Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies.

A recently developed coda magnitude methodology was applied to selected broadband stations in Turkey for the purpose of testing the coda method in a large, laterally complex region. As found in other, albeit smaller regions, coda envelope amplitude measurements are significantly less variable than distance-corrected direct wave measurements (i.e., L{sub g} and surface waves) by roughly a factor 3-to-4. Despite strong lateral crustal heterogeneity in Turkey, we found that the region could be adequately modeled assuming a simple 1-D, radially symmetric path correction for 10 narrow frequency bands ranging between 0.02 to 2.0 Hz. For higher frequencies however, 2-D path corrections will be necessary and will be the subject of a future study. After calibrating the stations ISP, ISKB, and MALT for local and regional distances, single-station moment-magnitude estimates (M{sub w}) derived from the coda spectra were in excellent agreement with those determined from multi-station waveform modeling inversions of long-period data, exhibiting a data standard deviation of 0.17. Though the calibration was validated using large events, the results of the calibration will extend M{sub w} estimates to significantly smaller events which could not otherwise be waveform modeled due to poor signal-to-noise ratio at long periods and sparse station coverage. The …

The mobilization of arsenic was examined in a system where the deposition of iron and arsenic have been substantially modified by large-scale manipulations. This engineering practice was designed to decrease arsenic concentrations in water supplied to the City of Los Angeles. Accomplishing this objective, however, has resulted in significant accumulation of arsenic and iron in the sediments of a reservoir on the Los Angeles Aqueduct. Arsenic and iron are released into the porewater at depth in the sediment, consistent with reductive dissolution of iron(III) oxyhydroxides. Factors influencing the possible re-sorption of arsenic onto residual iron(III) oxyhydroxides solids have been examined. Reduction of As(V) to As(III) alone cannot account for arsenic mobilization since arsenic occurs in the solid phase as As(III) well above the depth at which it is released into the porewater. Competition from other porewater constituents could suppress re-sorption of arsenic released by reductive dissolution.

A stable estimate of the earthquake source spectra in the western Alps is obtained using an empirical method based on coda envelope amplitude measurements described by Mayeda et al. (2003) for events ranging between M{sub W} {approx} 1.0 to {approx}5.0. We calibrated path corrections for consecutive narrow frequency bands ranging between 0.2 and 25.0-Hz using a simple 1-D model for 5 three-component stations of the Regional Seismic network of Northwestern Italy (RSNI). The 1-D assumption performs well, even though the region is characterized by a complex structural setting involving strong lateral variations in the Moho depth. For frequencies less than 1.0-Hz, we tied our dimensionless, distance-corrected coda amplitudes to an absolute scale in units of dyne-cm by using independent moment magnitudes from long-period waveform modeling for 3 moderate magnitude events in the region. For the higher frequencies, we used small events as empirical Green's functions, with corner frequencies above 25.0-Hz. For each station, the procedure yields frequency-dependent corrections that account for site effects, including those related to f{sub max}, as well as those related to S-to-coda transfer function effects. After the calibration was completed, the corrections were applied to the entire data-set composed of 957 events. Our findings using the …

In this paper we propose a novel visibility-culling technique for optimizing the computation and rendering of opaque isosurfaces. Given a continuous scalar field f (x) over a domain D and an isovalue w, our technique exploits the continuity of f to determine conservative visibility bounds implicitly, i.e., without the need for actually computing the isosurface f{sup -1}(w). We generate Implicit Occluders based on the change in sign of f *(x) = f (x)-w, from positive to negative (or vice versa) in the neighborhood of the isosurface. Consider, for example, the sign of f * along a ray r cast from the current viewpoint. The first change in sign of f * within D must contain an intersection of r with the isosurface. Any additional intersection of the isosurface with r is not visible. Implicit Occluders constitute a general concept that can be exploited algorithmically in different ways depending on the framework adopted for visibility computations. In this paper, we propose a simple from-point approach that exploits well-known hardware occlusion queries.

