Aluminum hydroxide coating thickness measurements and brushing tests on K West Basin fuel elements (open access)

Aluminum hydroxide coating thickness measurements and brushing tests on K West Basin fuel elements

Aluminum hydroxide coating thicknesses were measured on fuel elements stored in aluminum canisters in K West Basin using specially developed eddy current probes . The results were used to estimate coating inventories for MCO fuel,loading. Brushing tests successfully demonstrated the ability to remove the coating if deemed necessary prior to MCO loading.
Date: September 11, 1998
Creator: Pitner, A. L.
Object Type: Report
System: The UNT Digital Library
Crystal field in the heavy fermion compound CeAl{sub 3}. (open access)

Crystal field in the heavy fermion compound CeAl{sub 3}.

Although the crystal field has a strong influence on the heavy fermion properties of CeAl{sub 3}, the parameters of the crystal field Hamiltonian have not been established. We present the results of an analysis of inelastic neutron scattering data on CeAl{sub 3} to resolve this issue. By combining the neutron scattering results with measurements of the single crystal magnetic susceptibility, we have obtained an unambiguous set of crystal field parameters in CeAl{sub 3}: B{sub 2}{sup 0} = (5.8 {+-} 0.2) x 10{sup {minus}2} meV and B{sub 4}{sup 0} = (2.3 {+-} 0.1) x 10{sup {minus}2} meV. The corresponding level scheme of the ground multiplet of the Ce{sup 3+} ion is characterized by a {Lambda}{sub 9} {vert_bar} {+-} 3/2> ground state doublet and two close-lying excited doublets {Lambda}{sub 8} {vert_bar} {+-} 5/2> and {Lambda}{sub 7} {vert_bar} {+-} 1/2> at an energy of {approximately} 6.4 meV at 20 K. A comparison of the crystal field parameters along the RAl{sub 3} (R = Ce, Pr and Nd) series of isostructural compounds shows that in CeAl{sub 3}, A{sub 2}{sup 0} <r{sup 2}> is an order of magnitude larger, and A{sub 4}{sup 0} <R{sup 4}> is three times larger, than in PrAl{sub 3} and NdAl{sub …
Date: September 11, 1998
Creator: Goremychkin, E. A.
Object Type: Article
System: The UNT Digital Library
Implementation of improved interactive image analysis at the Advanced Photon Source (APC) linac. (open access)

Implementation of improved interactive image analysis at the Advanced Photon Source (APC) linac.

An image-analysis system, based on commercially available data visualization software (IDL [1]), allows convenient interaction with image data while still providing calculated beam parameters at a rate of up to 2 Hz. Image data are transferred from the IOC to the workstation via EPICS [2] channel access. A custom EPICS record was created in order to overcome the channel access limit of 16k bytes per array. The user can conveniently calibrate optical transition radiation (OTR) and fluorescent screens, capture background images, acquire and average a series of images, and specify several other filtering and viewing options. The images can be saved in either IDL format or APS-standard format (SDDS [3]), allowing for rapid postprocessing of image data by numerous other software tools.
Date: September 11, 1998
Creator: Arnold, N.
Object Type: Article
System: The UNT Digital Library
A high peak power S-band switching system for the Advanced Photon Source (APS) Linear Accelerator (Linac). (open access)

A high peak power S-band switching system for the Advanced Photon Source (APS) Linear Accelerator (Linac).

An S-band linear accelerator is the source of particles and front end of the Advanced Photon Source [1] injector. Additionally, it will be used to support a low-energy undulator test line (LEUTL) and to drive a free-electron laser (FEL). To provide maximum linac availability for all uses, an additional modulator-klystron subsystem has been built,and a waveguide-switching and distribution subsystem is now under construction. The combined subsystems provide a hot spare for any of the five S-band transmitters that power the lina cand have been given the additional function of powering an rf gun test stand whenever they are not otherwise needed. Design considerations for the waveguide-switching subsystem, topology selection, timing, control, and system protection provisions are described.
Date: September 11, 1998
Creator: Grelick, A. E.
Object Type: Article
System: The UNT Digital Library
Highlights of modern nuclear structure. (open access)

Highlights of modern nuclear structure.

