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TRANSPARENCY: Tracking Uranium under the U.S. / Russian HEU Purchase Agreement (open access)

TRANSPARENCY: Tracking Uranium under the U.S. / Russian HEU Purchase Agreement

By the end of August, 2005, the Russia Federation delivered to the United States (U.S.) more than 7,000 metric tons (MT) of low enriched uranium (LEU) containing approximately 46 million SWU and 75,000 MT of natural uranium. This uranium was blended down from weapons-grade (nominally enriched to 90% {sup 235}U) highly enriched uranium (HEU) under the 1993 HEU Purchase Agreement that provides for the blend down of 500 MT HEU into LEU for use as fuel in commercial nuclear reactors. The HEU Transparency Program, under the National Nuclear Security Administration (NNSA), monitored the conversion and blending of the more than 250 MT HEU used to produce this LEU. The HEU represents more than half of the 500 MT HEU scheduled to be blended down through the year 2013 and is equivalent to the elimination of more than 10,000 nuclear devices. The HEU Transparency Program has made considerable progress in its mission to develop and implement transparency measures necessary to assure that Russian HEU extracted from dismantled Russian nuclear weapons is blended down into LEU for delivery to the United States. U.S. monitor observations include the inventory of in process containers, observation of plant operations, nondestructive assay measurements to determine {sup …
Date: October 19, 2005
Creator: Benton, J B; Decman, D J & Leich, D A
System: The UNT Digital Library
Miniatuization of the flowing fluid electric conductivity loggingtec hnique (open access)

Miniatuization of the flowing fluid electric conductivity loggingtec hnique

An understanding of both the hydraulic properties of the aquifer and the depth distribution of salts is critical for evaluating the potential of groundwater for conjunctive water use and for maintaining suitable groundwater quality in agricultural regions where groundwater is used extensively for irrigation and drinking water. The electrical conductivity profiles recorded in a well using the flowing fluid electric conductivity logging (FEC logging) method can be analyzed to estimate interval specific hydraulic conductivity and estimates of the salinity concentration with depth. However, irrigation wells that are common in agricultural regions have limited access into them because these wells are still in operation, and the traditional equipment used for FEC logging cannot fit through the small access pipe intersecting the well. A modified, miniaturized FEC logging technique was developed such that this logging method could be used in wells with limited access. In addition, a new method for injecting water over the entire screened interval of the well was developed to reduce the time required to perform FEC logging. Results of FEC logging using the new methodology and miniaturized system in two irrigation wells are also summarized.
Date: October 19, 2005
Creator: Su, Grace W.; Quinn, Nigel W.T.; Cook, Paul J. & Shipp, William
System: The UNT Digital Library
Density Changes in Plutonium Observed from Accelerated Aging Using Pu-238 Enrichment (open access)

Density Changes in Plutonium Observed from Accelerated Aging Using Pu-238 Enrichment

In support of Stockpile Stewardship activities, accelerated aging tests on a plutonium alloy enriched with 7.3 atomic percentage of {sup 238}Pu is underway using dilatometry at 35, 50, and 65 C and immersion density measurements of material stored at 50 C. Changes in density are expected from radiation damage in the lattice and helium in-growth. After twenty-five equivalent years of aging, the dilatometry data shows that the alloys at 35 C have expanded in volume by 0.11% to 0.12% and have started to exhibit a near linear expansion behavior primarily caused by the helium accumulation. The average He-to-vacancy ratio from tested specimens was determined to be around 2.3. The model for the lattice damage and helium in-growth accurately represents the volume swelling at 35 C. The density converted from the dilatometry corresponds well to the decreasing density trend of reference plutonium alloys as a function of time.
Date: October 19, 2005
Creator: Chung, B. W.; Thompson, S. R.; Woods, C. H.; Hopkins, D. J.; Gourdin, W. H. & Ebbinghaus, B. B.
System: The UNT Digital Library
Geomechanical/Geochemical Modeling Studies Conducted within theInternational DECOVALEX Project (open access)

Geomechanical/Geochemical Modeling Studies Conducted within theInternational DECOVALEX Project

The DECOVALEX project is an international cooperative project initiated by SKI, the Swedish Nuclear Power Inspectorate, with participation of about 10 international organizations. The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled thermo-hydro-mechanical-chemical (THMC) processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. One of the research tasks, initiated in 2004 by the U.S. Department of Energy (DOE), addresses the long-term impact of geomechanical and geochemical processes on the flow conditions near waste emplacement tunnels. Within this task, four international research teams conduct predictive analysis of the coupled processes in two generic repositories, using multiple approaches and different computer codes. Below, we give an overview of the research task and report its current status.
Date: October 19, 2005
Creator: Birkholzer, J.T.; Rutqvist, J.; Sonnenthal, E.L.; Barr, D.; Chijimatsu, M.; Kolditz, O. et al.
System: The UNT Digital Library
PSTD Simulations of Multiple Light Scattering in 3-D Macrocsopic Random Media (open access)

