Average Total Neutron Cross Section OF 233U, 235U AND 239Pu from ORELA Transmission Measurements and Statistical Analysis of the Data (open access)

Average Total Neutron Cross Section OF 233U, 235U AND 239Pu from ORELA Transmission Measurements and Statistical Analysis of the Data

The average total neutron cross sections of {sup 233}U, {sup 235}U, and {sup 239}Pu were obtained from transmission measurements in the unresolved resonance region up to several hundred keV neutron energy. The method used for the calculation of the self-shielding effect is described. A statistical model analysis of the results was performed and the s-, p- and d-wave neutron strength functions were obtained.
Date: August 24, 2001
Creator: Derrien, H.
Object Type: Article
System: The UNT Digital Library
Comparative Study of Surface-lattice-site Resolved Neutralization of Slow Multicharged Ions during Large-angle Quasi-binary Collisions with Au(110): Simulation and Experiment (open access)

Comparative Study of Surface-lattice-site Resolved Neutralization of Slow Multicharged Ions during Large-angle Quasi-binary Collisions with Au(110): Simulation and Experiment

In this article we extend our earlier studies of the azimuthal dependences of low energy projectiles scattered in large angle quasi-binary collisions from Au(110). Measurements are presented for 20 keV Ar{sup 9+} at normal incidence, which are compared with our earlier measurements for this ion at 5 keV and 10{sup 0} incidence angle. A deconvolution procedure based on MARLOWE simulation results carried out at both energies provides information about the energy dependence of projectile neutralization during interactions just with the atoms along the top ridge of the reconstructed Au(110) surface corrugation, in comparison to, e.g., interactions with atoms lying on the sidewalls. To test the sensitivity of the agreement between the MARLOWE results and the experimental measurements, we show simulation results obtained for a non-reconstructed Au(110) surface with 20 keV Ar projectiles, and for different scattering potentials that are intended to simulate the effects on scattering trajectory of a projectile inner shell vacancy surviving the binary collision, In addition, simulation results are shown for a number of different total scattering angles, to illustrate their utility in finding optimum values for this parameter prior to the actual measurements.
Date: August 24, 2001
Creator: Meyer, F.W.
Object Type: Article
System: The UNT Digital Library
Defense Management: Better Guidance Needed in Selecting Operating Methods for Name-Brand, Fast-Food Restaurants (open access)

Defense Management: Better Guidance Needed in Selecting Operating Methods for Name-Brand, Fast-Food Restaurants

A letter report issued by the General Accounting Office with an abstract that begins "The military exchange services operate a wide range of retail activities, such as department stores, florist shops, barber and beauty shops, gas stations, and restaurants. Hamburger restaurants represent a major segment of the exchange services' name-brand, fast-food sales. The exchange services use either a direct or an indirect method to operate these restaurants. Under the direct method, the exchange service enters into a franchise agreement with a name-brand company to sell its product on a military installation. As the franchisee, the exchange service builds and operates the restaurant and directly employs and trains the personnel. In turn, the exchange service receives all of the revenues and profits and usually pays the company a licensing fee plus a percentage of the restaurant's sales. Under the indirect method, the exchange service contracts with a name-brand company that, in turn, builds the restaurant and either operates it as a company restaurant or provides a licensed operator. The company or its licensed operator hires, trains, and pays the restaurant personnel and usually pays annual fees and commissions to the exchange service on the basis of restaurant's sales. Under this agreement, …
Date: August 24, 2001
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Development of Commercial Applications of a FAPY Alloy (open access)

