We completed experiments in which we used a high-power laser to shock-melt a Bi(Zn) alloy and refreeze it in the shock release wave. We recovered the samples post shot for microscopic analysis and compared our results with the results from similar prior experiments with pure Bi. The targets in both sets of experiments were four-layer targets composed of BK7 glass, Al, the elemental Bi or Bi(Zn) alloy, and a transparent diagnostic window. There is conductive heating of the Bi through the Al layer from the hot plasma at the Al/BK7 boundary that depends on the Al thickness. Since the Bi(Zn) targets had a much thicker Al layer than did the Bi targets, the two sets of targets had somewhat different thermal histories even though they were driven to the same pressure. In this presentation we compare the resolidified Bi(Zn) microstructure to that of the Bi, accounting for the different thermal histories.

The branching fraction of the {tau}{sup -} {yields} 3h{sup -} 2h{sup +} {nu}{sub {tau}} decay (h = {pi}, K) is measured with the BABAR detector to be (8.56 {+-} 0.05 {+-} 0.42) x 10{sup -4}, where the first error is statistical and the second systematic. The observed structure of this decay is significantly different from the phase space prediction, with the {rho} resonance playing a strong role. The decay {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}}, with the f{sub 1}(1285) meson decaying to four charged pions, is observed and the branching fraction is measured to be (3.9 {+-} 0.7 {+-} 0.5) x 10{sup -4}.

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The KDP crystals present in the final optics assembly at the National Ignition Facility (NIF) are used for conversion of infrared laser light beam into ultraviolet. The conversion is highest for a certain incident angle, the alignment of which is determined from the position of the back reflection beam, which exhibits a distinct characteristics shape. When a phase plate device is introduced before the final assembly to increase the uniformity of the beam, the back reflection pattern changes drastically. The algorithm which is best for tracking the special shaped beam is no longer suitable to track the phase modified beam. The work presented here discusses our detection schemes for both the situations. In particular, we demonstrate how the algorithm senses the modified beam using a newly proposed criterion of ''correlation peak pedestal area'' and execute an alternate algorithm in real time without operator intervention. This new algorithm continuously tracks the beam pattern to guarantee reliable and repeatable sensing. Results from simulation and real world implementation of the algorithm at the NIF facility are presented.

We have studied pressure-induced chemical reactions in carbon monoxide using both a diamond-anvil cell and a modified large volume press. Our spectroscopic data reveal that carbon monoxide disproportionates into molecular CO{sub 2} and a solid lactone-type polymer; photochemically above 3.2 GPa, thermochemically above 5 GPa at 300K, or at 3 GPa and {approx}2000K as achieved by laser heating. The solid product can be recovered at ambient conditions with a high degree of conversion, measured to be up to 95% of the original CO. Its fundamental chemical structure includes {beta}-lactone and conjugated C=C, which can be considered a severely modified polymeric carbon suboxide with open ladders and smaller five-membered rings. The polymer is metastable at ambient conditions, spontaneously liberating CO{sub 2} gases exothermically. We find that the recovered polymer has a high energy density, 1-8 KJ/g, and is very combustible. We estimate the density of recovered CO polymer to be at least 1.65 g/cm cm{sup 3}.

We provide a systematic analysis of nonnegative matrix factorization (NMF) relating to data clustering. We generalize the usual X = FG{sup T} decomposition to the symmetric W = HH{sup T} and W = HSH{sup T} decompositions. We show that (1) W = HH{sup T} is equivalent to Kernel K-means clustering and the Laplacian-based spectral clustering. (2) X = FG{sup T} is equivalent to simultaneous clustering of rows and columns of a bipartite graph. We emphasizes the importance of orthogonality in NMF and soft clustering nature of NMF. These results are verified with experiments on face images and newsgroups.