Excitations of nuclei close to magic {sup 132}Sn have been investigated by analysis of fission product {gamma}-ray data measured at Eurogam II using a {sup 248}Cm source. Results for the N=82 isotopes up to {sup 136}Xe, for the one proton-one neutron nucleus {sup 134}Sb, and for the N=84 isotones {sup 134}Sn. {sup 135}Sb, and {sup 136}Te are summarized. The interpretation of the observed level spectra is mainly based on shell model calculations using empirical proton-proton interactions from {sup 134}Te, neutron-neutron interactions from is {sup 134}Sn, and proton-neutron interactions estimated (with scaling as A{sup {minus}1/3}) from the well-known {sup 210}Bi spectrum.
Date: September 11, 1998
Creator: Daly, P. J.
Object Type: Article
System: The UNT Digital Library
Deep x-ray lithography fabrication of mm Wave cavities at the Advanced Photon Source. (open access)

Deep x-ray lithography fabrication of mm Wave cavities at the Advanced Photon Source.

Millimeter-wave (mmWave) accelerating cavity structures have been manufactured using the deep x-ray lithography (DXRL) technique. These cavity structures have potential applications as parts of linear accelerators, microwave undulatory, and mm-wave amplifiers. The microfabrication process includes manufacturing of precision x-ray masks, exposure of positive resist by x-rays through the mask, resist development, and electroforming of the final microstructure. Prototypes of a 32-cell, 108-GHz constant-impedance cavity and a 66-cell, 94-GHz constant-gradient cavity were fabricated at APS. Using an HP8510C 26-GHz vector network analyzer, rf measurements are being prepared with a frequency up- and down-converter before and after a test cavity structure. Preliminary design parameters for a 91-GHz multi-module klystron along with an overview of the DXRL technology are also discussed.
Date: September 11, 1998
Creator: Song, J. J.
Object Type: Article
System: The UNT Digital Library
High power test results of the first SRRC/ANL high current L-band RF gun. (open access)

High power test results of the first SRRC/ANL high current L-band RF gun.

A joint program is underway between the SRRC (Synchrotrons Radiation Research Center, Taiwan) and ANL (Argonne National Laboratory, USA) for developing a high current L-band photocathode rf guns. We have constructed an L-Band (1.3 Ghz), single cell rf photocathode gun and conducted low power tests at SRRC. High power rf conditioning of the cavity has been completed at ANL. In this paper we report on the construction and high power test results. So far we have been able to achieve > 120 MV/m axial electric field with minimal dark current. This gun will be used to replace the AWA (Argonne Wakefield Accelerator)[l] high current gun.
Date: September 11, 1998
Creator: Ho, C. H.
Object Type: Article
System: The UNT Digital Library
Theories of electromagnetic productions of pions. (open access)

Theories of electromagnetic productions of pions.

The current theoretical approaches for investigating the {gamma}N {r_arrow} {pi}N and N(e,e{prime}{pi}) reactions are reviewed. It is shown that the dynamical approach can be used to test the predictions from hadron structure calculations. Some N* form factors calculated from using various chiral constituent quark models are presented.
Date: September 11, 1998
Creator: Lee, T. S. H.
Object Type: Article
System: The UNT Digital Library
Estimates of Refrigerator Loads in Public Housing Based on Metered Consumption Data (open access)

Estimates of Refrigerator Loads in Public Housing Based on Metered Consumption Data

The New York Power Authority (NYPA), the New York City Housing Authority (NYCHA), and the U.S. Departments of Housing and Urban Development (HUD) and Energy (DOE) have joined in a project to replace refrigerators in New York City public housing with new, highly energy-efficient models. This project laid the ground work for the Consortium for Energy Efficiency (CEE) and DOE to enable housing authorities throughout the United States to bulk-purchase energy-efficient appliances. DOE helped develop and plan the program through the ENERGY STAR@ Partnerships program conducted by its Pacific Nofiwest National Laboratory (PNNL). PNNL was subsequently asked to conduct the savings evahations for 1996 and 1997. PNNL designed the metering protocol and occupant survey, supplied and calibrated the metering equipment, and managed and analyzed the data. The 1996 metering study of refrigerator energy usage in New York City public housing (Pratt and Miller 1997) established the need and justification for a regression-model-based approach to an energy savings estimate. The need originated in logistical difficulties associated with sampling the population and pen?orming a stratified analysis. Commonly, refrigerators[a) with high representation in the popula- tion were missed in the sampling schedule, leaving significant holes in the sample and difficulties for the stratified …
Date: September 11, 1998
Creator: Miller, JD & Pratt, RG
Object Type: Report
System: The UNT Digital Library
Flywheel energy storage advances using HTS bearings. (open access)

Flywheel energy storage advances using HTS bearings.

