High-energy-density (HED) physics refers broadly to the study of macroscopic collections of matter under extreme conditions of temperature and density. The experimental facilities most widely used for these studies are high-power lasers and magnetic-pinch generators. The HED physics pursued on these facilities is still in its infancy, yet new regimes of experimental science are emerging. Examples from astrophysics include work relevant to planetary interiors, supernovae, astrophysical jets, and accreting compact objects (such as neutron stars and black holes). In this paper, we will review a selection of recent results in this new field of HED laboratory astrophysics and provide a brief look ahead to the coming decade.

The Bonneville Power Administration is proposing to fund the installation of a fenced stream crossing over the Pahsimeroi River to enhance a livestock riparian enclosure. This structure would include up to four wood fence posts and two deadman anchors buried in the ground. The goal of this project is to enhance salmon and steelhead rearing and migration habitat by preventing livestock from entering the riparian area via the river. The NEPA compliance checklist for this project was completed by Carl Rudeen with the Custer Soil and Water Conservation District (August 4, 2004) and meets the standards and guidelines for the Watershed Management Program Environmental Impact Statement (EIS) and Record of Decision (ROD). The Endangered Species Act (ESA) listed species that may occur in the general vicinity of the project area are gray wolf, Canada lynx, bald eagle, Ute ladies'Tresses, Snake River chinook salmon, Snake River steelhead trout, and Columbia River Basin bull trout. It was determined that the proposed fence crossing construction project would have no effect on these species. Bald eagle, gray wolf and Canada lynx are not known to occur in the immediate project vicinity. Since the site is used primarily as livestock pasture it does not lend …

Simulation of designs of an Integrated Beam Experiment (IBX) class accelerator have been carried out. These simulations are an important tool for validating such designs. Issues such as envelope mismatch and emittance growth can be examined in a self-consistent manner, including the details of injection, accelerator transitions, long-term transport, and longitudinal compression. The simulations are three-dimensional and time-dependent, and begin at the source. They continue up through the end of the acceleration region, at which point the data is passed on to a separate simulation of the drift compression. Results are be presented.

To avoid radiation damage, the acceptance of linear collider damping rings must be large enough that injection efficiency close to 100 percent can be achieved. Survival plots based on tracking particles in the NLC Main Damping Ring lattice suggest a dynamic aperture with some margin over the specified injected beam size and energy spread. Here, we apply Frequency Map Analysis to give a more detailed picture of the dynamical stability of particle trajectories in the presence of lattice nonlinearities arising from the sextupoles and the damping wiggler. The techniques that we use are of general applicability to nonlinear elements in beamlines, and in particular will be used for analysis of wiggler effects in future damping ring designs.

OAK-B135 Our BES funded research is aimed at determining structure(s) of model gas-phase ions and understanding how structure influences unimolecular reactivity. The model gas-phase ions include positional isomers of di- and tri-amino acids synthesized in my laboratory, i.e., RGG, GRG, and GGR, to peptides derived from proteolytic digestion of biologically relevant proteins. We are especially interested in understanding the role of intramolecular interactions in the stabilizing ion structure and how changing the charge-site affects structure. The location of charge of gas-phase ions can be manipulated by changing the position of the charge carrying amino acid (basic vs. acidic side chains) and by derivatization of the N- and/or C-terminus. For example, the proton of [M + H]+ ions is mobile and migrates over the entire molecule, whereas Li+, Na+, and to some extent K+ prefers to bind to the C-terminal or side-chain carboxylic acid groups, and Cu+ binds exclusively to the N-terminus and/or basic side-chains such as H, K, and R. The studies are carried out using tandem TOF mass spectrometry, viz. 193 nm (6.43 eV) photodissociation, low (Elab = 10-100 eV) and high kinetic energy (Elab = 1-10 keV) collision-induced dissociation (CID) and surface-induced dissociation (SID)(Elab = 20-70 eV). These …

The importance of developing higher-brightness electron beam sources for future accelerators was emphasized during the DOE-BESAC Subcommittee Meeting on the BES 20-Year Facility Roadmap held in Washington on February 20, 2003 [1]. The Subcommittee made a strong recommendation for an R&D program for high-brightness gun development. Spurred by this recommendation, a workshop was organized at Argonne National Laboratory on September 22-26, 2003 under the auspices of the ANL Theory Institute. About thirty experts in electron gun physics came for a week of intense discussion, reviewing the current state of the art and exploring ways to improve the performance of laser-driven rf photocathode guns, in particular whether an order of magnitude improvement of the beam brightness is feasible. Presentations given during the workshop can be found on the Internet at http://www.aps.anl.gov/asd/theory/presentations-online.html. This white paper grew out of the Argonne workshop. Its aim is to provide a summary of the ANL workshop and to propose an R&D program to develop advanced electron sources with an order of magnitude higher brightness than currently feasible. The budget for the R&D program for this purpose, discussed in Section 4, is estimated to be about $10M per year for ten years with an additional onetime start-up …

