An Alternative Model for Electron Correlation in Pu (open access)

An Alternative Model for Electron Correlation in Pu

Using a density functional theory based approach that treats the 5f electrons relativistically, a Pu electronic structure with zero net magnetic moment is obtained, where the 5f orbital and 5f spin moments cancel each other. By combining the spin and orbital specific densities of states with state, spin and polarization specific transition moments, it is possible to reconstruct the experimentally observed photoemission spectra from Pu. Extrapolating to a spin-resolving Fano configuration, it is shown how this would resolve the extant controversy over Pu electronic structure.
Date: October 23, 2007
Creator: Yu, S.; Tobin, J. & Soderlind, P.
Object Type: Article
System: The UNT Digital Library
Columbia River Component Data Gap Analysis (open access)

Columbia River Component Data Gap Analysis

This Data Gap Analysis report documents the results of a study conducted by Washington Closure Hanford (WCH) to compile and reivew the currently available surface water and sediment data for the Columbia River near and downstream of the Hanford Site. This Data Gap Analysis study was conducted to review the adequacy of the existing surface water and sediment data set from the Columbia River, with specific reference to the use of the data in future site characterization and screening level risk assessments.
Date: October 23, 2007
Creator: Hulstrom, L. C.
Object Type: Report
System: The UNT Digital Library
D0 - Anti-D0 Mixing at BaBar (open access)

D0 - Anti-D0 Mixing at BaBar

The BABAR and Belle collaborations have recently found evidence for mixing within the D meson system. We present some of the mixing search techniques used by BABAR and their status as of the beginning of the summer 2007. These have culminated in a measurement in the K{pi} decay final state of the D that is inconsistent with the no-mixing hypothesis with a significance of 3.9 standard deviations.
Date: October 23, 2007
Creator: Seiden, A. & /UC, Santa Cruz
Object Type: Article
System: The UNT Digital Library
Extremely Fast Acceleration of Cosmic Rays in a Supernova Remnant (open access)

Extremely Fast Acceleration of Cosmic Rays in a Supernova Remnant

Galactic cosmic rays (CRs) are widely believed to be accelerated by shock waves associated with the expansion of supernova ejecta into the interstellar medium. A key issue in this long-standing conjecture is a theoretical prediction that the interstellar magnetic field can be substantially amplified at the shock of a young supernova remnant (SNR) through magnetohydrodynamic waves generated by cosmic rays. Here we report a discovery of the brightening and decay of X-ray hot spots in the shell of theSNRRXJ1713.723946 on a one-year timescale. This rapid variability shows that the X-rays are produced by ultrarelativistic electrons through a synchrotron process and that electron acceleration does indeed take place in a strongly magnetized environment, indicating amplification of the magnetic field by a factor of more than 100. The X-ray variability also implies that we have witnessed the ongoing shock-acceleration of electrons in real time. Independently, broadband X-ray spectrometric measurements of RXJ1713.723946 indicate that electron acceleration proceeds in the most effective ('Bohm-diffusion') regime. Taken together, these two results provide a strong argument for acceleration of protons and nuclei to energies of 1 PeV (10{sup 15} eV) and beyond in young supernova remnants.
Date: October 23, 2007
Creator: Uchiyama, Y.; Aharonian, F. A.; Tanaka, T.; Takahashi, T. & Maeda, Y.
Object Type: Article
System: The UNT Digital Library
Final optics damage inspection (FODI) for the National Ignition Facility (open access)

Final optics damage inspection (FODI) for the National Ignition Facility

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) will routinely fire high energy shots (approaching 10 kJ per beamline) through the final optics, located on the target chamber. After a high fluence shot, exceeding 4J/cm2 at 351 nm wavelength, the final optics will be inspected for laser-induced damage. The FODI (Final Optics Damage Inspection) system has been developed for this purpose, with requirements to detect laser-induced damage initiation and to track and size it's the growth to the point at which the optic is removed and the site mitigated. The FODI system is the 'corner stone' of the NIF optic recycle strategy. We will describe the FODI system and discuss the challenges to make optics inspection a routine part of NIF operations.
Date: October 23, 2007
Creator: Conder, A.; Alger, T.; Azevedo, S.; Chang, J.; Glenn, S.; Kegelmeyer, L. et al.
Object Type: Article
System: The UNT Digital Library
Genus Oblivious Cross Parameterization: Robust Topological Management of Inter-surface Maps (open access)

Genus Oblivious Cross Parameterization: Robust Topological Management of Inter-surface Maps

