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2007 Nuclear Data Review (open access)

2007 Nuclear Data Review

The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composition of the elements are reviewed and recommended values are presented. Half-lives of very long-lived nuclides are presented, including double beta decay, double electron capture, long-lived alpha decay and long-lived beta decay. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. The first observation of the radioactive decay mode of the free neutron is discussed. New measurements that have expanded the neutron drip line for magnesium and aluminum are discussed. Data on recent neutron cross-section and resonance integral measurements are also discussed.
Date: May 5, 2008
Creator: Holden, N. E.
System: The UNT Digital Library
Mesoscale modeling of irreversible volume growth in powders of anisotropic crystals (open access)

Mesoscale modeling of irreversible volume growth in powders of anisotropic crystals

Careful thermometric analysis (TMA) on powders of micron-sized triamino-trinitrobenzene (TATB) crystallites are shown to display irreversible growth in volume when subjected to repeated cycles of heating and cooling. Such behavior is counter-intuitive to typical materials response to simulated annealing cycles in atomic-scale molecular dynamics. However, through coarse-grained simulations using a mesoscale Hamiltonian we quantitatively reproduce irreversible growth behavior in such powdered material. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy, and is mediated by particles much smaller than the average crystallite size.
Date: May 5, 2006
Creator: Gee, R.; Maiti, A. & Fried, L.
System: The UNT Digital Library
Performance of a Buried Radioactive High Level Waste Glass After 24 Years (open access)

Performance of a Buried Radioactive High Level Waste Glass After 24 Years

A radioactive high level waste glass was made in 1980 with Savannah River Site (SRS) Tank 15 waste. This glass was buried in the SRS burial ground for 24 years but lysimeter data was only available for the first 8 years. The glass was exhumed and analyzed in 2004. The glass was predicted to be very durable and laboratory tests confirmed the durability response. The laboratory results indicated that the glass was very durable as did analysis of the lysimeter data. Scanning electron microscopy of the glass burial surface showed no significant glass alteration consistent with the results of the laboratory and field tests. No detectable Pu, Am, Cm, Np, or Ru leached from the glass into the surrounding sediment. Leaching of {beta}/{delta} from {sup 90}Sr and {sup 137}Cs in the glass was diffusion controlled. Less than 0.5% of the Cs and Sr in the glass leached into the surrounding sediment, with >99% of the leached radionuclides remaining within 8 centimeters of the glass pellet.
Date: May 5, 2008
Creator: Jantzen, Carol M.; Kaplan, Daniel J.; Bibler, Ned E.; Peeler, David K. & Plodinec, M. J.
System: The UNT Digital Library
Adjustable Shock Test Sled for Haversine Pulses at 250 fps (open access)

Adjustable Shock Test Sled for Haversine Pulses at 250 fps

New test requirements were developed by Sandia National Laboratory to simulate a regime of shock testing not previously performed at the Kansas City Plant operated by Honeywell Federal Manufacturing & Technologies. These environments were unique in that they involved amplitude of shock >1000g with relatively long pulse durations (greater 5 ms but less than 10 ms) and involved velocity changes up to 235 ft/sec. Ten months were available to develop, design, manufacture and prove-in this new capability. We designed a new shock sled to deliver this new family of shock environments in a laboratory test. The performance range of the new sled includes five specific shocks (1000 g – 8 ms, 1300 - 6 ms, 1500 g – 5.4 ms, 1950 g – 6 ms, 2250 g – 5.4 ms; all haversine shaped), and it also incorporates adjustability to accommodate new shocks within this range. These shock environments result in velocity changes ranging from 160 fps to 250 fps. The test sled accommodates test articles weighing up to 20 lbs and measuring up to 10” along any axis.
Date: May 5, 2008
Creator: Hartwig, Troy; Hower, Brent & Seaholm, Aaron
System: The UNT Digital Library
Further Dosimetry Studies at Rhode Island Nuclear Science Center. (open access)

Further Dosimetry Studies at Rhode Island Nuclear Science Center.