To address the need for real-time accurate total beryllium analyses, Savannah River Technology Center Analytical Development Section personnel evaluated and modified a colorimetric screening method developed at Los Alamos National Lab to measure beryllium on surfaces. This method was based on a color complex formed by beryllium and chromium azurol s . SRTC converted this visual method to a quantitative analysis method using spectrophotometric detection. The addition of a cationic surfactant (hexadecyltrimethylammonium bromide, CTAB) to the Be-CAS system shifted the complex absorbance away from the CAS absorbance and allowed for the detection. Assuming complete dissolution and a 10 mL rinse solution volume to remove the beryllium from the wipe, the detection limit was calculated comfortably below the free release limit. The spectrophotometric method was rugged and simple enough that it could be used as a field method.

The atomic scale structure of the 5-fold symmetric surface of an AlPdMn quasicrystal is investigated quantitatively by comparing x-ray photoelectron diffraction (XPD) simulations to experiment. The observed 5-fold symmetry of the diffraction patterns indicates that the surface is quasicrystalline with no hint of a reconstruction from the bulk structure. In analyzing the experimental data, many possible bulk terminations have been tested. Those few that fit best to the data have in common that they contain an Al-rich surface layer followed by a dense mixed Al/Pd/Mn layer. These best terminations, while not identical to each other, are suggested to form terraces coexisting on a real surface. Structural relaxations of the quasicrystal surface are also analyzed: mixing several best-fit terminations gives average best-fit interlayer spacing changes of Dd12 = -0.057 Angstrom, Dd24 = +0.159 Angstrom. These results are in good agreement with a prior structure determination by LEED on a sample that was prepared in a different manner.

Immobilization of toxic and radioactive metals in the vadose zone by In Situ Gaseous Reduction (ISGR) using hydrogen sulfide (H2S) is a promising technology for soil remediation. Earlier laboratory and field studies have shown that Cr(VI) can be effectively immobilized by treatment with dilute gaseous H2S. The objective of this project is to characterize the interactions among H2S, the metal contaminants, and soil components. Understanding these interactions is needed to assess the long-term effectiveness of the technology and to optimize the remediation system.

We sought to simulate auxetic behavior by carrying out dynamic analyses of mesoscopic model structures. We began by generating nearly periodic cellular structures. Four-node 'Shell' elements and eight-node 'Brick' elements are the basic building blocks for each cell. The shells and bricks obey standard elastic-plastic continuum mechanics. The dynamical response of the structures was next determined for a three-stage loading process: (1) homogeneous compression; (2) viscous relaxation; (3) uniaxial compression. The simulations were carried out with both serial and parallel computer codes--DYNA3D and ParaDyn--which describe the deformation of the shells and bricks with a robust contact algorithm. We summarize the results found here.

The Savannah River Site uses sophisticated glovebox facilities to process and analyze material that is radiologically contaminated or that must be protected from contamination by atmospheric gases. The analysis can be visual, non destructive measurement, or destructive measurement, and allows for the gathering of information that would otherwise not be obtainable. Macro and Micro systems that cover a range of 2X to 400X magnifications with a robust system compatible with the harsh glovebox environment were installed. Remote video inspection systems were developed and deployed in Savannah River Site glovebox facilities that provide high quality or mega-pixel quality remote views, for remote inspections. The specialized video systems that are the subject of this report exhibited specialized field application of remote video/viewing techniques by expanding remote viewing to high and very high quality viewing in gloveboxes. This technological enhancement will allow the gathering of precision information that is otherwise not available.

The temperature dependence of the photoluminescence (PL) transitions associated with various excitons and their phonon replicas in high-purity bulk ZnO has been studied at temperatures from 12 K to above room temperature (320 K). Several strong PL emission lines associated with LO phonon replicas of free and bound excitons are clearly observed. The room temperature PL spectrum is dominated by the phonon replicas of the free exciton transition with the maximum at the first LO phonon replica. The results explain the discrepancy between the transition energy of free exciton determined by reflection measurement and the peak position obtained by the PL measurement.