Gamma-ray measurements at the WNR white neutron source (open access)

Gamma-ray measurements at the WNR white neutron source

Photon production data have been acquired in the incident neutron energy range, 1 < E{sub n} < 400 MeV, for a number of target nuclei, gamma-ray energy ranges, and reactions, using the continuous-energy neutron beam of the WNR facility at Los Alamos. Gamma-ray production measurements using high resolution Ge detectors have been employed for gamma-rays in the energy range, 0.1 < E{sub {gamma}} < 10 MeV. These measurements allow identification of reactions from the known energies of the gamma-ray transitions between low-lying states in the final nucleus. Some of the targets studied include: N, O, Al, Na, {sup 56}Fe, and {sup 207,208}Pb. These data are useful both for testing nuclear reaction models at intermediate energies and for numerous applied purposes. BGO detectors do not have the good energy resolution of Ge detectors, but have much greater detection efficiency for gamma rays with energies greater than a few MeV. We have used an array of 5 BGO detectors to measure cross sections and angular distributions for photon production from C and N. A large, well-shielded BGO detector has been used to measure fast neutron capture in the giant resonance region with a maximum gamma-ray energy of 52 MeV. We present results …
Date: December 31, 1994
Creator: Nelson, R. O.; Wender, S. A. & Mayo, D. R.
System: The UNT Digital Library
Proceedings of the workshop on future hadron facilities in the US (open access)

Proceedings of the workshop on future hadron facilities in the US

This report discusses the following topics on future hadron facilities: Workshop on future hadron facilities in the US; 30 {times} 30 TeV-summary report; A high luminosity, 2 {times} 2 TeV collider in the tevatron tunnel; magnets working group; cryogenics discussion; vacuum report; antiproton source production; injector working group; interaction region working group; lattice/beam dynamics working group; LEBT for high-luminosity colliders; some notes on long-range beam-beam effects for the 2TeV collider; synchrotron radiation masks for high energy proton accelerators. Emittance preservation in a proton synchrotron; beam-beam interaction effects on betatron tunes; analytic solutions for phase trombone modules; and chromatic corrections of RHIC when one or two insertions is at {Beta}* = 0.5m.
Date: December 31, 1994
Creator: unknown
System: The UNT Digital Library
Optical properties of fractal nanocomposites (open access)

Optical properties of fractal nanocomposites

Optical prossesses in nanostructured fractal composites are shown to be strongly enhanced. The enhancement occurs because of a localization of dipolar eigenmodes in subwavelength areas.
Date: December 31, 1994
Creator: Markel, V. A.; Kim, W.; Armstrong, R.; Shalaev, V. & Stechel, E. B.
System: The UNT Digital Library
On the prior probabilities for two-stage Bayesian estimates (open access)

On the prior probabilities for two-stage Bayesian estimates

The method of Bayesian inference is reexamined for its applicability and for the required underlying assumptions in obtaining and using prior probability estimates. Two different approaches are suggested to determine the first-stage priors in the two-stage Bayesian analysis which avoid certain assumptions required for other techniques. In the first scheme, the prior is obtained through a true frequency based distribution generated at selected intervals utilizing actual sampling of the failure rate distributions. The population variability distribution is generated as the weighed average of the frequency distributions. The second method is based on a non-parametric Bayesian approach using the Maximum Entropy Principle. Specific features such as integral properties or selected parameters of prior distributions may be obtained with minimal assumptions. It is indicated how various quantiles may also be generated with a least square technique.
Date: December 31, 1992
Creator: Kohut, P.
System: The UNT Digital Library
Dual-benefit technologies at Sandia National Laboratories (open access)

Dual-benefit technologies at Sandia National Laboratories

What does the pulp and paper industry have in common with the desert southwest and nuclear weapons? As a representative of one of the Nations three nuclear weapons design laboratories (Los Alamos National Laboratory, Livermore National Laboratory and Sandia National Laboratories), my goal is to identify ``dual-benefit`` technologies where codevelopment will both strengthen the nation`s competitive position and enhance national security. In development of this presentation, I found more common elements than I could possibly survey in this brief period.
Date: December 31, 1993
Creator: Schaefer, D. W.
System: The UNT Digital Library
Study of nucleation and growth in Al-Zn alloys using TEM (open access)