Development of Commercial Applications of a FAPY Alloy

The Fe-16 at. (8.5 wt) % Al alloy, known as FAPY, has been identified as a superior material for heating element applications. However, while the 15-lb heats melted at the Oak Ridge National Laboratory (ORNL) could be processed into wire, the large heat melted at Hoskins Manufacturing Company (Hoskins) could not be processed under commercial processing conditions. The primary objective of the Cooperative Research and Development Agreement (CRADA) was to demonstrate that wire of the FAPY alloy could be produced under commercial conditions from air-induction-melted (AIM) heats. The specific aspects of this CRADA included: (1) Melting 15-lb heats by AIM or vacuum-induction melting (VIM) at ORNL. (2) Development of detailed processing steps including warm drawing and annealing temperature and time during cold-drawing steps. (3) Melting of 1400-lb heats at Hoskins by the Exo-Melt{trademark} process and their chemical analysis and microstructural characterization. (4) Development of tensile properties of sections of ingots from the large heats in the ascast, hot-worked, and hot- and cold-worked conditions. (5) Microstructural characterization of cast and wrought structures and the fractured specimens. (6) Successful demonstration of processing of AIM heats at Hoskins to heating element wire. The aspects of this CRADA listed above have demonstrated that the …
Date: August 24, 2001
Creator: Sikka, VK
Object Type: Report
System: The UNT Digital Library
Effect of partially reacting Nb{sub 3}Sn before magnet winding on the strand critical current (open access)

Effect of partially reacting Nb{sub 3}Sn before magnet winding on the strand critical current

Nb{sub 3}Sn is currently the material most commonly foreseen for the development of high field superconducting magnets. This is done by either the wind and react technique, usually used for compact magnets like accelerator magnets, or the react and wind technique, more common on large scale magnets. In both cases, a thorough understanding of the Cu-Sn system diffusion and phase formation processes is necessary to optimize the Nb{sub 3}Sn reaction cycle. Attention has to be paid to both the superconducting performance and the prevention of thermally induced damage of the final produced conductor. The formation of the eta and epsilon phases of the Cu-Sn phase diagram were investigated as a function of time and temperature. Wherever possible, the activation energies and diffusion coefficients were calculated. The feasibility of winding partly reacted cables to reduce the manufacturing time was also explored. Nb{sub 3}Sn strands have been partially reacted to convert the Sn to the eta and epsilon phases of the Cu-Sn phase diagram, then plastically strained to figure out a cabling and/or a winding degradation. After completion of the reaction cycle, the critical current was measured and compared with that obtained with an uninterrupted cycle.
Date: August 24, 2001
Creator: al., J.M. Rey et
Object Type: Article
System: The UNT Digital Library
The Emergency Food Assistance Program and Emergency Feeding Needs (open access)

The Emergency Food Assistance Program and Emergency Feeding Needs

This report contains the emergency food assistance program and emergency feeding needs.
Date: August 24, 2001
Creator: Richardson, Joe & Porter, Donna V.
Object Type: Report
System: The UNT Digital Library
Energy Tax Policy (open access)

Energy Tax Policy

President Bush has issued a comprehensive energy policy initiative, which includes limited energy tax measures; the Administration has criticized such measures as being inconsistent with its free market philosophy. Several of the issues that drove energy policy and energy tax policy during the 106th Congress are extant: 1) tax incentives to increase the supply of oil and gas; 2) energy tax issues relating to energy conservation and energy efficiency; 3) energy tax issues relating to alternative fuels; 4) energy taxes/subsidies and residential energy costs; and 5) issues relating to electricity restructuring. In addition, there are certain energy tax provisions that are either expiring or are time-sensitive that the 107th Congress may choose to take action on.
Date: August 24, 2001
Creator: Lazzari, Salvatore
Object Type: Report
System: The UNT Digital Library
Evidence of Collisional Coherences in the Transport of Hydrogenic Krypton through Amorphous Carbon Foils (open access)

Evidence of Collisional Coherences in the Transport of Hydrogenic Krypton through Amorphous Carbon Foils

We study theoretically and experimentally the population dynamics of the internal state of 60MeV/u Kr35+ ions traversing amorphous carbon foils. A quantum transport theory is developed that incorporates the state mixing induced by the wake field of the ion as well as all the coherences generated by the collisional and radiative redistribution of states. We show that the internal state of the ion is sensitive to collisional coherences and the wake field. The results of the full simulations are found to be in good agreement with experimental data.
Date: August 24, 2001
Creator: Minami, T.
Object Type: Article
System: The UNT Digital Library
Investigation on Stress-Rupture Behavior of a Chopped-Glass-Fiber Composite for Automotive Durability Design Criteria (open access)