PSTD Simulations of Multiple Light Scattering in 3-D Macrocsopic Random Media

We report a full-vector, three-dimensional, numerical solution of Maxwell's equations for optical propagation within, and scattering by, a random medium of macroscopic dimensions. The total scattering cross-section is determined using the pseudospectral time-domain technique. Specific results reported in this Paper indicate that multiply scattered light also contains information that can be extracted by the proposed cross-correlation analysis. On a broader perspective, our results demonstrate the feasibility of accurately determining the optical characteristics of arbitrary, macroscopic random media, including geometries with continuous variations of refractive index. Specifically, our results point toward the new possibilities of tissue optics--by numerically solving Maxwell's equations, the optical properties of tissue structures can be determined unambiguously.
Date: October 19, 2005
Creator: Tseng, S H; Taflove, A; Maitland, D & Backman, V
System: The UNT Digital Library
Compton Scattering X-Ray Sources Driven by Laser Wakefield Acceleration (open access)

Compton Scattering X-Ray Sources Driven by Laser Wakefield Acceleration

Recent laser wakefield acceleration experiments have demonstrated the generation of femtosecond, nano-Coulomb, low emittance, nearly monokinetic relativistic electron bunches of sufficient quality to produce bright, tunable, ultrafast x-rays via Compton scattering. Design parameters for a proof-of-concept experiment are presented using a three-dimensional Compton scattering code and a laser-plasma interaction particle-in-cell code modeling the wakefield acceleration process; x-ray fluxes exceeding 10{sup 22} s{sup -1} are predicted, with a peak brightness > 10{sup 20} photons/(mm{sup 2} x mrad{sup 2} x s x 0.1% bandwidth).
Date: October 19, 2005
Creator: Hartemann, F V; Gibson, D J; Brown, W J; Rousse, A; Phuoc, K T & Pukhov, A
System: The UNT Digital Library
Search for Pentaquarks at BABAR (open access)

Search for Pentaquarks at BABAR

The results of searches for the strange pentaquark states, {Theta}{sub 5}(1540){sup +}, {Xi}{sub 5}(1860){sup --} and {Xi}{sub 5}(1860){sup 0} in data recorded by the BABAR experiment are presented. We search for these three states inclusively in 123.4 fb{sup -1} of e{sup +}e{sup -} annihilation data produced at the PEP-II asymmetric storage rings; we find no evidence for their production in any physics process, and set limits on their production rates that are well below the measured rates for conventional baryons. We also search for {Theta}{sub 5}(1540){sup +} produced in interactions of electrons or hadrons in the material of the inner part of the detector. No evidence for this state is found in a sample with much higher statistics than similar electroproduction experiments that claim a signal.
Date: October 19, 2005
Creator: Gotzen, K. & /Ruhr U., Bochum
System: The UNT Digital Library
Adaptive Perturbation Theory: Quantum Mechanics and Field Theory (open access)

Adaptive Perturbation Theory: Quantum Mechanics and Field Theory

Adaptive perturbation is a new method for perturbatively computing the eigenvalues and eigenstates of quantum mechanical Hamiltonians that are widely believed not to be solvable by such methods. The novel feature of adaptive perturbation theory is that it decomposes a given Hamiltonian, H, into an unperturbed part and a perturbation in a way which extracts the leading non-perturbative behavior of the problem exactly. In this talk I will introduce the method in the context of the pure anharmonic oscillator and then apply it to the case of tunneling between symmetric minima. After that, I will show how this method can be applied to field theory. In that discussion I will show how one can non-perturbatively extract the structure of mass, wavefunction and coupling constant renormalization.
Date: October 19, 2005
Creator: Weinstein, Marvin
System: The UNT Digital Library
Charmless Quasi-Two-Body Modes at BaBar (open access)

Charmless Quasi-Two-Body Modes at BaBar

We present results for measurements of B{sup 0} meson decays to charmless final states {eta}K{sup 0}, {eta}{omega}, a{sub 1}{sup +}(1260){pi}{sup -} with a{sub 1}{sup +}(1260) {yields} {pi}{sup +}{pi}{sup +}{pi}{sup -}, {rho}{sup 0}K{sub S}{sup 0}, K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}, and of B{sup +} to {eta}{rho}{sup +} and {eta}{prime}{pi}{sup +}. Analyses are based on data taken with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC.
Date: October 19, 2005
Creator: Palombo, F. & /INFN, Milan
System: The UNT Digital Library
Influence of Specimen Size on the SCC Growth Rate of Ni-Alloys Exposed to High Temperature Water (open access)