A Monte Carlo method for the estimation of {beta}-delayed {gamma}-ray spectra following fission is described that can accommodate an arbitrary time-dependent fission rate and photon collection history. The method invokes direct sampling of the independent fission yield distributions of the fissioning system, the branching ratios for decay of individual fission products and the spectral distributions for photon emission for each decay mode. Though computationally intensive, the method can provide a detailed estimate of the spectrum that would be recorded by an arbitrary spectrometer, and can prove useful in assessing the quality of evaluated data libraries, for identifying gaps in these libraries, etc. The method is illustrated by a first comparison of calculated and experimental spectra from decay of short-lived fission products following the reactions {sup 235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f). For general purpose transport calculations, where detailed consideration of the large number of individual {gamma}-ray transitions in a spectrum may be unnecessary, it is shown that an accurate and simple parameterization of a {gamma}-ray source function can be obtained. These parametrizations should provide high-quality average spectral distributions that should prove useful in calculations describing photons escaping from thick attenuating media.

The compressibility of fluid deuterium up to several Mbar has been probed using laser-driven shock waves reflected from a quartz anvil. Combining high-precision ({approx} 1 %) shock velocity measurements with the double-shock technique, where differences in equation of state (EOS) models are magnified, has allowed us to accurately discriminate between various theoretical predictions. Our data are consistent with EOS models that show approximately fourfold compression on the principal Hugoniot from 0.7 to 1 Mbar; however, our results indicate that deuterium has a higher compressibility than predicted by these models for single shock pressures between 1 and 2.5 Mbar.

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We calculate the atmospheric structure of an accretion disk around a Kerr black hole and obtain its X-ray spectrum, which exhibits prominent atomic transitions under certain circumstances. The gravitational and Doppler (red)shifts of the C V, C VI, O VII, O VIII, and Fe I-XXVI emission lines are observable in active galaxies. We quantify the line emissivities as a function of radius, to identify the effects of atmospheric structure, and to determine the usefulness of these lines for probing the disk energetics. The line emissivities do not always scale linearly with the incident radiative energy, as in the case of Fe XXV and Fe XXVI. Our model incorporates photoionization and thermal balance for the plasma, the hydrostatic approximation perpendicular to the plane of the disk, and general relativistic tidal forces. We include radiative recombination rates, fluorescence yields, Compton scattering, and photoelectric opacities for the most abundant elements.

The Material Control and Accountability (MC and A) Group has developed an electronic scan system to acknowledge issuance and returns of Tamper Indicating Device (TID) seals. Important MC and A features of the system are: 1. The system requires the issuer identification and the identification of applicators to be entered, thereby ensuring that at least two qualified issuers and applicators possess the seals. Also, Operations is prompted to ensure the Two Person Rule is met during issuance and application of the seals. 2. All input is date and time stamped to ease resolution of anomalies. 3. The system requires all information to be input before allowing the user to logoff, thereby eliminating the problem of incomplete information in the records. 4. The input is immediately available to FBL MC and A personnel outside the facility who then know to expect completed procedures and forms regarding these transactions. The paper will describe the application of these features in routine operations as well as the development effort and final configuration of the system.

Researchers at the Savannah River Technology Center (SRTC) successfully demonstrated the Caustic-Side Solvent Extraction (CSSX) process flow sheet using a 33-stage, 2-cm centrifugal contactor apparatus in two 24-hour tests using actual high level waste. Previously, we demonstrated the solvent extraction process with actual SRS HLW supernatant solution using a non-optimized solvent formulation. Following that test, the solvent system was optimized to enhance extractant solubility in the diluent by increasing the modifier concentration. We now report results of two tests with the new and optimized solvent.