Investigation on Stress-Rupture Behavior of a Chopped-Glass-Fiber Composite for Automotive Durability Design Criteria

Practical and inexpensive testing methods were developed to investigate stress-rupture properties of a polymeric composite with chopped glass fiber reinforcement for automotive applications. The material was tested in representative automotive environments to generate experimental data. The results indicate that environments have substantial effects on the stress-rupture behavior. The data were analyzed and developed into stress-rupture design criteria to address one of the durability aspects of the material for automotive structural applications.
Date: August 24, 2001
Creator: Ren, W
Object Type: Report
System: The UNT Digital Library
Ion Temperature Measurements in SSPX (open access)

Ion Temperature Measurements in SSPX

The Ion Doppler Spectrometer instrument on the Sustained Spheromak Physics experiment is described, along with background about it's operation. Results are presented from recent experimental runs, and the data is compared to the results of simple statistical models of heat exchange in two species gasses.
Date: August 24, 2001
Creator: Auerbach, D W; Hill, D N & McLean, H S
Object Type: Report
System: The UNT Digital Library
Learning from the success of MPI. (open access)

Learning from the success of MPI.

The Message Passing Interface (MPI) has been extremely successful as a portable way to program high-performance parallel computers. This success has occurred in spite of the view of many that message passing is difficult and that other approaches, including automatic parallelization and directive-based parallelism, are easier to use. This paper argues that MPI has succeeded because it addresses all of the important issues in providing a parallel programming model.
Date: August 24, 2001
Creator: Gropp, W. D.
Object Type: Article
System: The UNT Digital Library
LLNL PuPS Weld Qualification Plan (open access)

LLNL PuPS Weld Qualification Plan

This plan ensures the quality of the Lawrence Livermore National Laboratory (LLNL) DOE 3013 Standard Plutonium Packaging System (PuPS) can welds meet the requirements stipulated in the DOE Standard 3013-00 ''Stabilization, Packaging, and Storage of Plutonium-Bearing Materials'' (Reference 1) and G-ESR-G-00035, Revision 1 dated July 26, 2000, ''Savannah River Site Stabilization and Packaging Requirements for Plutonium Bearing Materials for Storage.'' (Reference 2) This plan also meets the requirements for a weld qualification plan as stipulated in the G-ESR-G-00035. The Outer Can weld must meet ASME VIII & IX. The Outer Can welds will be evaluated initially and during production. The initial evaluation will be done by performing the following: ASME IX welding procedure qualification, ASME IX operator qualification, and a 25 can Dummy Outer Can (DOC) verification run. During production, product cans and DOCs will be evaluated. Product cans will be evaluated by a combination of visual examination of the weld faces and the use of helium leak checking. The DOCs will be examined by visual examination, leak check, radiographic examination and metallographic examination. Appendix 2 summarizes the requirements of each of these evaluations. The Inner Can weld must meet the leak tightness requirements of DOE 3013. The Inner Can …
Date: August 24, 2001
Creator: Dodson, K E & Riley, D
Object Type: Report
System: The UNT Digital Library
Long Term Oxidation of Model and Engineering TiAl Alloys (open access)

Long Term Oxidation of Model and Engineering TiAl Alloys

The purpose of this research was to characterize the oxidation behavior of several model (TiAl, TiAl-Nb, TiAl-Cr, TiAl-Cr-Nb) and engineering alloys (XD, K5, Alloy 7, WMS) after long-term isothermal exposure ({approx}7000 h) at 704 C, and after shorter time exposure ({approx}1000 h) at 800 C in air. High-resolution field emission and microprobe scanning electron microscopy were used to characterize the scales formed on these alloys. Similarities and differences observed in the scales are correlated with the various ternary and quaternary microalloying additions.
Date: August 24, 2001
Creator: Locci, IE
Object Type: Article
System: The UNT Digital Library
Materials Selection for the HFIR Cold Neutron Source (open access)