Influence of Specimen Size on the SCC Growth Rate of Ni-Alloys Exposed to High Temperature Water

Tests were conducted on a single heat of Alloy 600 using compact tension specimens ranging from 50.80 mm (2 inches) in gross thickness (2T) to 10.16 mm (0.4 inches, 0.4T) in gross thickness. Results indicated that at stress intensity factor (K) levels above 55 MPa{radical}m, the growth rate is affected by specimen size in deaerated primary water. The growth rate can be significantly faster in 0.4T and 0.6T (15.24 mm = 0.6 inches in gross thickness) specimens at these elevated K levels compared to 2T specimens. Stress corrosion crack (SCC) growth rates > 6 x 10{sup -7} mm/s were observed at 338 C and 40 cc/kg H{sub 2} in 0.6T and 0.4T specimens at these elevated K levels, although the fracture mode was not significantly affected by the specimen size. The SCC growth rate of 2T specimens under comparable test conditions was {approx}6 x 10{sup -8} mm/s. All of the specimens examined that were tested at K > 55 MPa{radical}m exhibited intergranular failure, although ductile dimples and cracked grains were observed in the 0.4T specimens loaded to the elevated K levels. The effect of specimen size on the crack growth behavior indicated by electric potential drop (EPD) monitoring at K …
Date: October 19, 2005
Creator: Richey, E; Morton, D & Moshier, W
System: The UNT Digital Library
The Effect of Load-Line Displacement Rate on the SCC Growth Rate of Nickel Alloys and Mechanistic Implications (open access)

The Effect of Load-Line Displacement Rate on the SCC Growth Rate of Nickel Alloys and Mechanistic Implications

A key set of SCC growth experiments was designed to test the hypothesis that deformation/creep is the rate controlling step in LPSCC. These tests were performed on Alloy X-750 AH compact tension specimens at a various constant displacement rates. The deformation/creep rate within the crack tip zone is proportional to the test displacement rate. If crack growth rates were observed to increase with the load-line displacement rate, then this would indicate that deformation/creep is a critical SCC mechanism process. However, results obtained from the load-line displacement tests did not find X-750 AH SCC growth rate to be dependent on the position rate and therefore do not support the assumption that deformation/creep is the rate controlling process in LPSCC. The similarities between the SCC response of X-750, Alloy 600 and EN82H suggests that it is likely that the same SCC process is occurring for all these alloys (i.e., the same rate controlling step) and that deformation based models are also inappropriate for Alloy 600 and EN82H. The strong temperature and coolant hydrogen dependencies exhibited by these alloys make it more likely that nickel alloy LPSCC is controlled by an environmental or corrosion driven process.
Date: October 19, 2005
Creator: Morton, D
System: The UNT Digital Library
Searches for Pentaquark Baryons at BaBar (open access)

Searches for Pentaquark Baryons at BaBar

This paper presents the results of inclusive searches for the strange pentaquark states {Theta}{sup +}(1540), {Xi}{sub 5}{sup --}(1860) and {Xi}{sub 5}(1860){sup 0} as well as the anti-charm pentaquark state {Theta}{sub c}(3099){sup 0} in a dataset of 123.4 fb{sup -1} collected on and 40MeV below the {Upsilon}(4S) resonance by the BABAR detector at the e{sup +}e{sup -} PEP-II storage rings. No evidence for the pentaquark states is found and upper limits on the rate of {Theta}{sup +}(1540) and {Xi}{sub 5}{sup --}(1860) production in e{sup +}e{sup -} annihilation are obtained.
Date: October 19, 2005
Creator: Berger-Hryn'ova, Tetiana
System: The UNT Digital Library
Studies of $e^+e^-$ Collisions with a Hard Initial-State Photon at BaBar (open access)

Studies of $e^+e^-$ Collisions with a Hard Initial-State Photon at BaBar

The authors present preliminary BaBar measurements of hadronic cross sections in e{sup +}e{sup -} annihilation using the radiative return technique. The cross sections for e{sup +}e{sup -} {yields} p{bar p}, 3({pi}{sup +}{pi}{sup -}), 2({pi}{sup +}{pi}{sup -})2{pi}{sup 0}, and K{sup +}K{sup -}2({pi}{sup +}{pi}{sup -}) are measured. Measurements of the proton form factor and of the ratio G{sub E}/G{sub M} are also shown.
Date: October 19, 2005
Creator: Berger, Nicolas
System: The UNT Digital Library
The Effect of Ionizing Radiation U6+ Phases (open access)

The Effect of Ionizing Radiation U6+ Phases

None
Date: October 19, 2005
Creator: Utsunomiya, S. & Ewing, R. C.
System: The UNT Digital Library