In this paper we discuss the experimental signatures of the new form of nuclear matter--the Color Glass Condensate (CGC) in particle production at RHIC. We show that predictions for particle production in p(d)A and AA collisions derived from these properties are in agreement with data collected at RHIC.

We report on 2D near-field imaging experiments of the 11.9-nm Sn X-ray laser that were performed with a set of novel Mo/Y multilayer mirrors having reflectivities of up to {approx}45% at normal and at 45 incidence. Second-moment analysis of the X-ray laser emission was used to determine values of the X-ray beam propagation factor M{sup 2} for a range of irradiation parameters. The results reveal a reduction of M{sup 2} with increasing prepulse amplitude. The spatial size of the output is a factor of {approx}2 smaller than previously measured for the 14.7-nm Pd X-ray laser, while the distance of the X-ray emission with respect to the target surface remains roughly the same.

As part of an effort to migrate the National Nuclear Data Center (NNDC) databases to a relational platform, a new web interface has been developed for the dissemination of the nuclear structure datasets stored in the Evaluated Nuclear Structure Data File and Experimental Unevaluated Nuclear Data List.

The usual approach to deal with noise present in many real-world optimization problems is to take an arbitrary number of samples of the objective function and use the sample average as an estimate of the true objective value. The number of samples is typically chosen arbitrarily and remains constant for the entire optimization process. This paper studies an adaptive sampling technique that varies the number of samples based on the uncertainty of deciding between two individuals. Experiments demonstrate the effect of adaptive sampling on the final solution quality reached by a genetic algorithm and the computational cost required to find the solution. The results suggest that the adaptive technique can effectively eliminate the need to set the sample size a priori, but in many cases it requires high computational costs.

For several decades, the Nuclear Science References database has been maintained as a tool for data evaluators and for the wider pure and applied research community. This contribution will describe the database and recent developments in web-based access.

Stray electrons can arise in positive-ion accelerators for heavy ion fusion or other applications as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary- electron emission. We summarize the distinguishing features of electron cloud issues in heavy-ion-fusion accelerators and a plan for developing a self-consistent simulation capability for heavy-ion beams and electron clouds. We also present results from several ingredients in this capability: (1) We calculate the electron cloud produced by electron desorption from computed beam-ion loss, which illustrates the importance of retaining ion reflection at the walls. (2) We simulate of the effect of specified electron cloud distributions on ion beam dynamics. We consider here electron distributions with axially varying density, centroid location, or radial shape, and examine both random and sinusoidally varying perturbations. We find that amplitude variations are most effective in spoiling ion beam quality, though for sinusoidal variations which match the natural ion beam centroid oscillation or breathing mode frequencies, the centroid and shape perturbations can also have significant impact. We identify an instability associated with a resonance between the beam-envelope ''breathing'' mode and the electron perturbation. We estimate its growth rate, which …

QR and LU factorizations for dense matrices are important linear algebra computations that are widely used in scientific applications. To efficiently perform these computations on modern computers, the factorization algorithms need to be blocked when operating on large matrices to effectively exploit the deep cache hierarchy prevalent in today's computer memory systems. Because both QR (based on Householder transformations) and LU factorization algorithms contain complex loop structures, few compilers can fully automate the blocking of these algorithms. Though linear algebra libraries such as LAPACK provides manually blocked implementations of these algorithms, by automatically generating blocked versions of the computations, more benefit can be gained such as automatic adaptation of different blocking strategies. This paper demonstrates how to apply an aggressive loop transformation technique, dependence hoisting, to produce efficient blockings for both QR and LU with partial pivoting. We present different blocking strategies that can be generated by our optimizer and compare the performance of auto-blocked versions with manually tuned versions in LAPACK, both using reference BLAS, ATLAS BLAS and native BLAS specially tuned for the underlying machine architectures.