We consider the problem of generating a map between two triangulated meshes, M and M{prime}, with arbitrary and possibly differing genus. This problem has rarely been tackled in its generality. Early schemes considered only topological spheres. Recent algorithms allow inputs with an arbitrary number of tunnels but require M and M{prime} to have equal genus, mapping tunnel to tunnel. Other schemes which allow more general inputs are not guaranteed to work and the authors do not provide a characterization of the input meshes that can be processed successfully. Moreover, the techniques have difficulty dealing with coarse meshes with many tunnels. In this paper we present the first robust approach to build a map between two meshes of arbitrary unequal genus. We also provide a simplified method for setting the initial alignment between M and M{prime}, reducing reliance on landmarks and allowing the user to select 'landmark tunnels' in addition to the standard landmark vertices. After computing the map, we automatically derive a continuous deformation from M to M{prime} using a variational implicit approach to describe the evolution of non-landmark tunnels. Overall, we achieve a cross parameterization scheme that is provably robust in the sense that it can map M to …
Date: October 23, 2007
Creator: Bennett, J C; Pascucci, V & Joy, K I
Object Type: Article
System: The UNT Digital Library
Hanford Site Near-Facility Environmental Monitoring Data Report for Calendar Year 2006 (open access)

Hanford Site Near-Facility Environmental Monitoring Data Report for Calendar Year 2006

This document contains brief discussions, specific sampling location information, and complete analytical data for Hanford Site near-facility environmental monitoring efforts in 2006.
Date: October 23, 2007
Creator: Perkins, Craig J.; Dorsey, Michael C.; Mckinney, Stephen M. & Roos, Richard C.
Object Type: Report
System: The UNT Digital Library
PERFORMANCE TESTING OF SPRING ENERGIZED C-RINGS FOR USE IN RADIOACTIVE MATERIAL PACKAGINGS CONTAINING TRITIUM (open access)

PERFORMANCE TESTING OF SPRING ENERGIZED C-RINGS FOR USE IN RADIOACTIVE MATERIAL PACKAGINGS CONTAINING TRITIUM

This paper describes the sealing performance testing and results of silver-plated inconel Spring Energized C-Rings used for tritium containment in radioactive shipping packagings. The test methodology used follows requirements of the American Society of Mechanical Engineers (ASME) summarized in ASME Pressure Vessel Code (B&PVC), Section V, Article 10, Appendix IX (Helium Mass Spectrometer Test - Hood Technique) and recommendations by the American National Standards Institute (ANSI) described in ANSI N14.5-1997. The tests parameters bound the predicted structural and thermal responses from conditions defined in the Code of Federal Regulations 10 CFR 71. The testing includes an evaluation of the effects of pressure, temperature, flange deflection, surface roughness, permeation, closure torque, torque sequencing and re-use on performance of metal C-Ring seals.
Date: October 23, 2007
Creator: Blanton, P & Kurt Eberl, K
Object Type: Article
System: The UNT Digital Library
Results from an International Simulation Study on Coupled Thermal,Hydrological, and Mechanical (THM) Processes near Geological NuclearWaste Repositories (open access)

Results from an International Simulation Study on Coupled Thermal,Hydrological, and Mechanical (THM) Processes near Geological NuclearWaste Repositories

As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.
Date: October 23, 2007
Creator: Rutqvist, Jonny; Rutqvist, J.; Barr, D.; Birkholzer, J.T.; Chijimatsu, M.; Kolditz, O. et al.
Object Type: Article
System: The UNT Digital Library
Subcycle Dynamics in the Laser Ionization of Molecules (open access)

Subcycle Dynamics in the Laser Ionization of Molecules

The time and momentum distributions of electron emission from a molecule during a single laser cycle are calculated by solving a two-dimensional time-dependent Schr{umlt o}dinger equation. The momentum distributions strongly depend on the orbital symmetry and orientation of the molecular axis. Field-induced internal dynamics of the molecule can shift electron emission and recollision times through a large part of the laser cycle, which leads to corresponding variations of high-harmonic emission times and to the appearance of even harmonics.
Date: October 23, 2007
Creator: Xie, X. H.; Wickenhauser, M.; Boutu, W.; Merdji, H.; Salieres, P. & Scrinzi, A.
Object Type: Article
System: The UNT Digital Library
Yucca Mountain Climate Technical Support Representative (open access)