Study of nucleation and growth in Al-Zn alloys using TEM

Nucleation and growth studies were conducted on Al-Zn alloys at several temperatures using transmission electron microscopy (TEM) with an in-situ furnace. The value of the critical undercooling was established by noting the lowest temperature at which precipitates were no longer observed, following a quench into the two-phase metastable region. These results were compared with the Langer-Schwartz model of nucleation and growth in which it is predicted that the half-completion time (i.e, the time required for the supersaturation to reach half its initial value) diverges for initial supersaturations which are higher than those predicted by the classical nucleation theory.
Date: December 31, 1993
Creator: Sundar, G.; Hoyt, J. J.; Kenik, E. A. & Spooner, S.
System: The UNT Digital Library
Target station design for a 1 MW pulsed spallation neutron source (open access)

Target station design for a 1 MW pulsed spallation neutron source

Target stations are vital components of the 1 MW, next generation spallation neutron source proposed for LANSCE. By and large, target stations design determines the overall performance of the facility. Many traditional concepts will probably have to be rethought, and many new concepts will have to be put forward to meet the 1 MW challenge. This article gives a brief overview of the proposed neutron spallation source from the target station viewpoint, as well as the general philosophy adopted for the design of the LANSCE-II target stations. Some of the saliant concepts and features envisioned for LANSCE-II are briefly described.
Date: December 31, 1993
Creator: Russell, G. J.; Baker, G. D. & Brewton, R. J.
System: The UNT Digital Library
In vivo studies in NCT with a boronated porphyrin and tumor growth delay as an end point (open access)

In vivo studies in NCT with a boronated porphyrin and tumor growth delay as an end point

The robust carrying capacity of the porphyrin molecule and its propensity for localizing in tumor justified the synthesizing of a porphyrin labeled with boron for use in BNCT. However, problems associated with poor solubility impeded the utility of the molecule. Until BOPP was synthesized porphyrins were promising, but impractical. After in vitro experiments had demonstrated the biological efficacy of BOPP and had confirmed its intracellular localizing ability in vivo studies were carried out using mice. Irradiation of KHJJ murine mammary carcinoma to the TCD{sub 50} in a single fraction was precluded since this whole body dose is lethal. This problem was overcome by the use of radiation. BOPP was administered either as three 0.5 ml injections per day over two days or by continuous i.v. infusion, 2 ml per day over three days for a total dose of about 42 {mu}g {sup 10}B/gbw. Boron-10 distribution in the tumor at the time of irradiation was {approximately}20 {mu}g.
Date: December 31, 1992
Creator: Laster, B. H.; Kahl, S. B.; Warkentien, Lynne & Bond, V. P.
System: The UNT Digital Library
Buried Waste Integrated Demonstration lessons learned: 1993 technology demonstrations (open access)

Buried Waste Integrated Demonstration lessons learned: 1993 technology demonstrations

An integrated technology demonstration was conducted by the Buried Waste Integrated Demonstration (BWID) at the Idaho National Engineering Laboratory Cold Test Pit in the summer of 1993. This program and demonstration was sponsored by the US Department of Energy Office of Technology Development. The demonstration included six technologies representing a synergistic system for the characterization and retrieval of a buried hazardous waste site. The integrated technology demonstration proved very successful and a summary of the technical accomplishments is presented. Upon completion of the integrated technology demonstration, cognizant program personnel participated in a lessons learned exercise. This exercise was conducted at the Simplot Decision Support Center at Idaho State University and lessons learned activity captured additional information relative to the integration of technologies for demonstration purposes. This information will be used by BWID to enhance program planning and strengthen future technology demonstrations.
Date: December 31, 1994
Creator: Kostelnik, K. M. & Owens, K. J.
System: The UNT Digital Library
MRIVIEW: An interactive computational tool for investigation of brain structure and function (open access)