Materials Selection for the HFIR Cold Neutron Source

In year 2002 the High Flux Isotope Reactor (HFIR) will be fitted with a source of cold neutrons to upgrade and expand its existing neutron scattering facilities. The in-reactor components of the new source consist of a moderator vessel containing supercritical hydrogen gas moderator at a temperature of 20K and pressure of 15 bar, and a surrounding vacuum vessel. They will be installed in an enlarged beam tube located at the site of the present horizontal beam tube, HB-4; which terminates within the reactor's beryllium reflector. These components must withstand exceptional service conditions. This report describes the reasons and factors underlying the choice of 6061-T6 aluminum alloy for construction of the in-reactor components. The overwhelming considerations are the need to minimize generation of nuclear heat and to remove that heat through the flowing moderator, and to achieve a minimum service life of about 8 years coincident with the replacement schedule for the beryllium reflector. 6061-T6 aluminum alloy offers the best combination of low nuclear heating, high thermal conductivity, good fabricability, compatibility with hydrogen, superior cryogenic properties, and a well-established history of satisfactory performance in nuclear environments. These features are documented herein. An assessment is given of the expected performance of …
Date: August 24, 2001
Creator: Farrell, K.
Object Type: Report
System: The UNT Digital Library
Measured longitudinal beam impedance of booster gradient magnets (open access)

Measured longitudinal beam impedance of booster gradient magnets

The Booster gradient magnets have no vacuum pipe which forces the beam image current to flow along the laminated pole tips. Both D and F style magnets were measured with a stretched wire to determine the longitudinal beam impedance caused by these laminations. Results are compared to calculations done 30 years ago. The inductive part of the magnet impedance is interesting because it partially compensates for the negative inductance effects of space charge on the beam. An R/L circuit consisting of 37K{center_dot} in parallel with between 40 and 100uH is a reasonable approximation to the total impedance of Booster magnet laminations.
Date: August 24, 2001
Creator: Fellenz, James L Crisp and Brian J.
Object Type: Report
System: The UNT Digital Library
A Monte Carlo Approach to Calculate Probability Tables for the Unresolved-Resonance Region Using the AMPX Cross-Section Processing System (open access)

A Monte Carlo Approach to Calculate Probability Tables for the Unresolved-Resonance Region Using the AMPX Cross-Section Processing System

A new module, PURM (Probability tables for the Unresolved Region using Monte Carlo), has been developed for the AMPX-2000 cross-section processing system. PURM uses a Monte Carlo approach to calculate probability tables on an evaluator-defined energy grid in the unresolved-resonance region. For each probability table, PURM samples a Wigner spacing distribution for pairs of resonances surrounding the reference energy. The resonance distribution is sampled for each spin sequence (i.e., {ell}-J pair), and PURM uses the {Delta}{sub 3}-statistics test to determine the number of resonances to sample for each spin sequence. For each resonance, PURM samples the resonance widths from a Chi-square distribution for a specified number of degrees of freedom. Once the resonance parameters are sampled, PURM calculates the total, capture, fission and scatter cross sections at the reference energy using the single-level Breit-Wigner formalism with appropriate treatment for temperature effects. Probability tables have been calculated and compared with NJOY. The probability tables and cross-section values that are calculated by PURM and NJOY are in agreement, and the verification studies with NJOY establish the computational capability for generating probability tables using the new AMPX module PURM.
Date: August 24, 2001
Creator: Dunn, M. E.
Object Type: Article
System: The UNT Digital Library
MULTI-PHASE Cr-BASED ALLOYS FOR AGGRESSIVE HIGH TEMPERATURE ENVIRONMENTS (open access)