The objective of this paper is to introduce the process and philosophies used to develop LLNL methodology for performing nonnuclear safety bases. Our former approach needed revision in order to implement the new Work Smart Standard (WSS), 'Safety Basis Requirements for Nonnuclear Facilities at Lawrence Livermore National Laboratory Site Specific Standard' (UCRL-ID-150214), approved in 2003 and revised January, 2004. This work relates directly to the following workshop theme: 'Improvements in Chemical, Biological, and Non-nuclear Safety analysis.' A requirements document, Environmental Safety and Health Manual, Document 3.1 provides safety bases methodology 'how-to' for LLNL personnel. This methodology document had to undergo a major revision, and essentially was completely re-written, since the nonnuclear requirements underwent a major change due to the new standard. The new methodology was based on a graded approach respective to risk level for each hazard type and facility classification. The development process included input from a cross-section of representatives of LLNL organizations at every step in the process. The initial methodology was tested in a pilot project that resulted in completed safety basis analyses and documentation for a major facility at LLNL. Feedback from the pilot was used to refine the methodology. The new methodology promotes a graded …

In an ongoing project to relate surface hydrothermal alteration to structurally controlled geothermal aquifers, we mapped a 16 km swath of the eastern front of the Stillwater Range using Hyperspectral fault and mineral mapping techniques. The Dixie Valley Fault system produces a large fractured aquifer heating Pleistocene aged groundwater to a temperature of 285 C at 5-6 km. Periodically over the last several thousand years, seismic events have pushed these heated fluids to the surface, leaving a rich history of hydrothermal alteration in the Stillwater Mountains. At Dixie Hot Springs, the potentiometric surface of the aquifer intersects the surface, and 75 C waters flow into the valley. We find a high concentration of alunite, kaolinite, and dickite on the exposed fault surface directly adjacent to a series of active fumaroles on the range front fault. This assemblage of minerals implies interaction with water in excess of 200 C. Field spectra support the location of the high temperature mineralization. Fault mapping using a Digital Elevation Model in combination with mineral lineation and field studies shows that complex fault interactions in this region are improving permeability in the region leading to unconfined fluid flow to the surface. Seismic studies conducted 10 km …

The early nonlinear phase of Rayleigh-Taylor growth is typically described in terms of the classic Layzer model in which bubbles of light fluid rise into the heavy fluid at a constant rate determined by the bubble radius and the gravitational acceleration. However, this model is strictly valid only for planar interfaces and hence ignores any effects which might be introduced by the spherically converging interfaces of interest in inertial confinement fusion. Here a generalization of the Layzer nonlinear bubble rise rate is given for a self-similar spherically converging flow of the type studied by Kidder. A simple formula for the bubble amplitude is found showing that, while the bubble initially rises with a constant velocity similar to the Layzer result, during the late phase of the implosion, an acceleration of the bubble rise rate occurs. The bubble rise rate is verified by comparison with numerical hydrodynamics simulations.

The Evaluated Nuclear Structure Data File (ENSDF) is a leading resource for the experimental nuclear data. It is maintained and distributed by the National Nuclear Data Center, Brookhaven National Laboratory. The file is mainly contributed to by an international network of evaluators under the auspice of the International Atomic Energy Agency. The ENSDF is updated, generally by mass number, i.e., evaluating together all isobars for a given mass number. If, however, experimental activity in an isobaric chain is limited to a particular nuclide then only that nuclide is updated. The evaluations are published in the journal Nuclear Data Sheets, Academic Press, a division of Elsevier.

A solid state electrochemical sensor has been developed for hydrogen leak detection in ambient air. The sensor uses an yttria-stabilized electrolyte with a tin-doped indium oxide sensing electrode and a Pt reference electrode. Excellent sensitivity, and response time of one second or less, are reported for hydrogen gas over the concentration range of 0.03 to 5.5% in air. Cross-sensitivity to relative humidity and to CO{sub 2} are shown to be low. The response to methane, a potentially significant source of interference for such a sensor, is significantly less than that for hydrogen. The sensor shows good reproducibility and was unaffected by thermal cycling over the course of this investigation. The effects of sensing electrode thickness and thermal aging are also reported, and the sensing mechanism is discussed. The sensor is intended for use in vehicles powered by hydrogen fuel cells and hydrogen internal combustion engines. Those vehicles will use and/or store significant quantities of hydrogen, and will require safety sensor for monitoring potential hydrogen leakage in order to ensure passenger safety.