MRIVIEW: An interactive computational tool for investigation of brain structure and function

MRIVIEW is a software system which uses image processing and visualization to provide neuroscience researchers with an integrated environment for combining functional and anatomical information. Key features of the software include semi-automated segmentation of volumetric head data and an interactive coordinate reconciliation method which utilizes surface visualization. The current system is a precursor to a computational brain atlas. We describe features this atlas will incorporate, including methods under development for visualizing brain functional data obtained from several different research modalities.
Date: December 31, 1993
Creator: Ranken, D. & George, J.
System: The UNT Digital Library
Analysis of the OECD-LOFT International Standard Problem 31 using SCDAP/RELAP5/MOD3 (open access)

Analysis of the OECD-LOFT International Standard Problem 31 using SCDAP/RELAP5/MOD3

The CORA-13 bundle heating and melting experiment performed at the Kernforechungszentrum, Karlaruhe, (KfK) was analyzed at the Idaho National Engineering Laboratory (INEL) using SCDAP/RELAP5/MOD3. This analysis was part of a systematic assessment of SCDAP/RELAP5/MOD3 for the US Nuclear Regulatory Commission to (a) evaluate the variances between calculated and observed behavior, (b) identify outstanding modeling deficiencies, and (c) to evaluate the impact of ongoing modeling improvements. A brief discussion of the CORA-13 experiment including a description of the facility, important test conditions, and comparisons with other CORA experimental conditions and results is provided in this report. This report describes the results of the SCDAP/RELAPS/MOD3 analysis including a description of the SCDAP/RELAPS model of the facility, base case results, sensitivity results, and a comparison with other SCDAP/RELAP5/MOD3 code-to-data comparisons.
Date: December 31, 1992
Creator: Hohorst, J. K. & Allison, C. M.
System: The UNT Digital Library
Measurement of cesium and mercury emissions from the vitrification of simulated high level radioactive waste (open access)

Measurement of cesium and mercury emissions from the vitrification of simulated high level radioactive waste

In the Defense Waste Processing Facility at the Savannah River Site, it is desired to measure non-radioactive cesium in the offgas system from the glass melter. From a pilot scale melter system, offgas particulate samples were taken on filter paper media and analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The ICP-MS method proved to be sufficiently sensitive to measure cesium quantities as low as 0.135 {mu}g, with the sensitivity being limited by the background cesium present in the filter paper. This sensitivity allowed determination of cesium decontamination factors for four of the five major components of the offgas system. In addition, total particulate measurements were also made. Measurements of mercury decontamination factors were made on the same equipment; the results indicate that most of the mercury in the offgas system probably exists as elemental mercury and HgCl{sub 2}, with some HgO and Hg{sub 2}Cl{sub 2}. The decontamination factors determined for cesium, total particulate, and mercury all compared favorably with the design values.
Date: December 31, 1992
Creator: Zamecnik, J. R.
System: The UNT Digital Library
Distributions of spontaneous chromosomal aberrations and of spontaneous and induced SCE and micronuclei in peripheral lymphocytes from a human population (open access)

Distributions of spontaneous chromosomal aberrations and of spontaneous and induced SCE and micronuclei in peripheral lymphocytes from a human population

Biomonitoring of human populations for exposure to genotoxic/clastogenic agents in the environment or the workplace must depend upon statistical tests for elevations in the frequencies of the biological endpoints being monitored, usually chromosomal aberrations (CA), micronuclei (MN), or sister chromatid exchanges (SCE) in peripheral blood lymphocytes. Statistical tests are based, in turn, upon certain assumptions regarding the distribution of the test statistic. When they are often not recognized as such, tests of significance can be in error, and any conclusion drawn that there is or is not a statistically significant difference between one population sample and another maybe erroneous. In population monitoring this means either false negatives or false positives can result and it is hard to know which is worse. Furthermore, even the intelligent design of studies whose object is to test for an elevated level in an exposed population must depend upon prior knowledge of the nature of both spontaneous and induced response; if variance is large enough, a given-sized study might be inconclusive, and an adequate study simply too large-to be practical.
Date: December 31, 1992
Creator: Bender, M. A. & Setlow, R. B.
System: The UNT Digital Library
An object model for genome information at all levels of resolution (open access)