Yucca Mountain Climate Technical Support Representative

The primary objective of Project Activity ORD-FY04-012, “Yucca Mountain Climate Technical Support Representative,” was to provide the Office of Civilian Radioactive Waste Management (OCRWM) with expertise on past, present, and future climate scenarios and to support the technical elements of the Yucca Mountain Project (YMP) climate program. The Climate Technical Support Representative was to explain, defend, and interpret the YMP climate program to the various audiences during Site Recommendation and License Application. This technical support representative was to support DOE management in the preparation and review of documents, and to participate in comment response for the Final Environmental Impact Statement, the Site Recommendation Hearings, the NRC Sufficiency Comments, and other forums as designated by DOE management. Because the activity was terminated 12 months early and experience a 27% reduction in budget, it was not possible to complete all components of the tasks as originally envisioned. Activities not completed include the qualification of climate datasets and the production of a qualified technical report. The following final report is an unqualified summary of the activities that were completed given the reduced time and funding.
Date: October 23, 2007
Creator: Sharpe, Saxon E.
Object Type: Text
System: The UNT Digital Library
Alignment strategy for the ATLAS tracker (open access)

Alignment strategy for the ATLAS tracker

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.
Date: September 23, 2007
Creator: ATLAS & Golling, T.
Object Type: Article
System: The UNT Digital Library
Geologic Descriptions for the Solid-Waste Low Level Burial Grounds (open access)

Geologic Descriptions for the Solid-Waste Low Level Burial Grounds

This document provides the stratigraphic framework and six hydrogeologic cross sections and interpretations for the solid-waste Low Level Burial Grounds on the Hanford Site. Four of the new cross sections are located in the 200 West Area while the other two are located within the 200 East Area. The cross sections display sediments of the vadose zone and uppermost unconfined aquifer.
Date: September 23, 2007
Creator: Bjornstad, Bruce N. & Lanigan, David C.
Object Type: Report
System: The UNT Digital Library
Active Creation of Instrinsically Localized Vibrations in Uranium Using X-Ray and Neutron Scattering (open access)

Active Creation of Instrinsically Localized Vibrations in Uranium Using X-Ray and Neutron Scattering

In real materials, nonlinear forces cause the frequencies of vibrating atoms to depend on amplitude. As a consequence, a large-amplitude fluctuation on the scale of the atom spacing can develop a frequency that does not resonate with the normal modes, causing energy to become trapped in an intrinsically localized mode (ILM)--also called 'discrete breather' or 'lattice soliton'. As temperature is increased, entropy is expected to stabilize increased concentrations of these random hotspots. This mechanism, which spontaneously concentrates energy, has been observed in analogous systems on a larger scale, but direct sightings at the atomic scale have proved difficult. Two challenges have hampered progress: (1) the need to separate ILMs from modes associated with crystal imperfections, and (2) complications that arise at high temperatures, including feature broadening and multiphonon processes. Here we solve both of these problems by actively creating ILMs at low temperatures in {alpha}-uranium using high-energy inelastic x-ray and neutron scattering. The ILM creation excitation occurs at energies ten times higher than conventional lattice excitations, cleanly separating it from modes associated with crystal imperfections. The discovery of this excitation not only proves the existence of ILMs in uranium but also opens up a new route for finding ILMs in …
Date: August 23, 2007
Creator: Manley, M.; Alatas, A.; Trouw, F.; Hults, W.; Leu, B.; Lynn, J. et al.
Object Type: Article
System: The UNT Digital Library
Codes to Model Stars in the Three Dimensions: Virtual Obersvatories (open access)

Codes to Model Stars in the Three Dimensions: Virtual Obersvatories

None
Date: August 23, 2007
Creator: Dearborn, D S
Object Type: Article
System: The UNT Digital Library
An environmental sampling model for combining judgment and randomly placed samples (open access)

An environmental sampling model for combining judgment and randomly placed samples

In the event of the release of a lethal agent (such as anthrax) inside a building, law enforcement and public health responders take samples to identify and characterize the contamination. Sample locations may be rapidly chosen based on available incident details and professional judgment. To achieve greater confidence of whether or not a room or zone was contaminated, or to certify that detectable contamination is not present after decontamination, we consider a Bayesian model for combining the information gained from both judgment and randomly placed samples. We investigate the sensitivity of the model to the parameter inputs and make recommendations for its practical use.
Date: August 23, 2007
Creator: Sego, Landon H.; Anderson, Kevin K.; Matzke, Brett D.; Sieber, Karl; Shulman, Stanley; Bennett, James et al.
Object Type: Report
System: The UNT Digital Library
Final Technical Report, City of Brockton Solar Brightfield: Deploying a Solar Array on a Brockton Brownfield (open access)