High-Temperature-Superconducting (HT) bearings have the potential to reduce idling losses and make flywheel energy storage economical. Demonstration of large, high-speed flywheels is key to market penetration. Toward this goal, a flywheel system has been developed and tested with 5-kg to 15-kg disk-shaped rotors. Rlm speeds exceeded 400 mls and stored energies were >80 W-hr. Test implementation required technological advances in nearly all aspects of the flywheel system. Features and limitations of the design and tests are discussed, especially those related to achieving additional energy storage.
Date: September 11, 1998
Creator: Mulcahy, T. M.
Object Type: Article
System: The UNT Digital Library
The US Department of Energy`s prime contractor fees on subcontractor costs (open access)

The US Department of Energy`s prime contractor fees on subcontractor costs

In Fiscal Year 1996, the Department`s prime contractors awarded $5.3 billion in subcontracts. The purpose of this audit was to determine if the Department adjusted the fee bases of prime contractors to reflect the actual effort necessary to manage the technical and administrative activities of their subcontractors.
Date: September 11, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Structure-Based Predictive Model for Coal Char Combustion (open access)

Structure-Based Predictive Model for Coal Char Combustion

Progress was made this period on a number of tasks. A significant advance was made in the incorporation of macrostructural ideas into high temperature combustion models. Work at OSU by R. Essenhigh in collaboration with the University of Stuttgart has led to a theory that the zone I / II transition in char combustion lies within the range of conditions of interest for pulverized char combustion. The group has presented evidence that some combustion data, previously interpreted with zone II models, in fact takes place in the transition from zone II to zone 1. This idea was used at Brown to make modifications to the CBK model (a char kinetics package specially designed for carbon burnout prediction, currently used by a number of research and furnace modeling groups in academia and industry). The resulting new model version, CBK8, shows improved ability to predict extinction behavior in the late stages of combustion, especially for particles with low ash content. The full development and release of CBK8, along with detailed descriptions of the role of the zone 1/2 transition will be reported on in subsequent reports. ABB-CE is currently implementing CBK7 into a special version of the CFD code Fluent for use …
Date: September 11, 1998
Creator: Hadad, Christopher M.; Calo, Joseph M.; Essenhigh, Robert H. & Hurt, Robert H.
Object Type: Report
System: The UNT Digital Library
Experimental measurements of hydrodynamic instabilities on NOVA of relevance to astrophysics (open access)

Experimental measurements of hydrodynamic instabilities on NOVA of relevance to astrophysics

Large lasers such as Nova allow the possibility of achieving regimes of high energy densities in plasmas of millimeter spatial scales and nanosecond time scales. In those plasmas where thermal conductivity and viscosity do not play a significant role, the hydrodynamic evolution is suitable for benchmarking hydrodynamics modeling in astrophysical codes. Several experiments on Nova examine hydrodynamically unstable interfaces. A typical Nova experiment uses a gold millimeter-scale hohlraum to convert the laser energy to a 200 eV blackbody source lasting about a nanosecond. The x-rays ablate a planar target, generating a series of shocks and accelerating the target. The evolving area1 density is diagnosed by time-resolved radiography, using a second x-ray source. Data from several experiments are presented and diagnostic techniques are discussed.
Date: September 11, 1998
Creator: Budil, K. S.; Cherfils, C.; Drake, R. P.; Farley, D.; Glendinning, S. G.; Kalantar, D. H. et al.
Object Type: Article
System: The UNT Digital Library
Estimation of Damage Preference From Strike Parameters (open access)

Estimation of Damage Preference From Strike Parameters

Estimation of an opponent's damage preference is illustrated by discussing the sensitivity of stability indices and strike parameters to it and inverting the results to study the sensitivity of estimates to uncertainties in strikes. Costs and stability indices do not generally have the monotonicity and sensitivity needed to support accurate estimation. First and second strikes do. Second strikes also have proportionality, although they are not unambiguously interpretable. First strikes are observable and have the greatest overall power for estimation, whether linear or numerical solutions are used.
Date: September 11, 1998
Creator: Canavan, G. H.
Object Type: Report
System: The UNT Digital Library
Data sieving and collective I/O in ROMIO. (open access)

Data sieving and collective I/O in ROMIO.