An object model for genome information at all levels of resolution

An object model for genome data at all levels of resolution is described. The model was derived by considering the requirements for representing genome related objects in three application domains: genome maps, large-scale DNA sequencing, and exploring functional information in gene and protein sequences. The methodology used for the object-oriented analysis is also described.
Date: December 31, 1993
Creator: Honda, S.; Parrott, N. W.; Smith, R. & Lawrence, C.
System: The UNT Digital Library
Binary-binary collisions involving main-sequence stars, white dwarfs and neutron stars in globular clusters (open access)

Binary-binary collisions involving main-sequence stars, white dwarfs and neutron stars in globular clusters

We consider collisions between dynamically-evolved primordial binaries consisting of main-sequence stars, white dwarfs and neutron stars in globular clusters. In our four-body binary-binary scattering experiments, we allow stars to ``stick`` if they pass close enough to each other, which leads to the formation of a wide variety of exotic objects. Most of these objects have binary companions. Also, relatively clean exchange interactions can produce binaries containing neutron stars that eventually receive material from their companions. Such systems will be observable as X-ray binaries.
Date: December 31, 1993
Creator: Leonard, P. J. T. & Davies, M. B.
System: The UNT Digital Library
Long term plutonium solubility and speciation studies in a synthetic brine (open access)

Long term plutonium solubility and speciation studies in a synthetic brine

The rate at which elements can be transported in groundwater systems is governed in part by the solubility of the element in the groundwater. This report documents plutonium solubility experiments in a brine simulant relevant to the Waste Isolation Pilot Plant. Approximately 1 to 2.5 mL of five stock solutions containing single oxidation states of plutonium (Pu(IV)-polymer, Pu{sup 3+}, Pu{sup 4+}, PuO{sub 2}{sup +}, and PuO{sub 2}{sup 2+}) were added to {approximately}75 mL of synthetic H-17 Brine in five reaction vessels. Initial plutonium concentrations ranged from 1.3 {times} l0{sup {minus}4} to 5.l {times} l0{sup {minus}4} M (moles per liter) total plutonium. Because these initial concentrations were far above the plutonium solubility limit in H-17 Brine, plutonium-containing solids precipitated. Aqueous plutonium concentrations were measured over time until steady-state was reached, requiring over 300 days in H-17 Brine.
Date: December 31, 1993
Creator: Nitsche, Heino; Roberts, K. & Xi, Ruihua
System: The UNT Digital Library
Recovery, transport, and disposal of CO{sub 2} from an integrated gasification combined-cycle power plant (open access)

Recovery, transport, and disposal of CO{sub 2} from an integrated gasification combined-cycle power plant

Initiatives to limit CO{sub 2} emissions have drawn considerable interest to integrated gasification combined-cycle (IGCC) power generation, a process that reduces CO{sub 2} production and is amenable to CO{sub 2} capture. This paper presents a comparison of energy systems that encompass fuel supply, an IGCC system, CO{sub 2} recovery using commercial technologies, CO{sub 2} transport by pipeline, and land-based sequestering in geological reservoirs. The intent is to evaluate the energy efficiency impacts of controlling CO{sub 2} in such a system, and to provide the CO{sub 2} budget, or an equivalent CO{sub 2} budget, associated with each of the individual energy-cycle steps. The value used for the equivalent CO{sub 2} budget is 1 kg CO{sub 2}/kWh. The base case for the comparison is a 458-MW IGCC system using an air-blown Kellogg Rust Westinghouse (KRW) agglomerating fluidized-bed gasifier, Illinois No.6 bituminous coal, and in-bed sulfur removal. Mining, transportation, and preparation of the coal and limestone result in a net electric power production of 448 MW with a 0.872 kg/kWh CO{sub 2} release rate. For comparison, the gasifier output was taken through a water-gas shift to convert CO to CO{sub 2}, and processed in a Selexol unit to recover CO{sub 2} prior to …
Date: December 31, 1993
Creator: Livengood, C. D.; Doctor, R. D.; Molburg, J. C.; Thimmapuram, P. & Berry, G. F.
System: The UNT Digital Library
Gadolinium as an element for neutron capture therapy (open access)