The RINSC is a 2 mega-watt, light water and graphite moderated and cooled reactor that has a graphite thermal column built as a user facility for sample irradiation. Over the past decade, after the reactor conversion from a highly-enriched uranium core to a low-enriched one, flux and dose measurements and calculations had been performed in the thermal column to update the ex-core parameters and to predict the effect from in-core fuel burn-up and rearrangement. The most recent data from measurements and calculations that have been made at the RINSC thermal column since October of 2005 are reported.
Date: May 5, 2008
Creator: Reciniello, R. N.; Holden, N. E.; Hu, J. P.; Johnson, D. G.; Meddleton, M. & Tehan, T. N.
System: The UNT Digital Library
Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows (open access)

Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows

Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer and the Pd catalyst. Addition of 9 percent silver to the palladium catalyst further improved system durability. About 100 full cycles have been demonstrated before devices slow considerably. Degradation of device performance appears to be related to Pd catalyst mobility, rather than delamination or metal layer oxidation issues originally presumed likely to present significant challenges.
Date: May 5, 2008
Creator: Anders, Andre; Slack, Jonathan L. & Richardson, Thomas J.
System: The UNT Digital Library
Characterization of Dosimetry of the BMRR Horizontal Thimble Tubes and Broad Beam Facility. (open access)

Characterization of Dosimetry of the BMRR Horizontal Thimble Tubes and Broad Beam Facility.

The Brookhaven Medical Research Reactor was a 5 mega-watt, light-water cooled and heavy-graphite moderated research facility. It has two shutter-equipped treatment rooms, three horizontally extended thimble tubes, and an ex-core broad beam facility. The three experimental thimbles, or activation ports, external to the reactor tank were designed for several uses, including the investigations on diagnostic and therapeutic methods using radioactive isotopes of very short half-life, the analysis of radiation exposure on tissue-equivalent materials using a collimated neutron beam, and the evaluation of dose effects on biological cells to improve medical treatment. At the broad beam facility where the distribution of thermal neutrons was essential uniform, a wide variety of mammalian whole-body exposures were studied using animals such as burros or mice. Also studied at the broad beam were whole-body phantom experiments, involving the use of a neutron or photon beam streaming through a screen to obtain the flux spectrum suitable for dose analysis on the sugar-urea-water mixture, a tissue-equivalent material. Calculations of the flux and the dose at beam ports based on Monte Carlo particle-transport code were performed, and measurements conducted at the same tally locations were made using bare or cadmium-covered gold foils. Analytical results, which show good agreement …
Date: May 5, 2008
Creator: Hu, J. P.; Reciniello, R. N. & Holden, N. E.
System: The UNT Digital Library
3D-Simulation Studies of SNS Ring Doublet Magnets (open access)

3D-Simulation Studies of SNS Ring Doublet Magnets

The accumulator ring of the Spallation Neutron Source (SNS) at ORNL employs in its straight sections closely packed quadrupole doublemagnets with large aperture of R=15.1 cm an relatively short iron-to-iron distance of 51.4 cm. These quads have much extended fringe field, and magnetic interferences among them in the doublet assemblies is not avoidable. Though each magnet in the assemblies has been individually mapped to high accuracy of lower than 0.01 percent level, the experimental data including the magnetic interference effect will not be available. We have performed 3D computing simulations on a quadrupole doublet model in order to assess the degree of the interference and to obtain relevant data for the SNS commissioning and operation.
Date: May 5, 2005
Creator: Wang, J. G.; N., Tsoupas & Venturini, M.
System: The UNT Digital Library
Suppression of Large Edge Localized Modes with Edge Resonant Magnetic Fields in High Confinement DIII-D Plasmas (open access)

Suppression of Large Edge Localized Modes with Edge Resonant Magnetic Fields in High Confinement DIII-D Plasmas

