Modifications are described to upgrade the neutral-beam power supply for the TMX from 40 kV, 10 ms to 40 kV, 25 ms. The redesign of the accel and suppressor power supplies to achieve separation of the high-voltage and control sections, operation of the arc pulse lines in series, operation of the arc pulse lines in a noisy environment with SCR trigger and crowbar, and modifications to the electrolytic storage banks are discussed.

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Article on the dissociation of water on defective carbon substrates.

Article on collective polarization effects in β-polyvinylidene fluoride and its copolymers with tri- and tetrafluoroethylene.

To optimize the neutral-beam current incident on the fusion plasma and limit the heat load on exposed surfaces of the Mirror Fusion Test Facility magnet coils, impingement of the neutral beams on the magnet structure must be minimized. Also, placement of the neutral-beam injectors must comply with specifications for neutral-current heating of the plasma and should allow maximum flexibility to accommodate alternative beam aiming patterns without significant hardware replacement or experiment down-time. Injector placements and aimings are analyzed by means of the Structural Analysis Movie Post Processor (SAMPP), a general-purpose graphics code for the display of three-dimensional finite-element models. SAMPP is used to visually assemble, disassemble, or cut away sections of the complex three-dimensional apparatus, which is represented by an assemblage of 8-node solid finite elements. The resulting picture is used to detect and quantify interactions between the structure and the neutral-particle beams.

Uniformity of condensed layers of DT fuel in cryogenic ICF targets is a crucial parameter in their design. Measurements by classical interferometry lacks resolution to determine DT layer uniformity for targets with thick glass shells and/or thick ablative polymer coatings. We have developed holographic interferometry as an alternative tool for layer uniformity determination. This method is sensitive only to the fuel layer itself. We describe the technique and interference pattern analysis, and present preliminary results.

Low-k dielectric materials are becoming increasingly interesting as alternative to SiO2 with device geometries shrinking beyond the 65 nm technology node. At elevated temperatures hydrogen migration becomes an important degradation mechanism for conductivity breakdown in semiconductor devices. The possibility of hydrogen release during the fabrication process is, therefore, of great interest in the understanding of device reliability. In this study, various low-k dielectric films were subjected to thermal annealing at temperatures that are generally used for device fabrication. Elastic recoil detection analysis (ERDA) was used to investigate compositional changes and hydrogen redistribution in thin films of plasma-enhanced tetraethylortho-silicate (PETEOS), phosphorus doped silicon glass (PSG), silicon nitride (SiN) and silicon oxynitride (SiON). Except for an initial hydrogen release from the surface region in films of PETEOS and PSG, the results indicate that the elemental composition of the films was stable for at least 2 hours at 450◦C.

The Kapchinskij-Vladimirskij equations are widely used to study the evolution of the beam envelopes in a periodic system of quadrupole focusing cells. In this paper, we analyze the case of a matched beam. Our model is analogous to that used by Courant and Snyder [E.D. Courant and H.S. Snyder, Ann. Phys. 3, 1 (1958)]in obtaining a first-order approximate solution for a synchrotron. Here, we treat a linear machine and obtain an exact solution. The model uses a full occupancy, piecewise-constant focusing function and neglects space charge. There are solutions in an infinite number of bands as the focus strength is increased. We show that all these bands are stable. Our explicit results for the phase advance sigma and the envelope a(z) are exact for all phase advances except multiples of 180o, where the behavior is singular. We find that the peak envelope size is minimized at sigma = 90o. Actual operation in the higher bands would require very large, very accurate field strengths and would produce significantly larger envelope excursions.

The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider. For the reconstruction of charged particles, and their production and their decay vertices, ATLAS is equipped with a sophisticated tracking system, unprecedented in size and complexity. Full exploitation of both the Inner Detector and the muon spectrometer requires an accurate alignment. The challenge of aligning the ATLAS tracking devices is discussed, and the ATLAS alignment strategy is presented and illustrated with both data and Monte Carlo results.