Gadolinium as an element for neutron capture therapy

At BNL, preparations are being made to test in vitro compounds containing Gd and compare their response to the response of GD-DTPA to determine if one or several compounds can be located that enter the cells and enhance the Auger effect. Two similar rotators with positions for cell vials that have been constructed for these tests. The first rotator is made of only paraffin which simulates healthy tissue and provides control curves. The second rotator has 135 ppM of Gd-157 in the paraffin to simulate a Gd loaded tumor. Cells are irradiated in vials in the paraffin rotator and in the Gd-paraffin rotator at the epithermal beam of the Brookhaven Medical Research Reactor (BMRR). This produces an irradiation similar to what a patient would receive In an actual treatment. A combination of irradiations are made with both rotators; with no Gd compound or IdUrd In the cell media, with only Gd compound in the cell media and with both Gd compound and IdUrd in the cell media. The first set shows the effects of gamma rays from the H(n,gamma) reaction and the prompt gamma rays from capture of neutrons by Gd. The second set shows if there is any effect …
Date: December 31, 1992
Creator: Brugger, R. M.; Liu, H. B.; Laster, B. H.; Gordon, C. R.; Greenberg, D. D. & Warkentien, L. S.
System: The UNT Digital Library
DOE pollution prevention in the 21st century. Proceedings (open access)

DOE pollution prevention in the 21st century. Proceedings

This CD-ROM contains the proceedings from the DOE Pollution Prevention in the 21st Century Conference XII held July 9-11, 1996. Topics included model facilities, federal and NEPA stakeholders, microchemistry, source 4 solvents and reduction, education and outreach planning, return on investment, energy management, decontamination and decommissioning, planning and regulations, environmental restoration, solid waste, recycling, affirmative procurement in the executive branch, construction and demolition, international and ISO 14000, and poster sessions.
Date: December 31, 1996
Creator: unknown
System: The UNT Digital Library
Projectile Transverse Motion and Stability in Electromagnetic Induction Launchers (open access)

Projectile Transverse Motion and Stability in Electromagnetic Induction Launchers

The transverse motion of a projectile in an electromagnetic induction launcher is considered. The equations of motion for translation and rotation are derived assuming a rigid projectile and a flyway restoring force per unit length that is proportional to the local displacement. Linearized transverse forces and torques due to energized coils are derived for displaced or tilted armature elements based on a first order perturbation method. The resulting equations of motion for a rigid projectile composed of multiple elements in a multi-coil launcher are analyzed as a coupled oscillator system of equations and a simple linear stability condition is derived. The equations of motion are incorporated into the 2-D Slingshot circuit code and numerical solutions for the transverse motion are obtained. For a launcher with a 10 cm bore radius with a 40 cm long solid armature, we find that stability is achieved with a restoring force (per unit length) constant of k {approx} 1 {times} 10{sup 8} N/m{sup 2}. For k = 1.5 {times} 10{sup 8} N/m{sup 2} and sample coil misalignment modeled as a sine wave of 1 mm amplitude at wavelengths of one or two meters, the projectile displacement grows to a maximum of 4 mm. This …
Date: December 31, 1993
Creator: Shokair, I. R.
System: The UNT Digital Library
A low cost igniter utilizing an SCB and titanium sub-hydride potassium perchlorate pyrotechnic (open access)

A low cost igniter utilizing an SCB and titanium sub-hydride potassium perchlorate pyrotechnic

