RADIOISOTOPES AND RADIATION APPLICATIONS. Quarterly Progress Report No. 12 (open access)

RADIOISOTOPES AND RADIATION APPLICATIONS. Quarterly Progress Report No. 12

Continued research is reported in the areas of intrinsic radioactive tracers for industrial process control and the effects of structural factors on radioinduced graft polymerization. The use of Be-- Po neutron sources for production of short-lived isotopes is being investigated. Data are included on the effects of target volume, high-Z scattering media, target-isotope concentration, and macroscopic cross-section on speciflc and total activation produced with a 10-curie source. Research on graft-polyerization concerning the effects of structure on freetinued. Results indicate that the radical formed in a variety of substituted methacrylate polymers is the same in all cases. (J.R.D.)
Date: April 18, 1962
Creator: Sunderman, D.N. ed.
Object Type: Report
System: The UNT Digital Library
Workshop on photon activation therapy: proceedings (open access)

Workshop on photon activation therapy: proceedings

This Workshop was held concurrently with an IAEA Research Coordination Meeting on Exploration of the Possibility of High-LET Radiation for Non-conventional Radiotherapy in Cancer. The Workshop on Photon Activation Therapy (PAT) was given as a special session on April 18, as it was thoght PAT might eventually be found to be attractive to developing countries, which is a major concern of the IAEA. An effort was made to bring together representatives of the various groups known to be actively working on PAT; these included investigators from Sweden and Japan as well as the US. It is hoped that this compendium of papers will be of use to those currently active in this developing field, as well as to those who might join this area of endeavor in the future.
Date: April 18, 1985
Creator: Fairchild, R.G. (ed.)
Object Type: Article
System: The UNT Digital Library
Silver isotopic anomalies in iron meteorites: cosmic-ray production and other possible sources (open access)

Silver isotopic anomalies in iron meteorites: cosmic-ray production and other possible sources

The sources of excess /sup 107/Ag observed in iron meteorites by Kaiser, Kelly, and Wasserburg (1980) are examined, with emphasis on the reactions of cosmic-ray particles with palladium. The cross sections for the production of the silver isotopes from palladium by energetic cosmic-ray particles are evaluated or estimated and used to calculate spallogenic production rates relative to that of /sup 53/Mn from iron. The upper limit for the production rate of excess /sup 107/Ag by galactic-cosmic-ray particles is 400 atoms/min/kg(Pd) which, over an exposure age of 10/sup 9/ years, would make only 1% of the observed excesses of /sup 107/Ag. Neutron-capture reactions with Pd isotopes produce mainly /sup 109/Ag. Binary fission of a siderophilic superheavy element would be expected to yield more /sup 109/Ag than /sup 107/Ag. An intense proton irradiation in the early solar system probably would produce a lower ratio of (/sup 107/Pd//sup 108/Pd) to (/sup 26/Al//sup 27/Al) than observed in meteorites. Therefore the presence of excess /sup 107/Ag in iron meteorites with large Pd/Ag ratios very likely is due to the incorporation of 6.5 x 10/sup 6/-year /sup 107/Pd of nucleosynthetic origin in these meteorites.
Date: April 18, 1980
Creator: Reedy, R. C.
Object Type: Article
System: The UNT Digital Library
Advanced gas cooled nuclear reactor materials evaluation and development program. Progress report, October 1, 1979-December 31, 1979 (open access)

Advanced gas cooled nuclear reactor materials evaluation and development program. Progress report, October 1, 1979-December 31, 1979

This report presents the results of work performed from October 1, 1979 through December 31, 1979. Work covered in this report includes the activities associated with the status of the simulated reactor helium supply system, testing equipment and gas chemistry analysis instrumentation and equipment. The progress in the screening test program is described. This includes: screening creep results, weight gain and post-exposure mechanical properties for materials thermally exposed at 750/sup 0/ and 850/sup 0/C (1382/sup 0/ and 1562/sup 0/F). In addition, the status of the data management system is described.
Date: April 18, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Summary of S = 0 dibaryon resonances and candidates (open access)