An overview is given of measurements of the Fe K-shell spectrum from low-density laboratory sources. The measurements include wavelengths, electron-impact collision cross sections, innershell ionization phenomena, dielectronic recombination resonance strengths, charge exchange recombination, electron beam polarization effects, resonance excitation, and radiative cascade contributions. K-shell spectra have now also been obtained with microcalorimeters, including microcalorimeter arrays that are twins of the ASTRO-E and ASTRO-E2 missions, which illustrate typical resolving powers and spectral capabilities.

Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using x-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH{sub 4} by this method of exposure. In addition, x-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at. %-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl{sub 3} is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

Heulandite is a common rock-forming zeolite that exhibits wide solid solution of extra framework cations, presumably due to ready ion exchange with aqueous solutions. In order to provide a quantitative basis for interpreting and predicting the distribution of aqueous species between heulandite and aqueous solutions, ion exchange equilibrium between heulandite and aqueous solutions with respect to the binary cation pairs Ca{sup 2+} - K{sup +}, Ca{sup 2+} - Na{sup +}, K{sup +} - Na{sup +}, K{sup +} - Sr{sup 2+}, Na{sup +} - Sr{sup 2+}, and Ca{sup 2+} - Sr{sup 2+} was investigated. Homoionic Ca-, K-, and Na-heulandites prepared from natural heulandite were equilibrated with 0.1 N Cl{sup -} solutions containing various proportions of the cations in a given binary pair at 55 and 85 C to define isotherms describing partitioning of the cations over a wide range of heulandite and solution composition with respect to the cations in each pair. In general, the experiments equilibrated rapidly, within 11-15 weeks at 55 C and 3-4 weeks at 85 C. The exception was the Ca{sup 2+} - Sr{sup 2+} binary exchange, which did not equilibrate even after 3 months at 55 C and 4 weeks at 85 C. Slow exchange of …

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We introduce TLHaar, an n-bit to n-bit reversible transform similar to the S-transform. TLHaar uses lookup tables that approximate the S-transform, but reorder the coefficients so they fit into n bits. TLHaar is suited for lossless compression in fixed-width channels, such as digital video channels and graphics hardware frame buffers. Tests indicate that when the incoming image data has lines or hard edges TLHaar coefficients compress better than S-transform coefficients. For other types of image data TLHaar coefficients compress up to 2.5% worse than those of the S-transform, depending on the data and the compression method used.

In this paper we describe our approach to build a pipeline simulator for the future Large-scale Synoptic Survey Telescope (LSST). The simulated pipeline will be used to research and evaluate software architectures that are efficient and flexible. It will also be used to define the real-time software and hardware requirements needed to support the anticipated LSST data rates. The LSST data pipeline requirements are still being defined, however, previous surveys can provide a good source for data requirements. Our approach is to use the SuperMacho data pipeline as a prototyping tool to identify a framework for building Modular Data-Centric Pipeline (MDCP) architectures. The prototyping is done in a hierarchical fashion to help capture and define the general data attributes (schema) first. We then model other necessary components based on science and performance requirements. We use identified schemas or data attributes as a way to define a data model for LSST.

The Microsensors Program was born out the need for enhanced sensor technology in support of the Weapons Program. In the interest of expanded diagnostic capabilities to provide true performance characteristics of weapon assemblies in flight and ground tests, a suite of sensor requirements was proposed. These potential new sensor technologies were envisioned to be completely unobtrusive and allow for the development of test vehicles (mock warheads and bomb assemblies) that were designed to mechanical and electrical specifications as close to the stockpile weapon design configuration as possible. The closeness of a test vehicle design to the respective stockpile weapon design is referred to as ''fidelity,'' with the term ''high-fidelity'' to mean all components are designed to emulate, very closely, the true system design. These efforts were in line with many activities associated with Stockpile Stewardship and were intended to enable better modeling and performance assessment without the need for underground testing. Several weapons are currently undergoing Life Extension Programs (LEP) to lengthen each weapon system's respective service life. The ability to assess the projected life of these complex assemblies is crucial to the success of the LEP activities.