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The equatorial Pacific is a region with strong negative feedbacks. Yet coupled GCMs have exhibited a propensity to develop a significant SST bias in that region, suggesting an unrealistic sensitivity in the coupled models to small energy flux errors that inevitably occur in the individual model components. Could this 'hypersensitivity' exhibited in a coupled model be due to an underestimate of the strength of the negative feedbacks in this region? With this suspicion, the feedbacks in the equatorial Pacific in seven atmospheric GCMs (AGCMs) have been quantified using the interannual variations in that region and compared with the corresponding calculations from the observations. The seven AGCMs are: the NCAR CAM1, the NCAR CAM2,the NCAR CAM3, the NASA/NSIPP Atmospheric Model, the Hadley Center Model, the GFDL AM2p10, and the GFDL AM2p12. All the corresponding coupled runs of these seven AGCMs have an excessive cold-tongue in the equatorial Pacific. The net atmospheric feedback over the equatorial Pacific in the two GFDL models is found to be comparable to the observed value. All other models are found to have a weaker negative net feedback from the atmosphere--a weaker regulating effect on the underlying SST than the real atmosphere. A weaker negative feedback from …

Increasingly, ADC technology is being pressed into service for single single-shot instrumentation applications that were formerly served by vacuum-tube based oscilloscopes and streak cameras. ADC technology, while convenient, suffers significant performance impairments. Thus, in these demanding applications, a quantitative and accurate representation of these impairments is critical to an understanding of measurement accuracy. We have developed a phase-plane behavioral model, implemented it in SIMULINK and applied it to interleaved, high-speed ADCs (up to 4 gigasamples/sec). We have also developed and demonstrated techniques to effectively compensate for these impairments based upon the model.

Alloy 22 (N06022) is a nickel based alloy containing alloying elements such as chromium, molybdenum and tungsten. It is highly corrosion resistant both under reducing and under oxidizing conditions. Electrochemical studies such as electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 in 1M NaCl solutions at various pH values from acidic to neutral at 90 C. Tests were also carried out in NaCl solutions containing oxalic acid or acetic acid. It is shown that the corrosion rate of Alloy 22 was higher in a solution containing oxalic acid than in a solution of the same pH acidified with HCl. Acetic acid was not corrosive to Alloy 22. The corrosivity of oxalic acid was attributed to its capacity to form stable complex species with metallic cations from Alloy 22.

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{sup 137}Cs transfer factors were computed for small mammals collected from the dried sediment areas of a partially drained, contaminated reservoir. Soil {sup 137}Cs concentrations were heterogeneous on small and large spatial scales, with a geometric mean of 253.1 Bq/kg dry weight. About 50% of the variance in cotton rat Sigmodon hispidus tissue {sup 137}Cs levels was explained by variation in soil {sup 137}Cs levels. Soil to animal transfer factors (whole body dry weight) averaged 6.0 for cotton rats and 1.2 for cotton mice Peromyscus gossypinus. These values are similar to {sup 137}Cs transfer factors for herbivorous, homeothermic animals from other contaminated ecosystems. Site-specific transfer factors can significantly affect the estimation of dose. In the RESRAD-BIOTA dose model, the default transfer factor for {sup 137}Cs in terrestrial animals is 110 resulting in an estimate of radiation dose to terrestrial biota that is 16 times more than the dose calculated with the actual measured transfer factor.

This article reviews some design considerations for the scaling down in size of instruments and machines with a primary aim to identify technologies that may provide more optimal performance solutions than those, often established, technologies used at macroscopic, or conventional, scales. Dimensional metrology within emerging applications will be considered for meso- through micro-down to nanometer level systems with particular emphasis on systems for which precision is directly related to function. In this paper, attention is limited to some of the more fundamental issues associated with scaling. For example, actuator work or power densities or the effect of noise on the sensor signals can be readily evaluated and provide some guidance in the selection for any given size of device. However, with reductions in scale these parameters and/or phenomena that limit performance may change. Within this review, the authors have tried to assess these complex inter-relationships between performance and scale, again from a fundamental perspective. In practice, it is likely that the nuances of implementation and integration of sensor, actuator and/or mechanism designs will determine functionality and commercial viability of any particular system development.