Summary of S = 0 dibaryon resonances and candidates

Experimental data concerning S = O dibaryon resonances are reviewed, with an emphasis on the nucleon-nucelon system. Structures observed in the ..gamma..d channel, the ..pi..d elastic scattering, pp ..-->.. ..pi..d channel, and other channels are discussed. Experimental data are compared with various theories. The short-range forces can be represented by dibaryon resonances. Further measurements to clarify the understanding of dibaryons are also discussed. 53 refs., 24 figs.
Date: April 18, 1985
Creator: Yokosawa, A.
Object Type: Article
System: The UNT Digital Library
Energy savings by means of fuel cell electrodes in electro-chemical industries. Progress report, November 1, 1979-January 31, 1980 (open access)

Energy savings by means of fuel cell electrodes in electro-chemical industries. Progress report, November 1, 1979-January 31, 1980

Zinc electrowinning data, obtained with hydrogen depolarized anodes operating in a plant feed electrolyte at 55/sup 0/C, are presented in this quarterly report for investigations involving the following: performance of an anode containing a low platinum loading, i.e. 0.09 mg/cm/sup 2/ instead of the typical 0.33 mg/cm/sup 2/, and an anode catalyzed with palladium instead of platinum; establishment of a feed and bleed system to maintain a constant electrolyte composition; exploratory experiments on the effect of the rate and mode of electrolyte flow on the quality of the zinc plate at high current densities; performance of the anode with feeds of varying degrees of purification pre-treatment, and containing either 50 or 150 g/l Zn/sup + +/; the effect upon cell voltage of decreasing the hydrogen flowrate to the anode by dilution of the feed gas with nitrogen; the effect upon cell voltage of increasing the back pressure of the hydrogen gas fed to the anode; the effect upon energy consumption and current efficiency of varying the current density and the Zn/sup + +/ concentration; trace elemental analysis of a cathodic zinc plate of commercial-size thickness, as produced using the catalytic H/sub 2/ anode; further comparison of the effects of feed …
Date: April 18, 1980
Creator: Bar-Ilan, A.; Juda, W.; Allen, R.J. & Lindstrom, R.W.
Object Type: Report
System: The UNT Digital Library
Calculation of Departure From Nucleate Boiling Conditions for the Spert Iii Reactor in the High Pressure Region (open access)

Calculation of Departure From Nucleate Boiling Conditions for the Spert Iii Reactor in the High Pressure Region

Calculations are made to determine the safe steadystate power operating limits of the Spert III reactor from the viewpoint of fuel plate burnout. A computer program is developed for the IBM 704 to aid in these calculations. The Bettis design departure from nucleate boiling (DNB) equation is used in conjunction with the LeTourneau and Grimble method of hot channel'' analysis in the development of the calculations. For cases where DNB occurs in the bulk boiling region, a modified Martinelli-Nelson twophase flow correlation and some experimental singlephase pressure drop data are employed. DNB for a typical operating condition of 550 deg F inlet temperature and 2500 psig is computed to check the code. The results of the sample calculation show that at a steady- state power level of 60 Mw (maximum design power) the minimum flow rate required to prevent DNB is approximately 8000 gpm. (auth)
Date: April 18, 1962
Creator: Dugone, J.
Object Type: Report
System: The UNT Digital Library
Low-temperature ceramic radioactive waste form characteriztion of supercalcine-based monazite-cement composites (open access)

Low-temperature ceramic radioactive waste form characteriztion of supercalcine-based monazite-cement composites

Simulated radioactive waste solidification by a lower temperature ceramic (cement) process is being investigated. The monazite component (simulated by NdPO/sub 4/) of supercalcine-ceramic has been solidified in cement and found to generate a solid form with low leachability. Several types of commercial cements and modifications thereof were used. No detectable release of Nd or P was found through characterizing the products of accelerated hydrothermal leaching at 473/sup 0/K (200/sup 0/C) and 30.4 MPa (300 bars) pressure.
Date: April 18, 1980
Creator: Roy, D. M.; Wakeley, L. D. & Atkinson, S. D.
Object Type: Report
System: The UNT Digital Library
Accident at Three Mile Island and its aftermath (open access)