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Long-term cap rock integrity represents the single most important constraint on the long-term isolation performance of natural and engineered geologic CO{sub 2} storage sites. CO{sub 2} influx that forms natural accumulations and CO{sub 2} injection for EOR/sequestration or saline-aquifer disposal both lead to concomitant geochemical alteration and geomechanical deformation of the cap rock, enhancing or degrading its seal integrity depending on the relative effectiveness of these interdependent processes. This evolution of cap-rock permeability can be assessed through reactive transport modeling, an advanced computational method based on mathematical models of the coupled physical and chemical processes catalyzed by the influx event. Using our reactive transport simulator (NUFT), supporting geochemical databases and software (SUPCRT92), and distinct-element geomechanical model (LDEC), we have shown that influx-triggered mineral dissolution/precipitation reactions within typical shale cap rocks continuously reduce microfrac apertures, while pressure and effective-stress evolution first rapidly increase then slowly constrict them. For a given shale composition, the extent of geochemical enhancement is nearly independent of key reservoir properties (permeability and lateral continuity) that distinguish saline aquifer and EOR/sequestration settings and CO{sub 2} influx parameters (rate, focality, and duration) that distinguish engineered disposal sites and natural accumulations, because these characteristics and parameters have negligible impact on …

The ultimate fate of CO{sub 2} injected into saline aquifers for environmental isolation is governed by three interdependent yet conceptually distinct processes: CO{sub 2} migration as a buoyant immiscible fluid phase, direct chemical interaction of this rising plume with ambient saline waters, and its indirect chemical interaction with aquifer and cap-rock minerals through the aqueous wetting phase. Each process is directly linked to a corresponding trapping mechanism: immiscible plume migration to hydrodynamic trapping, plume-water interaction to solubility trapping, and plume-mineral interaction to mineral trapping. In this study, reactive transport modeling of CO{sub 2} storage in a shale-capped sandstone aquifer at Sleipner has elucidated and established key parametric dependencies of these fundamental processes, the associated trapping mechanisms, and sequestration partitioning among them during consecutive 10-year prograde (active-injection) and retrograde (post-injection) regimes. Intra-aquifer permeability structure controls the path of immiscible CO{sub 2} migration, thereby establishing the spatial framework of plume-aquifer interaction and the potential effectiveness of solubility and mineral trapping. Inter-bedded thin shales--which occur at Sleipner--retard vertical and promote lateral plume migration, thereby significantly expanding this framework and enhancing this potential. Actual efficacy of these trapping mechanisms is determined by compositional characteristics of the aquifer and cap rock: the degree of solubility …

We consider the two-dimensional Maxwell's equations in domains external to perfectly conducting objects of complex shape. The equations are discretized using a node-centered finite-difference scheme on a Cartesian grid and the boundary condition are discretized to second order accuracy employing an embedded technique which does not suffer from a ''small-cell'' time-step restriction in the explicit time-integration method. The computational domain is truncated by a perfectly matched layer (PML). We derive estimates for both the error due to reflections at the outer boundary of the PML, and due to discretizing the continuous PML equations. Using these estimates, we show how the parameters of the PML can be chosen to make the discrete solution of the PML equations converge to the solution of Maxwell's equations on the unbounded domain, as the grid size goes to zero. Several numerical examples are given.

This paper describes the development of an alternative technology for vehicular storage of hydrogen. Insulated pressure vessels are cryogenic-capable pressure vessels that can accept cryogenic liquid fuel, cryogenic compressed gas or compressed gas at ambient temperature. Insulated pressure vessels offer advantages over alternative hydrogen storage technologies. Insulated pressure vessels are more compact and less expensive than compressed hydrogen vessels. They have lower evaporative losses and lower energy requirement for fuel liquefaction than liquid hydrogen tanks, and they are lighter than hydrides. The work described in this paper is directed at verifying that insulated pressure vessels can be used safely for vehicular hydrogen storage. The paper describes multiple tests and analyses that have been conducted to evaluate the safety of insulated pressure vessels. Insulated pressure vessels have been subjected to multiple DOT, ISO and SAE certification tests, and the vessels have always been successful in meeting the passing criteria for the different tests. A draft procedure for insulated pressure vessel certification has been generated to assist in a future commercialization of this technology. Ongoing work includes the demonstration of this technology in a vehicle.