The Soft Gamma-ray Detector (SGD) on board NeXT (Japanese future high energy astrophysics mission) is a Compton telescope with narrow field of view, which utilizes Compton kinematics to enhance its background rejection capabilities. It is realized as a hybrid semiconductor gamma-ray detector which consists of silicon and Cadmium Telluride (CdTe) detectors. It can detect photons in an energy band 0.05-1 MeV at a background level of 5 x 10{sup -7} counts/s/cm{sup 2}/keV; the silicon layers are required to improve the performance at a lower energy band (<0.3 MeV). Excellent energy resolution is the key feature of the SGD to achieve both high angular resolution and good background rejection capability. Its ability to measure gamma-ray polarization opens up a new window to study gamma-ray emission in the universe. We will present the development of key technologies to realize the SGD; high quality CdTe, low noise front-end VLSI and bump bonding technology. Energy resolutions of 1.7 keV (FWHM) for CdTe pixel detectors and 1.1 keV for silicon strip detectors have been measured. We also present the validation of Monte Carlo simulation used to evaluate the performance of the SGD.

The International Linear Collider based on superconducting RF cavities requires the damping rings to have extremely small equilibrium emittance, huge circumference, fast damping time, and large acceptance. To achieve all of these requirements is a very challenging task. In this paper, we will present a systematic approach to designing the damping rings using simple cells and non-interlaced sextupoles. The designs of the damping rings with various circumferences and shapes, including dogbone, are presented. To model realistic wigglers, we have developed a new hybrid symplectic integrator for faster and accurate evaluation of dynamic aperture of the lattices.

We present preliminary measurements of branching fractions and direct CP violating asymmetries in charmless two-body B decays, obtained with the BABAR detector using a sample of 227M {Upsilon}(4S) {yields} B{bar B} decays. We report the first observation of B{sup 0} {yields} K{sup 0}{bar K}{sup 0} and the first observation of direct CP violation in B{sup 0} {yields} K{sup +}{pi}{sup -} decays.

One of the outstanding unsolved riddles of nuclear astrophysics is the origin of the so called ''p-process'' nuclei from A = 92 to 126. Both the lighter and heavier p-process nuclei are adequately produced in the neon and oxygen shells of ordinary Type II supernovae, but the origin of these intermediate isotopes, especially {sup 92,94}Mo and {sup 96,98}Ru, has long been mysterious. Here we explore the production of these nuclei in the neutrino-driven wind from a young neutron star. We consider such early times that the wind still contains a proton excess because the rates for {nu}{sub e} and positron captures on neutrons are faster than those for the inverse captures on protons. Following a suggestion by Froehlich et al. (2005), they also include the possibility that, in addition to the protons, {alpha}-particles, and heavy seed, a small flux of neutrons is maintained by the reaction p({bar {nu}}{sub e}, e{sup +})n. This flux of neutrons is critical in bridging the long waiting points along the path of the rp-process by (n,p) and (n,{gamma}) reactions. Using the unmodified ejecta histories from a recent two-dimensional supernova model by Janka, Buras, and Rampp (2003), they find synthesis of p-rich nuclei up to {sup …

Soils from many industrial sites in southeastern USA arecontaminated with As because of the application of herbicide containingAs2O3. Among those contaminated sites, two industrial sites, FW and BH,which are currently active and of most serious environmental concerns,were selected to characterize the occurrence of As in the contaminatedsoils and to evaluate its environmental leachability. The soils are bothsandy loams with varying mineralogical and organic matter contents.Microwave-assisted acid digestion (EPA method 3051) of the contaminatedsoils indicated As levels of up to 325 mg/kg and 900 mg/kg (dry weightbasis) for FW and BH soils, respectively. However, bulk X-ray powderdiffraction (XRD) analysis failed to find any detectable As-bearingphases in either of the studied soil samples. Most of the soil As wasobserved by scanning electron microscopy, coupled with energy dispersiveX-ray spectroscopy (SEM/EDX), to be disseminated on the surfaces offine-grained soil particles in close association with Al and Fe. A fewAs-bearing particles were detected in BH soil using electron microprobeanalysis (EMPA). Synchrotron micro-XRD and X-ray absorption near-edgestructure (XANES) analyses indicated that these As-rich particles werepossibly phaunouxite, a mineral similar to calcium arsenate, which couldhave been formed by natural weathering after the application of As2O3.However, the scarcity of those particles eliminated them from playing anyimportant role in …