We present deep Chandra and XMM-Newton observations of the galaxy cluster RDCS1252.9-2927, which was selected from the ROSAT Deep Cluster Survey (RDCS) and confirmed by extensive spectroscopy with the VLT at redshift z = 1.237. With the Chandra data, the X-ray emission from the intra-cluster medium is well resolved and traced out to 500 kpc, thus allowing a measurement of the physical properties of the gas with unprecedented accuracy at this redshift. We detect a clear 6.7 keV Iron K line in the Chandra spectrum providing a redshift within 1% of the spectroscopic one. By augmenting our spectroscopic analysis with the XMM-Newton data (MOS detectors only), we significantly narrow down the 1{sigma} error bar to 10% for the temperature and 30% for the metallicity, with best fit values kT = 6.0{sup +0.7}{sub -0.5} keV, Z = 0.36{sup +0.12}{sup -0.10}Z{sub {circle_dot}}. In the likely hypothesis of hydrostatic equilibrium, we measure a total mass of M{sub 500} = (1.9{+-}0.3)10{sup 14}h{sup -1}{sub 70} M{sub {circle_dot}} within R{sub {Delta}=500} {approx} 536 kpc. Overall, these observations imply that RDCS1252.9-2927 is the most X-ray luminous and likely the most massive bona-fide cluster discovered to date at z > 1. When combined with current samples of distant …

The redshift distribution of well-defined samples of distant early-type galaxies offers a means to test the predictions of monolithic and hierarchical galaxy formation scenarios. NICMOS maps of the entire Hubble Deep Field North in the F110W and F160W filters, when combined with the available WFPC2 data, allow us to calculate photometric redshifts and determine the morphological appearance of galaxies at rest-frame optical wavelengths out to z {approx} 2.5. Here we report results for two subsamples of early-type galaxies, defined primarily by their morphologies in the F160W band, which were selected from the NICMOS data down to H{sub 160AB} < 24.0. A primary subsample is defined as the 34 galaxies with early-type galaxy morphologies and early-type galaxy spectral energy distributions. The secondary subsample is defined as those 42 objects which have early-type galaxy morphologies with non-early type galaxy spectral energy distributions. The observed redshift distributions of our two early-type samples do not match that predicted by a monolithic collapse model, which shows an overabundance at z > 1.5. A (V/V{sub max}) test confirms this result. When the effects of passive luminosity evolution are included in the calculation, the mean value of Vmax for the primary sample is 0.22 {+-} 0.05, and …

The development of a viable hydrogen storage system is one of the key challenges that must be met prior to the establishment of a true hydrogen economy. Current hydrogen storage options, such as compressed gas and liquid hydrogen, fall short of meeting vehicle manufacturers' goals for safe and efficient energy storage. The most viable long-term alternative to these options is solid-state storage, which has been proven both safe and efficient. The Savannah River Technology Center (SRTC), with over 50 years of hydrogen storage expertise and over 25 years of expertise in solid-state storage, has assembled a world-class team to meet this key challenge. The SRTC team is comprised of distinguished scientists and engineers from national laboratories, leading universities, and major corporate research centers that are actively performing research in hydrogen storage on complex hydrides. Their collective expertise in materials development combined with fundamental science and systems engineering, will provide the synergy to meet the hydrogen storage goals. The team's goal is to develop a hydrogen storage system that meets the 2010 U.S. DOE targets, which includes a system with greater than 6 wt per cent hydrogen.

Growing interest and exploration dollars within the geothermal sector have paved the way for increasingly sophisticated suites of geophysical and geochemical tools and methodologies. The efforts to characterize and assess known geothermal fields and find new, previously unknown resources has been aided by the advent of higher spatial resolution airborne geophysics (e.g. aeromagnetics), development of new seismic processing techniques, and the genesis of modern multi-dimensional fluid flow and structural modeling algorithms, just to name a few. One of the newest techniques on the scene, is hyperspectral imaging. Really an optical analytical geochemical tool, hyperspectral imagers (or imaging spectrometers as they are also called), are generally flown at medium to high altitudes aboard mid-sized aircraft and much in the same way more familiar geophysics are flown. The hyperspectral data records a continuous spatial record of the earth's surface, as well as measuring a continuous spectral record of reflected sunlight or emitted thermal radiation. This high fidelity, uninterrupted spatial and spectral record allows for accurate material distribution mapping and quantitative identification at the pixel to sub-pixel level. In volcanic/geothermal regions, this capability translates to synoptic, high spatial resolution, large-area mineral maps generated at time scales conducive to both the faster pace of …

The production of large fluxes of pions and muons using high-energy, high-intensity proton pulses impinging on solid or liquid targets presents unique problems which have not yet been entirely solved. We investigate the possibilities of using solid targets by choosing a metal of either extremely low thermal expansion coefficient 1 or exceptionally high mechanical strength. Candidates are respectively Super-Invar and Vascomax 350 or Inconel 718. Moving targets in the form of chains or cables would be required for cooling purposes. These materials seem easily capable of surviving the beam pulses required for the largest beam power contemplated. Questions regarding radiation damage effects are being investigated.

