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A very-low-Q diffractometer for an advanced spallation source (open access)

A very-low-Q diffractometer for an advanced spallation source

Proposals to build new, more powerful spallation sources and the introduction of advanced moderator concepts will result in neutron sources that are 20 times more luminous than the brightest available today. These developments provide opportunity and challenge to expand the capabilities of present low-Q instruments using new designs. A particularly interesting case is the design of an instrument capable of measurements to ``very low`` momentum transfer, say Q {approx} 0.0007 {Angstrom}{sup {minus}1}. We consider an instrument to be built on a 20 Hz, 330 kW target and viewing a coupled liquid-hydrogen moderator. The instrument would use a frame-definition chopper to select a wavelength band suitable for the required Q-domain. Monte Carlo optimization of the geometry was performed by choosing the minimum observable Q always to be 0.0007 {Angstrom}{sup {minus}1} and then maximizing intensity/variance at Q = 0.0020 {Angstrom}{sup {minus}1} while maintaining reasonable constraints. The resulting design is 48 m long, with a maximum wavelength band 16.9 {Angstrom} {le} {lambda} {le} 20.5 {Angstrom}. The Monte Carlo simulations of instrument performance include wavelength-dependent effects from aluminum and fused silica windows, air, chopper opening and closing times and phase jitter, measured spectrum and detector efficiencies, sample transmission and multiple scattering, and gravity. The …
Date: July 1, 1993
Creator: Seeger, P. A. & Hjelm, R. P.
Object Type: Article
System: The UNT Digital Library
Construction of a superconducting RFQ structure (open access)

Construction of a superconducting RFQ structure

This paper reports the design and construction status of a niobium superconducting RFQ operating at 194 MHz. The structure is of the rod and post type, novel in that each of four rods is supported by two posts oriented radially with respect to the beam axis. Although the geometry has four-fold rotation symmetry, the dipole-quadrupole mode splitting is large, giving good mechanical tolerances. The simplicity of the geometry enables designing for good mechanical stability while minimizing tooling costs for fabrication with niobium. Design details of a prototype niobium resonator, results of measurements on room temperature models, and construction status are discussed.
Date: July 1, 1993
Creator: Shepard, K. W.; Kennedy, W. L. & Crandall, K. R.
Object Type: Article
System: The UNT Digital Library
ARIES tokamak reactor study. [Annual] report, 1 December 1992--30 November 1993 (open access)

ARIES tokamak reactor study. [Annual] report, 1 December 1992--30 November 1993

This report examines the feasibility of a standard poloidal diverter design for ARIES- 2/4 with the determination of the peak thermal loading on, and the plasma temperature facing a poloidal double null diverter. The ARIES-2/4 reactors produce 2,141 MW of fusion power of which 1712 MW is contained in the neutron channel. Of the remaining 429 MW of charged particle power, 47 MW is radiated from the core by bremsstrahlung and synchrotron modes to the vessel walls. The remaining 382 MW of charged particle or transport power crosses the core/edge interface. The fact that the bulk of the power is contained in the neutron channel makes the application of a poloidal divertor possible. The ARIES-2/4 diverter constraints for peak heat load and peak particle temperature are set by current technology and materials knowledge. Divertor geometry constraints are imposed by the plasma equilibrium and the 2/4 vacuum vessel. The diverter heat load and plasma temperatures are determined from edge particle and energy balances. These balances are important characteristics of the plasma edge because the transport power from the plasma core must pass through the edge and be deposited on tokamak components. The Braams` B2 code is a multifluid ion and electron …
Date: July 1, 1993
Creator: Steiner, D.
Object Type: Report
System: The UNT Digital Library
Fabrication of neptunium oxide targets for irradiation in FFTF (open access)

Fabrication of neptunium oxide targets for irradiation in FFTF

The feasibility of.fabdcating neptunium oxide into various target configurations for irradiation in FFTF to produce plutonium-238 was demonstrated by the Nuclear Fuels Technology group at Los Alamos. The configurations included cold-pressed and sintered pellets and wafers and powder encapsulated in 0.0025-cm thick molybdenum foil envelopes. NpO{sub 2} Pellets with a density of 86.5%TD and wafers that were approximately 2-cm diameter by 0.0229-cm thick were produced. Uranium dioxide wafers were fabricated without cracking and warping by assuring uniform distribution of powder in the die before pressing and by setting the pressed wafers on ceramic microspheres for sintering. Forming the powder into microspheres before pressing enabled uniform die filling. Radiation exposure measurements made during the NPO{sub 2} processing showed a maximum of 500 g/mo could be handled in the shielded gloveboxes at Los Alamos and still comply with the exposure limits set by DOE Radiological Control Manual, DOE-EH-0256T.
Date: July 1, 1993
Creator: Blair, H. T. & Chidester, K. M.
Object Type: Article
System: The UNT Digital Library
Transient studies of low temperature catalysts for methane conversion. Quarterly technical progress report, January 1, 1993--March 30, 1993 (open access)

Transient studies of low temperature catalysts for methane conversion. Quarterly technical progress report, January 1, 1993--March 30, 1993

This report summarizes studies conducted during the past quarter on the partial oxidation of methane on the following catalysts: vanadium phosphate, unsupported and supported on silica, and on the silica (SiO{sub 2}) support. It was found that the unsupported vanadium phosphate catalyst exhibits some selectivity towards formaldehyde at relatively low methane conversions (up to 5% conversion). The selectivity decreases even further on the silica supported VPO catalyst without a significant increase in conversion. In the case of silica, the reaction temperature decreases, and the formaldehyde selectivity is higher than in the case of the VPO catalyst.
Date: July 1, 1993
Creator: Wolf, E. E.
Object Type: Report
System: The UNT Digital Library
Semi-annual report of the Department of Energy, Office of Environmental Restoration and Waste Management, Quality Assessment Program (open access)