A conventional NSI (NASA standard initiator) normally employs a hot-wire ignition element to ignite ZPP (zirconium potassium perchlorate). With minor modifications to the interior of a header similar to an NSI device to accommodate an SCB (semiconductor bridge), a low cost initiator was obtained. In addition, the ZPP was replaced with THKP (titanium subhydride potassium perchlorate) to obtain increased overall gas production and reduced static-charge sensitivity. This paper reports on the all-fire and no-fire levels obtained and on a dual mix device that uses THKP as the igniter mix and a thermite as the output mix.
Date: December 31, 1993
Creator: Bickes, R. W. Jr.; Grubelich, M. C.; Hartman, J. K.; McCampbell, C. B. & Churchill, J. K.
System: The UNT Digital Library
Status of nuclear data for ITER applications (open access)

Status of nuclear data for ITER applications

As the development of a near-term fusion reactor, such as the International Thermonuclear Experimental Reactor (ITER), enters the engineering design activity phase, one of the essential elements leading to the successful design, construction and operation of such a reactor is nuclear data. High quality nuclear data for all reactor materials relevant to ITER will be required in order to assess the nuclear performance, radiation damage, and safety and environmental aspects of all reactor components. In this paper the authors review the current ITER design, noting which materials and associated nuclear data are important in the various reactor components. They also review the contents of the Fusion Evaluated Nuclear Data Library (FENDL) accepted for use by ITER, and identify materials for which nuclear data improvements are required.
Date: December 31, 1994
Creator: Larson, D. C.; Cheng, E. T.; Mann, F. M. & Saji, G.
System: The UNT Digital Library
Realtime structural electrochemistry of platinum clusters using dispersive XAFS (open access)

Realtime structural electrochemistry of platinum clusters using dispersive XAFS

Chemical reference tables state that the standard potential for the reaction of Pt with water, Pt + 2H{sub 2}O {r_arrow} Pt(OH){sub 2} + 2H{sup +} + 2e{sup {minus}}, is 0.98 V, and electrochemical studies propose that this reaction may occur at potentials as low as 0.8 V. Using dispersive x-ray absorption fine-structure (XAFS) spectroscopy, the authors have directly probed the structural evolution of a Pt catalyst operating in-situ in a polymer electrolyte fuel cell during cyclic voltammetry. The changes in the number of Pt and O nearest-neighbors and the Pt charge demonstrate a close correspondence with features in the voltammogram. Because dispersive XAFS is very sensitive to detecting structural changes, they have been able to detect the presence of chemisorbed oxygen at potentials of 0.6--0.9 V in the anodic sweep. Since double-layer charging is regarded as the only process in this region for bulk Pt, these results may reflect a limitation of previous (indirect) studies on Pt electrochemistry, or they may indicate that these clusters are different from their bulk metal counterparts. Exploiting the time-resolving capability of dispersive XAFS, they also monitored changes in the Pt charge and the number of O and Pt nearest-neighbors during the electrochemical oxidation and …
Date: December 31, 1993
Creator: Allen, P. G.; Conradson, S. D.; Wilson, M. S.; Gottesfeld, S. & Raistrick, I. D.
System: The UNT Digital Library
Spatial intensity profiling of an industrial laser welding system (open access)

Spatial intensity profiling of an industrial laser welding system

A investigation was conducted to devise a method to sense the laser beam intensity profile of an industrial laser welding system. The research focuses on monitoring methods and assessing locations within the system where data can be taken which reveal the relationship between the laser beam intensity profile and the input system parameters of the laser beam welding process. Emphasis has been placed on the configuration of a distributed computing environment to acquire, analyze and display the results of the sensed beam profile. Conventional image processing techniques are demonstrated. It was found that a distributed computing environment was useful for processing the large volumes of data generated by this process characterization method, and the distributed computing environment provided the computing power required for computationally intensive analysis and display techniques. The mathematical techniques used to discriminate one data set from another and relate the results to processing conditions are discussed.
Date: December 31, 1991
Creator: Milewski, J. O.
System: The UNT Digital Library