Accident at Three Mile Island and its aftermath

Viewgraphs are presented that describe the Three Mile Island-2 reactor; the severe accident in the reactor; activity levels following the accident; and estimated costs associated with the accident.
Date: April 18, 1983
Creator: Malinauskas, A.P.
Object Type: Report
System: The UNT Digital Library
A High-Order Finite-Volume Algorithm for Fokker-Planck Collisions in Magnetized Plasmas (open access)

A High-Order Finite-Volume Algorithm for Fokker-Planck Collisions in Magnetized Plasmas

A high-order finite volume algorithm is developed for the Fokker-Planck Operator (FPO) describing Coulomb collisions in strongly magnetized plasmas. The algorithm is based on a general fourth-order reconstruction scheme for an unstructured grid in the velocity space spanned by parallel velocity and magnetic moment. The method provides density conservation and high-order-accurate evaluation of the FPO independent of the choice of the velocity coordinates. As an example, a linearized FPO in constant-of-motion coordinates, i.e. the total energy and the magnetic moment, is developed using the present algorithm combined with a cut-cell merging procedure. Numerical tests include the Spitzer thermalization problem and the return to isotropy for distributions initialized with velocity space loss cones. Utilization of the method for a nonlinear FPO is straightforward but requires evaluation of the Rosenbluth potentials.
Date: April 18, 2007
Creator: Xiong, Z; Cohen, R H; Rognlien, T D & Xu, X Q
Object Type: Article
System: The UNT Digital Library
Star-Formation in Low Radio Luminosity AGN from the Sloan Digital Sky Survey (open access)

Star-Formation in Low Radio Luminosity AGN from the Sloan Digital Sky Survey

We investigate faint radio emission from low- to high-luminosity Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their radio properties are inferred by coadding large ensembles of radio image cut-outs from the FIRST survey, as almost all of the sources are individually undetected. We correlate the median radio flux densities against a range of other sample properties, including median values for redshift, [O III] luminosity, emission line ratios, and the strength of the 4000{angstrom} break. We detect a strong trend for sources that are actively undergoing star-formation to have excess radio emission beyond the {approx} 10{sup 28} ergs s{sup -1} Hz{sup -1} level found for sources without any discernible star-formation. Furthermore, this additional radio emission correlates well with the strength of the 4000{angstrom} break in the optical spectrum, and may be used to assess the age of the star-forming component. We examine two subsamples, one containing the systems with emission line ratios most like star-forming systems, and one with the sources that have characteristic AGN ratios. This division also separates the mechanism responsible for the radio emission (star-formation vs. AGN). For both cases we find a strong, almost identical, correlation between [O III] and radio luminosity, …
Date: April 18, 2007
Creator: de Vries, W. H.; Hodge, J. A.; Becker, R. H.; White, R. L. & Helfand, D. J.
Object Type: Article
System: The UNT Digital Library
Preliminary Benchmarking Efforts and MCNP Simulation Results for Homeland Security (open access)

Preliminary Benchmarking Efforts and MCNP Simulation Results for Homeland Security

It is shown in this work that basic measurements made from well defined source detector configurations can be readily converted in to benchmark quality results by which Monte Carlo N-Particle (MCNP) input stacks can be validated. Specifically, a recent measurement made in support of national security at the Nevada Test Site (NTS) is described with sufficient detail to be submitted to the American Nuclear Society’s (ANS) Joint Benchmark Committee (JBC) for consideration as a radiation measurement benchmark. From this very basic measurement, MCNP input stacks are generated and validated both in predicted signal amplitude and spectral shape. Not modeled at this time are those perturbations from the more recent pulse height light (PHL) tally feature, although what spectral deviations are seen can be largely attributed to not including this small correction. The value of this work is as a proof-of-concept demonstration that with well documented historical testing can be converted into formal radiation measurement benchmarks. This effort would support virtual testing of algorithms and new detector configurations.
Date: April 18, 2008
Creator: Hayes, Robert
Object Type: Article
System: The UNT Digital Library
A Proposed Experimental Test of the Neutrino Theory (open access)