None
Date: May 5, 2005
Creator: Evans, T. E.; Moyer, R. A.; Watkins, J. G.; Osborne, T. H.; Thomas, P. R.; Becoulet, M. et al.
System: The UNT Digital Library
Demonstration of Successful X-ray Thomson Scattering Using Picosecond K-(alpha) X-ray Sources for the Characterization of Dense Heated Matter (open access)

Demonstration of Successful X-ray Thomson Scattering Using Picosecond K-(alpha) X-ray Sources for the Characterization of Dense Heated Matter

We discuss the first successful K-{alpha} x-ray Thomson scattering experiment from solid density plasmas for use as a diagnostic in determining the temperature, density, and ionization state of warm dense matter with picosecond resolution. The development of this source as a diagnostic and stringent requirements for successful K-{alpha} x-ray Thomson scattering are addressed. Data for the experimental techniques described in this paper [1] suggest the capability of single shot characterization of warm dense matter and the ability to use this scattering source at future Free Electron Lasers (FEL) where comparable scattering signal levels are predicted.
Date: May 5, 2008
Creator: Kritcher, A.; Neumayer, P.; Lee, H. J.; Doeppner, T.; Falcone, R.; Glenzer, S. et al.
System: The UNT Digital Library
RECENT BEAM MEASUREMENTS AND NEW INSTRUMENTATION AT THE ADVANCED LIGHT SOURCE (open access)

RECENT BEAM MEASUREMENTS AND NEW INSTRUMENTATION AT THE ADVANCED LIGHT SOURCE

The Advanced Light Source (ALS) in Berkeley was the first of the soft x-ray third generation light source ever built, and since 1993 has been in continuous and successful operation serving a large community of users in the VUV and soft x-ray community. During these years the storage ring underwent through several important upgrades that allowed maintaining the performance of this veteran facility at the forefront. The ALS beam diagnostics and instrumentation have followed a similar path of innovation and upgrade and nowadays include most of the modem and last generation devices and technologies that are commercially available and used in the recently constructed third generation light sources. In this paper we will not focus on such already widely known systems, but we will concentrate our effort in the description of some measurements techniques, instrumentation and diagnostic systems specifically developed at the ALS and used during the last few years.
Date: May 5, 2008
Creator: Sannibale, Fernando; Baptiste, Kenneth; Barry, Walter; Chin, Michael; Filippetto, Daniele; Jaegerhofer, Lukas et al.
System: The UNT Digital Library
Supersymmetry and Superstring Phenomenology (open access)

Supersymmetry and Superstring Phenomenology

We briefly cover the early history of supersymmetry, describe the relation of SUSY quantum field theories to superstring theories and explain why they are considered a likely tool to describe the phenomenology of high energy particle theory beyond the Standard Model.
Date: May 5, 2008
Creator: Gaillard, Mary K; Gaillard, Mary K. & Zumino, Bruno
System: The UNT Digital Library
Magnet options for sensors for the pulp and paper industry (open access)

Magnet options for sensors for the pulp and paper industry

The Lawrence Berkeley National Laboratory (LBNL) has been developing sensors for the pulp and paper industry that uses a magnetic field. The applications for magnetic sensors that have studied include (1) sensors for the measurement of the water and ice content of wood chips entering the pulping mill, (2) sensors for measuring the water content and other constituents of the black liquor leaving the paper digester, and (3) sensors for measuring paper thickness and water content as the paper is being processed. These tasks can be done using nuclear magnetic resonance (NMR). The magnetic field used for doing the NMR can come from either permanent magnets or superconducting magnets. The choice of the magnet is dependent on a number of factors, which include the size of the sample and field strength needed to do the sensing task at hand. This paper describes some superconducting magnet options that can be used in the pulp and paper industry.
Date: May 5, 2001
Creator: Green, M. A.; Barale, P. J.; Fong, C. G.; Luft, P. A.; Reimer, J. A. & Yahnke, M. S.
System: The UNT Digital Library
Reanalysis of the Schwertmannite structure and the incorporationof SO42- groups: An IR, XAS, WAXS and simulation study (open access)