The I/O access patterns of parallel programs often consist of accesses to a large number of small, noncontiguous pieces of data. If an application's I/O needs are met by making many small, distinct I/O requests, however, the I/O performance degrades drastically. To avoid this problem, MPI-IO allows users to access a noncontiguous data set with a single I/O function call. This feature provides MPI-IO implementations an opportunity to optimize data access. We describe how our MPI-IO implementation, ROMIO, delivers high performance in the presence of noncontiguous requests. We explain in detail the two key optimizations ROMIO performs: data sieving for noncontiguous requests from one process and collective I/O for noncontiguous requests from multiple processes. We describe how one can implement these optimizations portably on multiple machines and file systems, control their memory requirements, and also achieve high performance. We demonstrate the performance and portability with performance results for three applications--an astrophysics-application template (DIST3D), the NAS BTIO benchmark, and an unstructured code (UNSTRUC)--on five different parallel machines: HP Exemplar, IBM SP, Intel Paragon, NEC SX-4, and SGI Origin2000.
Date: September 11, 1998
Creator: Thakur, R.; Gropp, W. & Lusk, E.
Object Type: Article
System: The UNT Digital Library
Operation of the APS rf gun. (open access)

Operation of the APS rf gun.

The Advanced Photon Source (APS) has a thermionic-cathode rf gun system capable of providing beam to the APS linac. The gun system consists of a 1.6-cell thermionic-cathode rf gun, a fast kicker for beam current control, and an alpha magnet for bunch compression and injection into the APS linac line. This system is intended for use both as an injector for positron creation, and as a first beam source for the Low-Energy Undulator Test Line (LEUTL) project [1]. The first measured performance characteristics of the gun are presented.
Date: September 11, 1998
Creator: Lewellen, J. W.
Object Type: Article
System: The UNT Digital Library
An inelastic neutron scattering study of the spin dynamics of Yb{sub 1-x}Lu{sub x}Al{sub 3}. (open access)

An inelastic neutron scattering study of the spin dynamics of Yb{sub 1-x}Lu{sub x}Al{sub 3}.

We present the results of a systematic inelastic neutron scattering study of the spin dynamics of the mixed valent compound YbAl{sub 3} doped with nonmagnetic lutetium. The aim of the investigation is to clarify the origin of the unusual gap-like magnetic response observed in YbAl{sub 3}, which can be modeled by two inelastic peaks: a narrow peak at 34 meV with HWHM, r = 6.4 {+-} 0.8 meV and a broad peak at 44 meV with {Lambda} = 30 {+-} 1 meV. Lutetium substitution leads to a substantial increase in the linewidth ({Lambda} = 9 {+-} 1 meV at x = 0.1) and a decrease in the intensity (down by 60% at x = 0.1) of the narrow component, with a negligible effect on the broad inelastic peak. This trend is confirmed with higher doping resulting in the complete suppression of the narrow peak at x {ge} 0.35. The results indicate that the narrow component arises from coherent excitation processes within the hybridized 4f-band, which are destroyed by disorder, while the broad component is not so sensitive to the loss of coherence.
Date: September 11, 1998
Creator: Osborn, R.
Object Type: Article
System: The UNT Digital Library
Annealing and mechanical properties of bulk Y-Ba-Cu-O. (open access)

Annealing and mechanical properties of bulk Y-Ba-Cu-O.

Single-domain melt-processed YBa{sub 2}Cu{sub 3}O{sub x}/Y{sub 2}BaCuO{sub 5} and conventional polycrystalline sintered YBa{sub 2}Cu{sub 3}O{sub x} pellets were prepared. Elastic modulus, hardness, and fracture strength were measured on selected sections cut from the pellets. Strength in the melt-processed pellets ranged from 32 to 94 MPa and was highest in the center. Variations in strength were related to microstructural features, especially Y{sub 2}BaCuO{sub 5} distribution. To improve strength, we attempted to minimize microcracking by manipulating cooling rates, annealing times, and oxygen partial pressure. Extent of cracking was evaluated by electron microscopy and change in elastic modulus and strength. We found that control of annealing reduced microcracking of the polycrystalline sintered pellets, but had little effect on the single-domain melt-processed pellets.
Date: September 11, 1998
Creator: Goretta, K. C.
Object Type: Article
System: The UNT Digital Library
Supporting R&D of industrial fuel cell developers. (open access)

Supporting R&D of industrial fuel cell developers.

Argonne National Laboratory is supporting the industrial developers of molten carbonate fuel cells (MCFCs) and tubular solid oxide fuel cells (SOFCs). The results suggest that a lithium concentration level of 65-75 mol% in the LiNa electrolyte will improve cell performance. They have made inroads in understanding the interfacial resistance of bipolar plate materials, and they have reduced the air electrode overpotential in OSFCs by adding dopants.
Date: September 11, 1998
Creator: Krumpelt, M.
Object Type: Article
System: The UNT Digital Library
Gravimeter using high-temperature superconductor bearing. (open access)

Gravimeter using high-temperature superconductor bearing.