A Proposed Experimental Test of the Neutrino Theory

The experiment outlined in this proposal has the possibility of giving an answer to the important question, 'Does the neutrino exist'? It is unfortunate that at the present time, there is no convincing experimental that neutrinos exist. Two recent articles review the status of various experiments which could give information about neutrinos. In general, these experiments give results in agreement with the predictions of beta decay theory. But actually, if even the most complete of the 'recoil type' experiments could be performed satisfactorily, all that could be concluded would be the following: the energy and momentum relationships in beta decay are consistent with the theory that the known energy deficit is carried away by a single particle. But to emphasize the fact that this would not constitute a proof of the real existence of that particle, the following quotations from the review articles should be noted. Crane says, 'All of the evidence about the neutrino is, as already pointed out, indirect in character since neutrinos have not yet been caught after leaving the nucleus. It can, of course, be argued on very general grounds that, if energy is not conserved between nucleus and electron, momentum should not be expected to …
Date: April 18, 1949
Creator: Alvarez, Luis W.
Object Type: Report
System: The UNT Digital Library
ASC Predictive Science Academic Alliance Program Verification and Validation Whitepaper (open access)

ASC Predictive Science Academic Alliance Program Verification and Validation Whitepaper

None
Date: April 18, 2006
Creator: Klein, R.; Doebling, S.; Graziani, F.; Pilch, M. & Trucano, T.
Object Type: Report
System: The UNT Digital Library
Study of B Meson Decays with Excited eta and eta-prime Mesons (open access)

Study of B Meson Decays with Excited eta and eta-prime Mesons

Using 383 million B{bar B} pairs from the BABAR data sample, they report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to K{bar K}* or {eta}{pi}{pi} final states with mass in the range (1.2-1.8) GeV/c{sup 2}. They observe a significant enhancement at the low K{bar K}* invariant mass which is interpreted as B{sup +} {yields} {eta}(1475)K{sup +}, find evidence for the decay B{sup +} {yields} {eta}(1295)K{sup +}, and place upper limits on the decays B{sup +} {yields} {eta}(1405)K{sup +}, B{sup +} {yields} f{sub 1}(1285)K{sup +}, B{sup +} {yields} f{sub 1}(1420)K{sup +}, and B{sup +} {yields} {phi}(1680)K{sup +}.
Date: April 18, 2008
Creator: Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V. et al.
Object Type: Article
System: The UNT Digital Library
Fiberoptics-Based Instrumentation for Storage Ring BeamDiagnostics (open access)

Fiberoptics-Based Instrumentation for Storage Ring BeamDiagnostics

In several cases, coupling synchrotron light into opticalfibers can substantially facilitate the use of beam diagnosticinstrumentation, that measures longitudinal beam properties by detectingsynchrotron radiation. It has been discussed in [1]with some detail, howfiberoptics can bring the light at relatively large distances from theaccelerator, where a variety of devices can be used to measure beamproperties and parameters. Light carried on a fiber can be easilyswitched between instruments so that each one of them has 100 percent ofthe photons available, rather than just a fraction , when simultaneousmeasurements are not indispensable. From a more general point of view,once synchrotron light is coupled into the fiber, the vast array oftechniques and optoelectronic devices, developed by the telecommunicationindustry becomes available.In this paper we present the results of ourexperiments at the Advanced Light Source, where we tried to assess thechallenges and limitations of the coupling process and determine whatlevel of efficiency one can typically expect to achieve.
Date: April 18, 2007
Creator: Byrd, John M.; De Santis, Stefano & Yin, Yan
Object Type: Article
System: The UNT Digital Library
IMPACT OF SB4 TANK 40 DECANT AND ARP/MCU ADDITIONS WITH/WITHOUT ADDED CAUSTIC ON DWPF CPC PERFORMANCE (open access)