Reanalysis of the Schwertmannite structure and the incorporationof SO42- groups: An IR, XAS, WAXS and simulation study

Schwertmannite is a poorly crystallized iron oxyhydroxidewith essential structural sulfate that can be a major component in acidmine drainage environments. Original characterization work concluded thatthe sulfate was largely contained within tunnels of an orderedakaganeite-like structure based on powder XRD, analysis of IR spectra,and sulfate extraction procedures [1]. Since the original description,problems have emerged with the nature of the tunnel sulfate, and with theinterpretation of the IR spectra. Other related work has shown that it isnow possible to determine sulfate-iron oxide inner sphere bindingunambiguously from the S K-edge XANES spectrum. Hence a reassessment ofthe evidence for the original schwertmannite structure was deemednecessary and timely.
Date: May 5, 2001
Creator: Waychunas, G.A.; Myneni, S.C.B.; Traina, S.J.; Bigham, J.M.; Fuller, C.C. & Davis, J.A.
System: The UNT Digital Library
Development and Characterization of a High Magnetic Field Solenoid for Laser Plasma Experiments (open access)

Development and Characterization of a High Magnetic Field Solenoid for Laser Plasma Experiments

An electromagnetic solenoid was developed to study the quenching of nonlocal heat transport in laser-produced gas-jet plasmas by high external magnetic fields. The solenoid, which is driven by a pulsed power system supplying 30 kJ, achieves fields exceeding 10 T. Temporally resolved measurements of the electron temperature profile transverse to a high power laser beam were obtained using Thomson Scattering. A method for optimizing the solenoid design based on the available stored energy is presented.
Date: May 5, 2006
Creator: Pollock, B B; Froula, D H; Davis, P F; Ross, J S; Divol, L; Fulkerson, S et al.
System: The UNT Digital Library
Supersymmetry Parameter Analysis: SPA Convention and Project (open access)

Supersymmetry Parameter Analysis: SPA Convention and Project

High-precision analyses of supersymmetry parameters aim atreconstructing the fundamental supersymmetric theory and its breakingmechanism. A well defined theoretical framework is needed whenhigher-order corrections are included. We propose such a scheme,Supersymmetry Parameter Analysis SPA, based on a consistent set ofconventions and input parameters. A repository for computer programs isprovided which connect parameters in different schemes and relate theLagrangian parameters to physical observables at LHC and high energy e+e-linear collider experiments, i.e., masses, mixings, decay widths andproduction cross sections for supersymmetric particles. In addition,programs for calculating high-precision low energy observables, thedensity of cold dark matter (CDM) in the universe as well as the crosssections for CDM search experiments are included. The SPA scheme stillrequires extended efforts on both the theoretical and experimental sidebefore data can be evaluated in the future at the level of the desiredprecision. We take here an initial step of testing the SPA scheme byapplying the techniques involved to a specific supersymmetry referencepoint.
Date: May 5, 2005
Creator: Hinchliffe, I. & al., et
System: The UNT Digital Library
Introduction to First-Principles Electronic Structure Methods: Application to Actinide Materials (open access)

Introduction to First-Principles Electronic Structure Methods: Application to Actinide Materials

This paper provides an introduction for non-experts to first-principles electronic structure methods that are widely used in condensed-matter physics. Particular emphasis is placed on giving the appropriate background information needed to better appreciate the use of these methods to study actinide and other materials. Specifically, I describe the underlying theory sufficiently to enable an understanding of the relative strengths and weaknesses of the methods. I also explain the meaning of commonly used terminology, including density functional theory (DFT), local density approximation (LDA), and generalized gradient approximation (GGA), as well as linear muffin-tin orbital (LMTO), linear augmented plane wave (LAPW), and pseudopotential methods. I also briefly discuss methodologies that extend the basic theory to address specific limitations. Finally, I describe a few illustrative applications, including quantum molecular dynamics (QMD) simulations and studies of surfaces, impurities, and defects. I conclude by addressing the current controversy regarding magnetic calculations for actinide materials.
Date: May 5, 2006
Creator: Klepeis, J E
System: The UNT Digital Library
Signals from the Noise: Image Stacking for Quasars in the FIRST Survey (open access)

