnaghan EoS yields K{sub 0} = 411 {+-} 6 GPa and K'{sub 0} = 4.0 {+-} 0.2, showing osmium is in fact more compressible than diamond. Most importantly, we have documented an anomaly in the compressibility at 20.3 GPa associated with a large discontinuity in the first pressure derivative of the c/a ratio. This discontinuity likely arises from the collapse of the small hole-ellipsoid in the Fermi surface near the L point. There has been much interest in the possibility of a Lifshitz [1] or electronic topological transition (ETT) in zinc at high-pressure near 10 GPa. Interestingly, while the experimental data remain somewhat ambiguous [2-5], most simulations suggest the ETT exists in this pressure range [6-8]. Recently, Steinle-Neumann et al. [8] have shown that the transition arises from changes in the band structure near the high-symmetry point K where three bands cross the Fermi surface upon compression. Thus one might expect that other hcp metals should exhibit similar phenomena. The hcp 4d and 5d transition elements …