We report measurements of the line polarization of Ne-like and F-like of iron n=3 to n=2 transitions in the x-ray region. We used the ''two-crystal technique'' developed in previous polarization measurements in our laboratory. Preliminary results from our measurements are presented together with the theoretical calculations using the Flexible Atomic Code (FAC). Our calculations show that contributions from cascades play an important role in the polarization calculations of most of the transitions. The uncertainties and difficulties of our experiments are also discussed.

We discuss particle tracking simulations in a storage ring with lithium lens inserts designed for the six-dimensional phase space cooling of muons by the ionization cooling. The ring design contains one or more lithium lens absorbers for transverse cooling that transmit the beam with very small beta-function values, in addition to liquid-hydrogen wedge-shaped absorbers in dispersive locations for longitudinal cooling. Such a ring could comprise the final component of a cooling system for use in a muon collider. The beam matching between dipole-quadrupole lattices and the lithium lenses is of particular interest.

In the unlikely event that CO2 leakage from deep geologic CO2 sequestration sites reaches the vadose zone, remediation measures for removing the CO2 gas plume may have to be undertaken. Carbon dioxide leakage plumes are similar in many ways to volatile organic compound (VOC) vapor plumes, and the same remediation approaches are applicable. We present here numerical simulation results of passive and active remediation strategies for CO2 leakage plumes in the vadose zone. The starting time for the remediation scenarios is assumed to be after a steady-state CO2 leakage plume is established in the vadose zone, and the source of this plume has been cut off. We consider first passive remediation, both with and without barometric pumping. Next, we consider active methods involving extraction wells in both vertical and horizontal configurations. To compare the effectiveness of the various remediation strategies, we define a half-life of the CO2 plume as a convenient measure of the CO2 removal rate. For CO2 removal by passive remediation approaches such as barometric pumping, thicker vadose zones generally require longer remediation times. However, for the case of a thin vadose zone where a significant fraction of the CO2 plume mass resides within the high liquid saturation …

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This paper describes an analytical technique developed to predict an order of magnitude volume of moisture accumulation in massive structures after deactivation. This work was done to support deactivation of a Department of Energy nuclear materials processing facility. The structure is a four-story, concrete building with a rectangular footprint that is approximately 250m long by 37m wide by 22m high. Its walls are 1.2m thick. The building will be supplied with unconditioned ventilation air after deactivation. The objective of the work was to provide a cost effective engineering evaluation to determine if the un-conditioned ventilation air would result in condensate accumulating inside the building under study. The analysis described is a simple representation of a complex problem. The modeling method is discussed in sufficient detail to allow its application to the study of similar structures.

The Analytical Development Section of Savannah River Technology Center (SRTC) was requested to determine the holdup of enriched uranium in a facility as part of an overall deactivation project of the facility. The facility was used to fabricate enriched uranium fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the production reactors. The results of the holdup assays are essential for determining compliance with the Waste Acceptance Criteria, Material Control and Accountability, and to meet criticality safety controls. This report covers calibration of the detectors in order to support holdup measurements in the out-gassing ovens. These ovens were used to remove gas entrained in billet assembly material prior to the billets being extruded into rods by the extrusion press. A portable high purity germanium detection system was used to determine highly enriched uranium (HEU) holdup and to determine holdup of U-235, Np-237, and Am-24 1 that were observed in these components. The detector system was run by an EG and G system that contains the high voltage power supply and signal processing electronics. A personal computer with Gamma-Vision software was used to control and provide space to store and manipulate multiple channel spectra. The measured Np-237 and Am-241 …

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

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