Final Technical Report, City of Brockton Solar Brightfield: Deploying a Solar Array on a Brockton Brownfield

The City of Brockton, Massachusetts sought to install New England’s largest solar array at a remediated brownfield site on Grove Street. The 425-kilowatt solar photovoltaic array – or “Brightfield” – was installed in an urban park setting along with interpretive displays to maximize the educational opportunities. The “Brightfield” project included 1,395 310-Watt solar panels connected in “strings” that span the otherwise unusable 3.7-acre site. The project demonstrated that it is both technically and economically feasible to install utility scale solar photovoltaics on a capped landfill site. The US Department of Energy conceived the Brightfields program in 2000, and Brockton’s Brightfield is the largest such installation nationwide. Brockton’s project demonstrated that while it was both technically and economically feasible to perform such a project, the implementation was extremely challenging due to the state policy barriers, difficulty obtaining grant funding, and level of sophistication required to perform the financing and secure required state approvals. This demonstration project can be used as a model for other communities that wish to implement “Brownfields to Brightfields” projects; 2) implementing utility scale solar creates economies of scale that can help to decrease costs of photovoltaics; 3) the project is an aesthetic, environmental, educational and economic asset …
Date: August 23, 2007
Creator: Ribeiro, Lori
Object Type: Report
System: The UNT Digital Library
INVESTIGATION OF THE THERMODYNAMICS GOVERNING METAL HYDRIDE SYNTHESIS IN THE MOLTEN STATE PROCESS. (open access)

INVESTIGATION OF THE THERMODYNAMICS GOVERNING METAL HYDRIDE SYNTHESIS IN THE MOLTEN STATE PROCESS.

Complex metal hydrides have been synthesized for hydrogen storage through a new synthetic technique utilizing high hydrogen overpressure at elevated temperatures (molten state processing). This synthesis technique holds the potential of fusing different complex hydrides at elevated temperatures and pressures to form new species with enhanced hydrogen storage properties. Formation of these compounds is driven by thermodynamic and kinetic considerations. We report on investigations of the thermodynamics. Novel synthetic complexes were formed, structurally characterized, and their hydrogen desorption properties investigated. The effectiveness of the molten state process is compared with mechanicosynthetic ball milling.
Date: August 23, 2007
Creator: Stowe, A; Polly Berseth, P; Ragaiy Zidan, R & Donald Anton, D
Object Type: Article
System: The UNT Digital Library
Quantifying the effects of three-dimensional subsurface heterogeneity on Hortonian runoff processes using a fully-coupled numerical, stochastic approach. (open access)

Quantifying the effects of three-dimensional subsurface heterogeneity on Hortonian runoff processes using a fully-coupled numerical, stochastic approach.

The impact of three-dimensional subsurface heterogeneity on hillslope runoff generated by excess infiltration (so called Hortonian runoff) is examined. A fully-coupled, parallel subsurface overland flow model is used to simulate runoff from an idealized hillslope. Ensembles of correlated, Gaussian random fields of saturated hydraulic conductivity are used to create uncertainty and variability (i.e. structure) due to subsurface heterogeneity. A large number of cases are simulated in a parametric manner with variance of the hydraulic conductivity varied over two orders of magnitude. These cases include rainfall rates above, equal and below the geometric mean of the hydraulic conductivity distribution. These cases are also compared to theoretical considerations of runoff production based on simple assumptions regarding (1) the rainfall rate and the value of hydraulic conductivity in the surface cell using a spatially-indiscriminant approach; and (2) a percolation-theory type approach to incorporate so-called runon. Simulations to test the ergodicity of hydraulic conductivity on hillslope runoff are also performed. Results show three-dimensional features (particularly in the vertical dimension) in the hydraulic conductivity distributions that create shallow perching, which has an important effect on runoff behavior that is fundamentally different in character than previous two dimensional analyses. The simple theories are shown to be …
Date: August 23, 2007
Creator: Maxwell, R M & Kollet, S J
Object Type: Article
System: The UNT Digital Library
SALTSTONE VARIABILITY STUDY - MEASUREMENT OF POROSITY (open access)