IMPACT OF SB4 TANK 40 DECANT AND ARP/MCU ADDITIONS WITH/WITHOUT ADDED CAUSTIC ON DWPF CPC PERFORMANCE

The Savannah River National Laboratory (SRNL) was requested to investigate the impact of decanting supernate from the Sludge Batch four (SB4) feed in Tank 40. The specific questions concerned the potential impact on the stoichiometric acid window determined for SB4 with respect to overall hydrogen generation rates, nitrite destruction in the Sludge Receipt and Adjustment Tank (SRAT) and the rheology of the sludge, SRAT product, and Slurry Mix Evaporator (SME) product slurries. The scope included considering an addition of sodium hydroxide to Tank 40 to partially offset the sodium lost during decanting as well as considering the impact of bounding quantities of Actinide Removal Process (ARP) feed and Modular Caustic-Side Solvent Extraction Unit (MCU) feed on these same parameters. Simulated SB4 waste was first adjusted to match the dilution that has occurred in Tank 40 during the initial period of SB4 operations in the DWPF. The adjusted simulant was decanted an equivalent of 100,000 gallons relative to 413,740 gallons projected supernate volume. The decanted simulant was divided into two equal parts. One part received an addition of sodium hydroxide to increase the Na{sub 2}O content of the calcined sludge solids by about 3%. The baseline decanted simulant and caustic adjusted …
Date: April 18, 2008
Creator: Koopman, D; David Best, D & Frances Williams, F
Object Type: Report
System: The UNT Digital Library
Strontium and barium iodide high light yield scintillators (open access)

Strontium and barium iodide high light yield scintillators

Europium-doped strontium and barium iodide are found to be readily growable by the Bridgman method and to produce high scintillation light yields.
Date: April 18, 2008
Creator: Moses, William W; Cherepy, Nerine; Hull, Giulia; Drobshoff, Alexander; Payne, Stephen; van Loef, Edgar et al.
Object Type: Article
System: The UNT Digital Library
The Kinematics of Molecular Cloud Cores in the Presence of Driven and Decaying Turbulence: Comparisons with Observations (open access)

The Kinematics of Molecular Cloud Cores in the Presence of Driven and Decaying Turbulence: Comparisons with Observations

In this study we investigate the formation and properties of prestellar and protostellar cores using hydrodynamic, self-gravitating Adaptive Mesh Refinement simulations, comparing the cases where turbulence is continually driven and where it is allowed to decay. We model observations of these cores in the C{sup 18}O(2 {yields} 1), NH{sub 3}(1,1), and N{sub 2}H{sup +} (1 {yields} 0) lines, and from the simulated observations we measure the linewidths of individual cores, the linewidths of the surrounding gas, and the motions of the cores relative to one another. Some of these distributions are significantly different in the driven and decaying runs, making them potential diagnostics for determining whether the turbulence in observed star-forming clouds is driven or decaying. Comparing our simulations with observed cores in the Perseus and {rho} Ophiuchus clouds shows reasonably good agreement between the observed and simulated core-to-core velocity dispersions for both the driven and decaying cases. However, we find that the linewidths through protostellar cores in both simulations are too large compared to the observations. The disagreement is noticeably worse for the decaying simulation, in which cores show highly supersonic infall signatures in their centers that decrease toward their edges, a pattern not seen in the observed regions. …
Date: April 18, 2008
Creator: Offner, S R; Krumholz, M R; Klein, R I & McKee, C F
Object Type: Report
System: The UNT Digital Library
Interference effect in elastic parton energy loss in a finitemedium (open access)

Interference effect in elastic parton energy loss in a finitemedium

Similar to the radiative parton energy loss due to gluonbremsstrahlung, elastic energy loss of a parton undergoing multiplescattering in a finite medium is demonstrated to be sensitive tointerference effect. The interference between amplitudes of elasticscattering via a gluon exchange and that of gluon radiation reduces theeffective elastic energy loss in a finite medium and gives rise to anon-trivial length dependence. The reduction is most significant for apropagation length L<4/\pi T in a medium with a temperature T. Thoughthe finite size effect is not significant for the average partonpropagation in the most central heavy-ion collisions, it will affect thecentrality dependence of its effect on jet quenching.
Date: April 18, 2005
Creator: Wang, Xin-Nian
Object Type: Article
System: The UNT Digital Library
Stewarding a Reduced Stockpile (open access)