The preequilibrium reaction mechanism makes an important contribution to neutron-induced reactions above E{sub n} {approx} 10 MeV. The preequilibrium process has been studied exclusively via the characteristic high energy neutrons produced at bombarding energies greater than 10 MeV. They are expanding the study of the preequilibrium reaction mechanism through {gamma}-ray spectroscopy. Cross-section measurements were made of prompt {gamma}-ray production as a function of incident neutron energy (E{sub n} = 1 to 250 MeV) on a {sup 48}Ti sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center facility. The prompt-reaction {gamma} rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Residual state population was predicted using the GNASH reaction code, enhanced for preequilibrium. The preequilibrium reaction spin distribution was calculated using the quantum mechanical theory of Feshback, Kerman, and Koonin (FKK). The multistep direct part of the FKK theory was calculated for a one-step process. …

The most important requirement for high-level waste glass acceptance for disposal in a geological repository is the chemical durability, expressed as a glass dissolution rate. During the early stages of glass dissolution in near static conditions that represent a repository disposal environment, a gel layer resembling a membrane forms on the glass surface through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer has been found to age into either clay mineral assemblages or zeolite mineral assemblages. The formation of one phase preferentially over the other has been experimentally related to changes in the pH of the leachant and related to the relative amounts of Al{sup +3} and Fe{sup +3} in a glass. The formation of clay mineral assemblages on the leached glass surface layers ,lower pH and Fe{sup +3} rich glasses, causes the dissolution rate to slow to a long-term steady state rate. The formation of zeolite mineral assemblages ,higher pH and Al{sup +3} rich glasses, on leached glass surface layers causes the dissolution rate to increase and return to the initial high …

We present results of a simulation of 2 flavour QCD on a 16{sup 3} x 4 lattice using p4-improved staggered fermions with bare quark mass m/T = 0.4. Derivatives of the thermodynamic grand canonical partition function Z(V,T,{mu}{sub u},{mu}{sub d}) with respect to chemical potentials {mu}{sub u,d} for different quark flavours are calculated up to sixth order, enabling estimates of the pressure and the quark number density as well as the chiral condensate and various susceptibilities as functions of {mu}{sub u,d} via Taylor series expansion. Results are compared to high temperature perturbation theory as well as a hadron resonance gas model. We also analyze baryon as well as isospin fluctuations and discuss the relation to the chiral critical point in the QCD phase diagram. We moreover discuss the dependence of the heavy quark free energy on the chemical potential.

NSLS booster diagnostics consisted of tune measurement system, system for turn-by-turn measurement on the electron beam, and beam intensity monitor, which is not absolutely calibrated. We present design and implementation of synchrotron light monitor for the booster, which expands diagnostics capabilities. The system allows to measure an orbit, beam sizes and coupling of the electron beam along the ramp.

One way to reduce the computational cost of electronic structure calculations is to employ auxiliary basis expansions to approximate 4 center integrals in terms of 2 and 3-center integrals, usually using the variationally optimum Coulomb metric to determine the expansion coefficients. However the long-range decay behavior of the auxiliary basis expansion coefficients has not been characterized. We find that this decay can be surprisingly slow. Numerical experiments on linear alkanes and a toy model both show that the decay can be as slow as 1/r in the distance between the auxiliary function and the fitted charge distribution. The Coulomb metric fitting equations also involve divergent matrix elements for extended systems treated with periodic boundary conditions. An attenuated Coulomb metric that is short-range can eliminate these oddities without substantially degrading calculated relative energies. The sparsity of the fit coefficients is assessed on simple hydrocarbon molecules, and shows quite early onset of linear growth in the number of significant coefficients with system size using the attenuated Coulomb metric. This means it is possible to design linear scaling auxiliary basis methods without additional approximations to treat large systems.

We examine the violation of the k{sub {perpendicular}}factorization approximation for quark production in high energy proton-nucleus collisions. We comment on its implications for the open charm and quarkonium production in collider experiments.