SALTSTONE VARIABILITY STUDY - MEASUREMENT OF POROSITY

One of the goals of the Saltstone Variability Study is to identify the operational and compositional variables that control or influence the important processing and performance properties of Saltstone mixes. One of the key performance properties is porosity which is a measure of the volume percent of a cured grout that is occupied by salt solution (for the saturated case). This report presents (1) the results of efforts to develop a method for the measurement of porosity of grout samples and (2) initial results of porosity values for samples that have been previously produced as part of the Saltstone Variability Study. A cost effective measurement method for porosity was developed that provides reproducible results, is relatively fast (30 to 60 minutes per sample) and uses a Mettler Toledo HR83 Moisture Analyzer that is already operational and routinely calibrated at Aiken County Technology Laboratory. The method involves the heating of the sample at 105 C until no further mass loss is observed. This mass loss value, which is due to water evaporation, is then used to calculate the volume percent porosity of the mix. The results of mass loss for mixes at 105 C were equivalent to the results obtained using …
Date: August 23, 2007
Creator: Harbour, J; Vickie Williams, V; Tommy Edwards, T; Russell Eibling, R & Ray Schumacher, R
Object Type: Report
System: The UNT Digital Library
SLUDGE BATCH 4 FOLLOW-UP QUALIFICATION STUDIES TO EVALUATE HYDROGEN GENERATION (open access)

SLUDGE BATCH 4 FOLLOW-UP QUALIFICATION STUDIES TO EVALUATE HYDROGEN GENERATION

Follow-up testing was conducted to better understand the excessive hydrogen generation seen in the initial Sludge Batch 4 (SB4) qualification Sludge Receipt and Adjustment Tank/Slurry Mix Evaporator (SRAT/SME) simulation in the Savannah River National Laboratory (SRNL) Shielded Cells. This effort included both radioactive and simulant work. The initial SB4 qualification test produced 0.59 lbs/hr hydrogen in the SRAT, which was just below the DWPF SRAT limit of 0.65 lbs/hr, and the test produced over 0.5 lbs/hr hydrogen in the SME cycle on two separate occasions, which were over the DWPF SME limit of 0.223 lbs/hr.
Date: August 23, 2007
Creator: Pareizs, J; David Koopman, D; Dan Lambert, D & Cj Bannochie, C
Object Type: Report
System: The UNT Digital Library
Solid-Matrix Luminescence Analysis and Coupling Solid-Matrix Luminescence with Separation Methodology (open access)

Solid-Matrix Luminescence Analysis and Coupling Solid-Matrix Luminescence with Separation Methodology

Research on solid-matrix Luminescence analysis
Date: August 23, 2007
Creator: Hurtubise, Robert J.
Object Type: Report
System: The UNT Digital Library
Application of PILATUS II Detector Modules for High Resolution X-Ray Imaging Crystal Spectrometers on the Alcator C-Mod Tokamak (open access)

Application of PILATUS II Detector Modules for High Resolution X-Ray Imaging Crystal Spectrometers on the Alcator C-Mod Tokamak

A new type of X-ray imaging crystal spectrometer for Doppler measurements of the radial profiles of the ion temperature and plasma rotation velocity in tokamak plasmas is presently being developed in a collaboration between various laboratories. The spectrometer will consist of a spherically bent crystal and a two-dimensional position sensitive detector; and it will record temporally and spatially resolved X-ray line spectra from highly-charged ions. The detector must satisfy challenging requirements with respect to count rate and spatial resolution. The paper presents the results from a recent test of a PILATUS II detector module on Alcator C-Mod, which demonstrate that the PILATUS II detector modules will satisfy these requirements.
Date: July 23, 2007
Creator: M.L. Bitter, Ch. Borennimann, E.F. Eikenberry, K.W. Hill, A. Ince-Chushman, S.G. Lee, J.E. Rice, and S. Scott.
Object Type: Article
System: The UNT Digital Library
Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site (open access)

Characterizing the Catalytic Potential of Deinococcus, Arthrobacter and other Robust Bacteria in Contaminated Subsurface Environments of the Hanford Site

Progress is briefly summarized in these areas: ionizing radiation resistance in bacteria; a hypothesis regarding ionizing radiation resistance emerging for bacterial cells; transcriptome analysis of irradiated D. radiodurans and Shewanella oneidensis; the role of metal reduction in Mn-dependnet Deinococcal species; and engineered Deinococcus strains as models for bioremediation. Key findings are also reported regarding protein oxidation as a possible key to bacterial desiccation resistance, and the whole-genome sequence of the thermophile Deinococcus geothermalis.
Date: July 23, 2007
Creator: Daly, Michael J.
Object Type: Report
System: The UNT Digital Library