Signals from the Noise: Image Stacking for Quasars in the FIRST Survey

We present a technique to explore the radio sky into the nanoJansky regime by employing image stacking using the FIRST radio sky survey. We begin with a discussion of the non-intuitive relationship between the mean and median values of a non-Gaussian distribution in which measurements of the members of the distribution are dominated by noise. Following a detailed examination of the systematic effects present in the 20 cm VLA snapshot images that comprise FIRST, we demonstrate that image stacking allows us to recover the average properties of source populations with flux densities a factor of 30 or more below the rms noise level. With the calibration described herein, mean estimates of radio flux density, luminosity, radio loudness, etc. are derivable for any undetected source class having arcsecond positional accuracy. We demonstrate the utility of this technique by exploring the radio properties of quasars found in the Sloan Digital Sky Survey. We compute the mean luminosities and radio-loudness parameters for 41,295 quasars in the SDSS DR3 catalog. There is a tight correlation between optical and radio luminosity, with the radio luminosity increasing as the 0.72 power of optical luminosity. This implies declining radio-loudness with optical luminosity, with the most luminous objects …
Date: May 5, 2006
Creator: White, R L; Helfand, D J; Becker, R H; Glikman, E & deVries, W
System: The UNT Digital Library
Timing Calibration in PET Using a Time Alignment Probe (open access)

Timing Calibration in PET Using a Time Alignment Probe

We evaluate the Scanwell Time Alignment Probe for performing the timing calibration for the LBNL Prostate-Specific PET Camera. We calibrate the time delay correction factors for each detector module in the camera using two methods--using the Time Alignment Probe (which measures the time difference between the probe and each detector module) and using the conventional method (which measures the timing difference between all module-module combinations in the camera). These correction factors, which are quantized in 2 ns steps, are compared on a module-by-module basis. The values are in excellent agreement--of the 80 correction factors, 62 agree exactly, 17 differ by 1 step, and 1 differs by 2 steps. We also measure on-time and off-time counting rates when the two sets of calibration factors are loaded into the camera and find that they agree within statistical error. We conclude that the performance using the Time Alignment Probe and conventional methods are equivalent.
Date: May 5, 2006
Creator: Moses, William W. & Thompson, Christopher J.
System: The UNT Digital Library
Expansion of radiative cooling of the laser induced plasma (open access)

Expansion of radiative cooling of the laser induced plasma

To study the expansion and cooling process of the laser induced plasma generated by nanosecond pulsed laser ablation, experiments have been conducted which measure the position of the external shockwaves and the temperature of the vapor plumes. The positions of external shockwaves were determined by a femtosecond laser time-resolved imaging system. Vapor plume temperature was determined from spectroscopic measurements of the plasma emission lines. A model which considers the mass, momentum, and energy conservation of the region affected by the laser energy was developed. It shows good agreement to the experimental data.
Date: May 5, 2006
Creator: Wen, Sy-Bor; Mao, Xianglei; Liu, Chunyi; Greif, Ralph & Russo,Richard
System: The UNT Digital Library
Multi-CFD Timing Estimators for PET Block Detectors (open access)