The Mirror Fusion Test Facility (MFTF-B) is a large magnetic fusion energy experiment in the tandem mirror configuration. The requirement that each pair of Yin-Yang magnets, one pair at each end of the experiment, not undergo excessive lateral motion during seismic events was found to require excessively thick (> 12.7 mm) walled tubing in the support-struts, which accelerated the flow of heat inward to the 4 K magnet case from the nearby 300 K wall of the rector vessel, when any of the Cr-Ni austenite stainless steels, such as Type 304 with a 300 K yield-strength (sigma y) of 307 mpa (min.) was considered. Since the cold end of the lateral restraining strut was to be at or near 4 K, the additional constraints of good austenite stability and resistance to brittle fracture at 4 K existed. After consideration of these constraints against available information on Cr-Ni and Cr-Mn-Ni-N/sub 2/ austenitic stainless steels, grade XM-19 (Fe-22 Cr-12 Ni-5 Mn-.04 C-.02 N/sub 2/ was chosen. The mechanical properties of these welds were studied. (MOW)

Herbivores can gain indirect access to recalcitrant carbon present in plant cell walls through symbiotic associations with lignocellulolytic microbes. A paradigmatic example is the leaf-cutter ant (Tribe: Attini), which uses fresh leaves to cultivate a fungus for food in specialized gardens. Using a combination of sugar composition analyses, metagenomics, and whole-genome sequencing, we reveal that the fungus garden microbiome of leaf-cutter ants is composed of a diverse community of bacteria with high plant biomass-degrading capacity. Comparison of this microbiome?s predicted carbohydrate-degrading enzyme profile with other metagenomes shows closest similarity to the bovine rumen, indicating evolutionary convergence of plant biomass degrading potential between two important herbivorous animals. Genomic and physiological characterization of two dominant bacteria in the fungus garden microbiome provides evidence of their capacity to degrade cellulose. Given the recent interest in cellulosic biofuels, understanding how large-scale and rapid plant biomass degradation occurs in a highly evolved insect herbivore is of particular relevance for bioenergy.

Management of liquid water is critical for optimal fuel-cell operation, especially at low temperatures. It is therefore important to understand the wetting properties and water holdup of the various fuel-cell layers. While the gas-diffusion layer is relatively hydrophobic and exhibits a strong intermediate wettability, the catalyst layer is predominantly hydrophilic. In addition, the water content of the ionomer in the catalyst layer is lower than that of the bulk membrane, and is affected by platinum surfaces. Liquid-water removal occurs through droplets on the surface of the gas-diffusion layer. In order to predict droplet instability and detachment, a force balance is used. While the pressure or drag force on the droplet can be derived, the adhesion or surface-tension force requires measurement using a sliding-angle approach. It is shown that droplets produced by forcing water through the gas-diffusion layer rather than placing them on top of it show much stronger adhesion forces owing to the contact to the subsurface water.

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A new numerical solver for stiff transport predictions has been developed and implemented in the PTRANSP predictive transport code. The TGLF and GLF23 predictive codes have been incorporated in the solver, verified by comparisons with predictions from the XPTOR code, and validated by comparing predicted and measured profiles. Predictions for ITER baseline plasmas are presented.

The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Mouns, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muon is their short lifetime (2.1 microseconds at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As we see it now, high field superconducting solenoids are an integral part of a muon coUider muon production and cooling systems. This report will describe the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration.

These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Solid-state electrochemical sensors using two different sensing electrode compositions, gold and strontium-doped lanthanum manganite (LSM), were evaluated for gas phase sensing of NO{sub x} (NO and NO{sub 2}) using an impedance-metric technique. An asymmetric cell design utilizing porous YSZ electrolyte exposed both electrodes to the test gas (i.e., no reference gas). Sensitivity to less than 5 ppm NO and response/recovery times (10-90%) less than 10 s were demonstrated. Using an LSM sensing electrode, virtual identical sensitivity towards NO and NO{sub 2} was obtained, indicating that the equilibrium gas concentration was measured by the sensing electrode. In contrast, for cells employing a gold sensing electrode the NO{sub x} sensitivity varied depending on the cell design: increasing the amount of porous YSZ electrolyte on the sensor surface produced higher NO{sub 2} sensitivity compared to NO. In order to achieve comparable sensitivity for both NO and NO{sub 2}, the cell with the LSM sensing electrode required operation at a lower temperature (575 C) than the cell with the gold sensing electrode (650 C). The role of surface reactions are proposed to explain the differences in NO and NO{sub 2} selectivity using the two different electrode materials.