Stewarding a Reduced Stockpile

The future of the US nuclear arsenal continues to be guided by two distinct drivers: the preservation of world peace and the prevention of further proliferation through our extended deterrent umbrella. Timely implementation of US nuclear policy decisions depends, in part, on the current state of stockpile weapons, their delivery systems, and the supporting infrastructure within the Department of Defense (DoD) and the Department of Energy's National Nuclear Security Administration (NNSA). In turn, the present is a product of past choices and world events. Now more than ever, the nuclear weapons program must respond to the changing global security environment and to increasing budget pressures with innovation and sound investments. As the nation transitions to a reduced stockpile, the successes of the Stockpile Stewardship Program (SSP) present options to transition to a sustainable complex better suited to stockpile size, national strategic goals and budgetary realities. Under any stockpile size, we must maintain essential human capital, forefront capabilities, and have a right-sized effective production capacity. We present new concepts for maintaining high confidence at low stockpile numbers and to effectively eliminate the reserve weapons within an optimized complex. We, as a nation, have choices to make on how we will achieve …
Date: April 18, 2008
Creator: Goodwin, B. T. & Mara, G.
Object Type: Article
System: The UNT Digital Library
Can Handheld Plastic Detectors Do Both Gamma and Neutron Isotopic Identification with Directional Source Location? (open access)

Can Handheld Plastic Detectors Do Both Gamma and Neutron Isotopic Identification with Directional Source Location?

This paper demonstrates, through MCNPX simulations, that a compact hexagonal array of detectors can be utilized to do both gamma isotopic identification (ID) along with neutron identification while simultaneously finding the direction of the source relative to the detector array. The detector array itself is composed of seven borated polyvinyl toluene (PVT) hexagonal light pipes approximately 4 inches long and with a 1.25 inch face-to-face thickness assembled in a tight configuration. The gamma ID capability is realized through judicious windowing algorithms as is the neutron spectral unfolding. By having multiple detectors in different relative positions, directional determination of the source can be realized. By further adding multiplicity counters to the neutron counts, fission events can be measured.
Date: April 18, 2008
Creator: Hayes, Robert
Object Type: Article
System: The UNT Digital Library
Robotic weld overlay coatings for erosion control (open access)

Robotic weld overlay coatings for erosion control

Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.
Date: April 18, 1993
Creator: Levin, B. F.; Dupont, J. N. & Marder, A. R.
Object Type: Report
System: The UNT Digital Library
Welding stainless steels for structures operating at liquid helium temperature (open access)

Welding stainless steels for structures operating at liquid helium temperature

Superconducting magnets for fusion energy reactors require massive monolithic stainless steel weldments which must operate at extremely low temperatures under stresses approaching 100 ksi (700 MPa). A three-year study was conducted to determine the feasibility of producing heavy-section welds having usable levels of strength and toughness at 4.2/sup 0/K for fabrication of these structures in Type 304LN plate. Seven welding processes were evaluated. Test weldments in full-thickness plate were made under severe restraint to simulate that of actual structures. Type 316L filler metal was used for most welds. Welds deposited under some conditions and which solidify as primary austenite have exhibited intergranular embrittlement at 4.2/sup 0/K. This is believed to be associated with grain boundary metal carbides or carbonitrides precipitated during reheating of already deposited beads by subsequent passes. Weld deposits which solidify as primary delta ferrite appear immune. Through use of fully austenitic filler metals of low nitrogen content under controlled shielded metal arc welding conditions, and through use of filler metals solidifying as primary delta ferrite where only minimum residuals remain to room temperature, welds of Type 316L composition have been made with 4.2K yield strength matching that of Type 304LN plate and acceptable levels of soundness, ductility …
Date: April 18, 1980
Creator: Witherell, C.E.
Object Type: Article
System: The UNT Digital Library