We have developed a sensitive gravimeter concept that uses an extremely low-friction bearing based on a permanent magnet (PM) levitated over a high-temperature superconductor (HTS). A mass is attached to the PM by means of a cantilevered beam, and the combination of PM and HTS forms a bearing platform that has low resistance to rotational motion but high resistance to horizontal, vertical, or tilting motion. The combination acts as a low-loss torsional pendulum that can be operated in any orientation. Gravity acts on the cantilevered beam and attached mass, accelerating them. Variations in gravity can be detected by time-of-flight acceleration, or by a control coil or electrode that would keep the mass stationary. Calculations suggest that the HTS gravimeter would be as sensitive as present-day superconducting gravimeters that need cooling to liquid helium temperatures, but the HTS gravimeter needs cooling only to liquid nitrogen temperatures.
Date: September 11, 1998
Creator: Hull, J. R.
Object Type: Article
System: The UNT Digital Library
Non-destructive assay of EBR-II blanket elements using resonance transmission analysis. (open access)

Non-destructive assay of EBR-II blanket elements using resonance transmission analysis.

Resonance transmission analysis utilizing a faltered reactor beam was examined as a means of determining the {sup 239}Pu content in Experimental Breeder Reactor-II depleted uranium blanket elements. The technique uses cadmium and gadolinium falters along with a {sup 239}Pu fission chamber to isolate the 0.3 eV resonance in {sup 239}Pu. In the energy range of this resonance (0.1 eV to 0.5 ev), the total microscopic cross-section of {sup 239}Pu is significantly greater than the cross-sections of {sup 238}U and {sup 235}U. This large difference allows small changes in the {sup 239}Pu content of a sample to result in large changes in the mass signal response. Tests with small stacks of depleted uranium and {sup 239}Pu foils indicate a significant change in response based on the {sup 239}Pu content of the foil stack. In addition, the tests indicate good agreement between the measured and predicted values of {sup 239}Pu up to approximately two weight percent.
Date: September 11, 1998
Creator: Klann, R.T. & Poenitz, W.P.
Object Type: Report
System: The UNT Digital Library
Production of negative hydrogen and deuterium ions in microwave-driven ion sources. (open access)

Production of negative hydrogen and deuterium ions in microwave-driven ion sources.

The authors report progress they have made in the production of negative hydrogen and deuterium atomic ions in magnetically-confined microwave-driven (2.45 GHz) ion sources. The influence of source surface material, microwave power, source gas pressure and magnetic field configuration on the resulting ion current is discussed. Results strongly suggest that, at least in the source, vibrationally excited molecular hydrogen, the precursor to atomic negative ion production, is produced via a surface mechanism suggested by Hall et al. rather than via a gas phase reaction as is generally believed to be the case in most ion sources.
Date: September 11, 1998
Creator: Spence, D.
Object Type: Article
System: The UNT Digital Library
The design of an accelerator for advanced pulse radiolysis experiments. (open access)

The design of an accelerator for advanced pulse radiolysis experiments.

New accelerator techniques have made it possible to make shorter and shorter electron pulses. If appropriate detection techniques are available, these pulses make it possible to measure many important sub-picosecond chemical processes. We are proposing an accelerator system that can be used to measure important sub-picosecond chemical processes, such as solvation, vibrational relaxation, excited state relaxations and molecular fragmentation.
Date: September 11, 1998
Creator: Jonah, C. D.
Object Type: Article
System: The UNT Digital Library
Study of the {Delta} structure and N{Delta} interactions with N(e,e'{pi}) and d(e,e'{pi}) reactions. (open access)

Study of the {Delta} structure and N{Delta} interactions with N(e,e'{pi}) and d(e,e'{pi}) reactions.

A dynamical approach for using the {gamma}N {r_arrow} {pi}N and N(e,e{prime}{pi}) reactions to test the chiral constituent quark model is reviewed. Recent results for the {Delta} excitations and predictions for future experiments are presented. It is shown that the polarization observables of d(e,e{prime}{pi}) reactions are useful for investigating the N{Delta} interactions which are crucial in exploring the {Delta} components in nuclei and the properties of {Delta}-rich systems created in relativistic heavy-ion collisions.
Date: September 11, 1998
Creator: Lee, T. S. H.
Object Type: Article
System: The UNT Digital Library