MULTI-PHASE Cr-BASED ALLOYS FOR AGGRESSIVE HIGH TEMPERATURE ENVIRONMENTS

Attractive high-temperature mechanical properties and oxidation/hot corrosion resistance have been achieved in a new family of Cr{sub 2}Ta-reinforced Cr alloys. However, inadequate room-temperature toughness remains a key challenge, with the best Cr-Cr{sub 2}Ta alloys exhibiting only modest toughness in the range of 12-14 MPa m{sup 1/2}. The addition of MgO has been shown to significantly improve the room-temperature mechanical properties of unalloyed Cr and was investigated as a means for improving the room-temperature mechanical properties of the Cr-Cr{sub 2}Ta alloys. Microstructural analysis of a series of Cr and Cr-6MgO base alloys was used to investigate the proposed ductilization mechanism of nitrogen gettering by a MgCr{sub 2}O{sub 4} spinel phase, which forms during consolidation of Cr and MgO powders. Nitride and related impurity precipitates have been linked to reduced ductility in Cr at room-temperature. Surprisingly, nitride (and carbide) impurity precipitates were found i n hot-pressed Cr-6 MgO base alloys despite room-temperature tensile ductility of 5%. These precipitates were found adjacent to MgO/MgCr{sub 2}O{sub 4} particles and were somewhat more blunt than those observed in unalloyed Cr. The addition of TiO{sub 2} to unalloyed Cr resulted in similar morphological changes to the nitride and carbide impurity precipitates; however, the TiO{sub 2} dispersed …
Date: August 24, 2001
Creator: Brady, MP
Object Type: Article
System: The UNT Digital Library
Neutron Cross Section Measurements at the Spallation Neutron Source (open access)

Neutron Cross Section Measurements at the Spallation Neutron Source

With the prospect of construction of the Spallation Neutron Source (SNS) at ORNL, and the fantastic high neutron flux, new, up to now impossible, experiments seem to be feasible in the fields of applied nuclear physics and astrophysics. These experiments will supply crucial neutron-induced cross section data for radionuclides, which are badly needed by many applied physics programs. The SNS will be uniquely suited for measuring the cross sections of interest to nuclear criticality safety, accelerator transmutation of nuclear waste (ATW), and heavy element nucleosynthesis for astrophysics. Because the sample sizes required at current facilities are usually too large for practical measurements, scarce information of these cross sections is available. Using the high neutron flux at the SNS will allow these measurements to be made with samples about 40 times smaller than at the next best facility. The large reduction in sample size at the SNS will result in orders of magnitude reduction in background from the radioactive samples and make them much easier to produce; hence, a much wider range of samples will be accessible for measurement at the SNS than at any other facility.
Date: August 24, 2001
Creator: Guber, K. H.
Object Type: Article
System: The UNT Digital Library
Neutron Cross Sections Measurements for Light Elements at ORELA and their Application in Nuclear Criticality (open access)

Neutron Cross Sections Measurements for Light Elements at ORELA and their Application in Nuclear Criticality

The Oak Ridge Electron Linear Accelerator (ORELA) was used to measure neutron total and capture cross sections of aluminium, natural chlorine and silicon in the energy range from 100 eV to {approx}600 keV. ORELA is the only high power white neutron source with excellent time resolution and ideally suited for these experiments still operating in the USA. These measurements were carried out to support the Nuclear Criticality Predictability Program. Concerns about the use of existing cross section data in the nuclear criticality calculations using Monte Carlo codes and benchmarks have been a prime motivator for the new cross section measurements. More accurate nuclear data are not only needed for these calculations but also serve as input parameters for s-process stellar models.
Date: August 24, 2001
Creator: Guber, Klaus H.
Object Type: Article
System: The UNT Digital Library
Nuclear fragmentation cross sections for NASA database development (open access)