These proceedings contain papers prepared for the 25th Seismic Research Review -- Nuclear Explosion Monitoring: Building the Knowledge Base, held 23-25 September, 2003 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

A 20-month field study was conducted to measure the energy performance of south-facing large-area tungsten-oxide absorptive electrochromic (EC) windows with a broad switching range in a private office setting. The EC windows were controlled by a variety of means to bring in daylight while minimizing window glare. For some cases, a Venetian blind was coupled with the EC window to block direct sun. Some tests also involved dividing the EC window wall into zones where the upper EC zone was controlled to admit daylight while the lower zone was controlled to prevent glare yet permit view. If visual comfort requirements are addressed by EC control and Venetian blinds, a 2-zone EC window configuration provided average daily lighting energy savings of 10 {+-} 15% compared to the reference case with fully lowered Venetian blinds. Cooling load reductions were 0 {+-} 3%. If the reference case assumes no daylighting controls, lighting energy savings would be 44 {+-} 11%. Peak demand reductions due to window cooling load, given a critical demand-response mode, were 19-26% maximum on clear sunny days. Peak demand reductions in lighting energy use were 0% or 72-100% compared to a reference case with and without daylighting controls, respectively. Lighting energy …

The IAEA Marine Environment Laboratory (IAEA-MEL) in Monaco has conducted intercomparison exercises on radionuclides in marine samples for many years as part of its contribution to the IAEA's program of Analytical Quality Control Services (AQCS). An important part of the AQCS program has been a production of Reference Materials (RMs) and their provision to radioanalytical laboratories. The RMs have been developed for different marine matrices (sediment, water, biota), with accuracy and precision required for the present state of the art of radiometrics and mass spectrometry methods. The RMs have been produced as the final products of world-wide intercomparison exercises organized during last 30 years. A total of 44 intercomparison exercises were undertaken and 39 RMs were produced for radionuclides in the marine environment. All required matrices (seawater, biota, sediment) have been covered with radionuclide concentrations ranging from typical environmental levels to elevated levels affected by discharges from nuclear reprocessing plants. The long-term availability of RMs (over 10 years) requires the use of very specific techniques to collect and pretreat large quantities of material (e.g., in excess of 100 kg) in order to ensure sample stability and homogenization of any analytes of interest. The production of a RM is therefore a …

We have been developing a semiconductor Compton telescope to explore the universe in the energy band from several tens of keV to a few MeV. We use a Si strip and CdTe pixel detector for the Compton telescope to cover an energy range from 60 keV. For energies above several hundred keV, the higher efficiency of CdTe semiconductor in comparison with Si is expected to play an important role as an absorber and a scatterer. In order to demonstrate the spectral and imaging capability of a CdTe-based Compton Telescope, we have developed a Compton telescope consisting of a stack of CdTe pixel detectors as a small scale prototype. With this prototype, we succeeded in reconstructing images and spectra by solving the Compton equation from 122 keV to 662 keV. The energy resolution (FWHM) of reconstructed spectra is 7.3 keV at 511 keV and 3.1 keV at 122 keV, respectively. The angular resolution obtained at 511 keV is measured to be 12.2{sup o}(FWHM).

An explosive bonding procedure for joining 9.5 mm thick niobium plate to 203 mm thick 6061-T651 Al plate has been developed in order to maximize the bond tensile and impact strengths and the amount of bonded material across the surface of the plate. This procedure improves upon previous efforts, in which the 9.5 mm thick niobium plate is bonded directly to 6061-T4 Al plate. In this improved procedure, thin Nb and Al interlayers are explosively clad between the thicker niobium and aluminum plates. Bonds produced using these optimized parameters display a tensile strength of approximately 255 MPa and an impact strength per unit area of approximately 0.148 J/mm{sup 2}. Specialized mechanical testing geometries and procedures are required to measure these bond properties because of the unique bond geometry. In order to ensure that differences in the thermal expansion coefficients of aluminum and niobium do not adversely affect the bond strength, the effects of thermal cycling at temperatures between -22 C and 45 C on the mechanical properties of these bonds have also been investigated by testing samples in both the as-received and thermal cycled conditions. Based on the results obtained from this series of mechanical tests, thermal cycling is shown …

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A scheme for the solution of the time dependent Maxwell's equations on composite overlapping grids is described. The method uses high-order accurate approximations in space and time for Maxwell's equations written as a second-order vector wave equation. High-order accurate symmetric difference approximations to the generalized Laplace operator are constructed for curvilinear component grids. The modified equation approach is used to develop high-order accurate approximations that only use three time levels and have the same time-stepping restriction as the second-order scheme. Discrete boundary conditions for perfect electrical conductors and for material interfaces are developed and analyzed. The implementation is optimized for component grids that are Cartesian, resulting in a fast and efficient method. The solver runs on parallel machines with each component grid distributed across one or more processors. Numerical results in two- and three-dimensions are presented for the fourth-order accurate version of the method. These results demonstrate the accuracy and efficiency of the approach.