Multi-CFD Timing Estimators for PET Block Detectors

In a conventional PET system with block detectors, a timing estimator is created by generating the analog sum of the signals from the four photomultiplier tubes (PMT) in a module and discriminating the sum with a single constant fraction discriminator (CFD). The differences in the propagation time between the PMTs in the module can potentially degrade the timing resolution of the module. While this degradation is probably too small to affect performance in conventional PET imaging, it may impact the timing inaccuracy for time-of-flight PET systems (which have higher timing resolution requirements). Using a separate CFD for each PMT would allow for propagation time differences to be removed through calibration and correction in software. In this paper we investigate and quantify the timing resolution achievable when the signal from each of the 4 PMTs is digitized by a separate CFD. Several methods are explored for both obtaining values for the propagation time differences between the PMTs and combining the four arrival times to form a single timing estimator. We find that the propagation time correction factors are best derived through an exhaustive search, and that the ''weighted average'' method provides the best timing estimator. Using these methods, the timing resolution …
Date: May 5, 2006
Creator: Ullisch, Marcus G. & Moses, William W.
System: The UNT Digital Library
Experimental Signatures of Homoclinic Tangles in Poloidally Diverted Tokamaks (open access)

Experimental Signatures of Homoclinic Tangles in Poloidally Diverted Tokamaks

None
Date: May 5, 2005
Creator: Evans, T E; Roeder, R W; Carter, J A; Rapoport, B I; Fenstermacher, M E & Lasnier, C J
System: The UNT Digital Library
Variability of Ocean Heat Uptake: Reconciling Observations and Models (open access)

Variability of Ocean Heat Uptake: Reconciling Observations and Models

This study examines the temporal variability of ocean heat uptake in observations and in climate models. Previous work suggests that coupled Atmosphere-Ocean General Circulation Models (A-OGCMs) may have underestimated the observed natural variability of ocean heat content, particularly on decadal and longer timescales. To address this issue, we rely on observed estimates of heat content from the 2004 World Ocean Atlas (WOA-2004) compiled by Levitus et al. (2005). Given information about the distribution of observations in WOA-2004, we evaluate the effects of sparse observational coverage and the infilling that Levitus et al. use to produce the spatially-complete temperature fields required to compute heat content variations. We first show that in ocean basins with limited observational coverage, there are important differences between ocean temperature variability estimated from observed and infilled portions of the basin. We then employ data from control simulations performed with eight different A-OGCMs as a test-bed for studying the effects of sparse, space- and time-varying observational coverage. Subsampling model data with actual observational coverage has a large impact on the inferred temperature variability in the top 300 and 3000 meters of the ocean. This arises from changes in both sampling depth and in the geographical areas sampled. Our …
Date: May 5, 2005
Creator: AchutaRao, K. M.; Santer, B. D.; Gleckler, P. J.; Taylor, K.; Pierce, D.; Barnett, T. et al.
System: The UNT Digital Library
An Integrated Hydrologic Bayesian Multi-Model Combination Framework: Confronting Input, parameter and model structural uncertainty in Hydrologic Prediction (open access)

An Integrated Hydrologic Bayesian Multi-Model Combination Framework: Confronting Input, parameter and model structural uncertainty in Hydrologic Prediction

This paper presents a new technique--Integrated Bayesian Uncertainty Estimator (IBUNE) to account for the major uncertainties of hydrologic rainfall-runoff predictions explicitly. The uncertainties from the input (forcing) data--mainly the precipitation observations and from the model parameters are reduced through a Monte Carlo Markov Chain (MCMC) scheme named Shuffled Complex Evolution Metropolis (SCEM) algorithm which has been extended to include a precipitation error model. Afterwards, the Bayesian Model Averaging (BMA) scheme is employed to further improve the prediction skill and uncertainty estimation using multiple model output. A series of case studies using three rainfall-runoff models to predict the streamflow in the Leaf River basin, Mississippi are used to examine the necessity and usefulness of this technique. The results suggests that ignoring either input forcings error or model structural uncertainty will lead to unrealistic model simulations and their associated uncertainty bounds which does not consistently capture and represent the real-world behavior of the watershed.
Date: May 5, 2006
Creator: Ajami, N. K.; Duan, Q. & Sorooshian, S.
System: The UNT Digital Library