Nuclear fragmentation cross sections for NASA database development

Heavy ions with energies of hundreds to thousands of MeV/nucleon are present in the Galactic Cosmic Rays and will be a source of risk to astronaut health when long-duration crewed missions are undertaken. Nuclear interactions of these GCR ions in shielding materials must be accurately modeled by transport codes in order to estimate the dose and dose equivalent at points inside a spacecraft. Uncertainties in the nuclear fragmentation cross sections are propagated into these estimates, and the overall uncertainties increase as shielding depth increases. A program of fragmentation cross section measurements has therefore been undertaken to reduce these uncertainties, using GCR-like ion species and energies in particle accelerators in the United States, at the Brookhaven National Laboratory's Alternating Gradient Synchrotron (AGS) and in Japan at the National Institute of Radiological Science's Heavy Ion Medical Accelerator in Chiba (HIMAC). An extensive set of data has been obtained with beams ranging from helium to iron and including most of the species that are prominent in the GCR.
Date: August 24, 2001
Creator: Zeitlin, Cary J.; Heilbronn, Lawrence H.; Miller, Jack; Fukumura, Akifumi; Iwata, Yoshi; Murakami, Takeshi et al.
Object Type: Article
System: The UNT Digital Library
Nuclear Security: DOE Needs to Improve Control Over Classified Information (open access)

Nuclear Security: DOE Needs to Improve Control Over Classified Information

A letter report issued by the General Accounting Office with an abstract that begins "The Department of Energy (DOE) maintains millions of classified documents containing highly sensitive nuclear weapons design and production information. Allegations that the Peoples Republic of China obtained nuclear warhead designs from an employee of DOE's Los Alamos National Laboratory, as well as the disappearance of two computer hard drives containing highly sensitive weapons information from that same laboratory, have raised concerns about how effectively DOE protects classified information, particularly the most sensitive classified information that is contained in vaults and computer systems. DOE's security program consists of many strategies for protecting and controlling classified information, such as controlling access to classified information through physical and administrative barriers and determining whether a person's work requires a "need to know" the information. DOE has recently increased protection for top-secret documents by revising its Classified Matter Protection and Control Manual, which provides detailed requirements for the protection and control of classified matter. This report reviews the (1) extent to which DOE's Sandia and Los Alamos National Laboratories have implemented DOE's established access controls and need-to-know requirements for classified vaults and computer systems containing the most sensitive classified information as …
Date: August 24, 2001
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Physics and Applications of NIS Junctions (open access)

Physics and Applications of NIS Junctions

This paper reviews the physics and applications of Normal-Insulator-Superconductor (NIS) tunnel junctions. The current-voltage properties of NIS junctions are diode-like with a strong temperature dependence. Hence, these structures can be used as sensitive thermometers at temperatures well below the energy gap, {Delta}, of the superconducting electrode. For junction voltages comparable to {Delta}/q, current flow removes energy from the normal electrode. This property has been exploited to build refrigerators capable of cooling thin-film circuits from 0.3 K to 0.1 K. Calorimeters and bolometers for the detection of X-rays and millimeter-wave radiation, respectively, have successfully been built from NIS junctions. NIS junctions have also been used to probe the superconducting state. Finally, recent ideas for the use of NIS junctions as simple circuit elements are described.
Date: August 24, 2001
Creator: Ullom, J N
Object Type: Article
System: The UNT Digital Library
Prescription Drugs: Importation for Personal Use (open access)

Prescription Drugs: Importation for Personal Use

None
Date: August 24, 2001
Creator: Vogt, Donna U. & Randall, Blanchard, IV
Object Type: Report
System: The UNT Digital Library
Proceedings of Riken BNL Research Center Workshop, Riken Winter School, Quarks, Hadrons and Nuclei-QCD Hard Processes and the Nucleon Spin. Volume 35. (open access)

Proceedings of Riken BNL Research Center Workshop, Riken Winter School, Quarks, Hadrons and Nuclei-QCD Hard Processes and the Nucleon Spin. Volume 35.

None
Date: August 24, 2001
Creator: Saito, N.; Shibata, T. A. & Yazaki, K.
Object Type: Report
System: The UNT Digital Library