Semi-annual report of the Department of Energy, Office of Environmental Restoration and Waste Management, Quality Assessment Program

This Quality Assessment Program (QAP) is designed to test the quality of the environmental measurements being reported to the Department of Energy by its contractors. Since 1976, real or synthetic environmental samples that have been prepared and thoroughly analyzed at the Environmental Measurements Laboratory (EML) have been distributed at first quarterly and then semi-annually to these contractors. Their results, which are returned to EML within 90 days, are compiled with EML`s results and are reported back to the participating contractors 30 days later. A summary of the reported results is available to the participants 3 days after the reporting deadline via a modem-telephone connection to the EML computer. This report presents the results from the analysis of the 38th set of environmental quality assessment samples (QAP XXXVIII) that were received on or before June 2, 1993.
Date: July 1, 1993
Creator: Sanderson, C. G. & Klusek, C. S.
Object Type: Report
System: The UNT Digital Library
Improving reservoir conformance using gelled polymer systems. Third quarterly report, March 25, 1993--June 24, 1993 (open access)

Improving reservoir conformance using gelled polymer systems. Third quarterly report, March 25, 1993--June 24, 1993

The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems - an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium-based system where polyacrylamide and xanthan are crosslinked by CR(III) and an organic crosslinked system. Development of the KUSP1 system and evaluation and identification of a suitable organic crosslinked system will be done. The laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Accomplishments for this quarter are presented for the following tasks: development and selection of gelled polymer systems; physical and chemical characterization of gel systems; mechanism of in situ gelation; and mathematical …
Date: July 1, 1993
Creator: Green, D. W.; Willhite, G. P.; Buller, C.; McCool, S.; Vossoughi, S. & Michnick, M.
Object Type: Report
System: The UNT Digital Library
Circuit description of unipolar DC-to-DC converters for APS storage ring quadrupoles and sextupoles (open access)

Circuit description of unipolar DC-to-DC converters for APS storage ring quadrupoles and sextupoles

This paper describes the control, interlock, and power circuits for 680 unipolar switch mode DC-to-DC converters used to regulate the Advanced Photon Sources (APS`s) storage ring quadrupole and sextupole magnet currents. Quadrupole current stability is {plus_minus} 6{times}10{sup {minus}5} and the sextupole current stability is {plus_minus}3{times}10{sup {minus}4}. The stability is obtained with pulse width modulation, operating at a switching frequency of 20kHz with full current switching. The converters are housed in 200 cabinets located on top of the storage ring tunnel. Raw DC power is distributed from 80 AC-to-DC power supplies, four at each of 20 locations around the storage ring. Voltages, currents, and temperatures are computer monitored and logged for the converters and magnets. All converters and magnets are water cooled with the flow and pressure monitored at the inlet and outlet of groups. Water is interlocked with the raw power supplies and not the individual converters.
Date: July 1, 1993
Creator: McGhee, D. G.
Object Type: Article
System: The UNT Digital Library
Estimation of maximum temperatures in spallation targets (open access)

Estimation of maximum temperatures in spallation targets

None
Date: July 1, 1993
Creator: Boyack, K. W.; Sherman, M. P. & Kelly, J. E.
Object Type: Report
System: The UNT Digital Library
A digital feedback system for orbit stabilization (open access)

A digital feedback system for orbit stabilization

The authors are reporting on the design and preliminary results of a prototype digital feedback system for the storage rings at the NSLS. The system will use a nonlinear eigenvector decomposition algorithm. It will have a wide dynamic range and will be able to correct noise in the orbit over a bandwidth in excess of 60 Hz. A Motorola-167 CPU board is used to sample the PUE`s at a minimum rate of 200 Hz and an HP-742rt board is used to read the sampled signals and to generate a correction signal for the orbit correctors.
Date: July 1, 1993
Creator: Friedman, A.; Bozoki, E.; Singh, O. & Smith, J.
Object Type: Article
System: The UNT Digital Library
Evaluation of a lighting program for small commercial and industrial buildings in the northeast (open access)

Evaluation of a lighting program for small commercial and industrial buildings in the northeast

An impact evaluation of a commercial lighting retrofit program of COM/Electric is briefly described, together with the methodological development required for the evaluation. The evaluation is conducted for a large sample of buildings (over 1,000 treatment and over 200 control buildings) using whole-building electric billing data. Historic modeling approaches - Annual or Seasonal Aggregate Model, Building Specific Thermal Model (e.g. PRISM), and Pooled Factors Model - are discussed, and an extension of PRISM is presented. The methods presented provide some useful methodological insight, and further work could be conducted to make improvements. The energy savings are evaluated using several methods. Overall, results indicate that adjusted program first-year investment cost ratio, the ratio of total costs to first-year adjusted electricity savings, is about $0.60/kWh. First-year investment cost is greater for larger total investments in buildings than for smaller investments.
Date: July 1, 1993
Creator: MacDonald, M.; Trumble, D. & Farley, J.
Object Type: Article
System: The UNT Digital Library
GENSHELL: A genesis database 2D to 3D shell transformation program (open access)

GENSHELL: A genesis database 2D to 3D shell transformation program

GENSHELL is a three-dimensional shell mesh generation program. The three-dimensional shell mesh is generated by mapping a two-dimensional quadrilateral mesh into three dimensions according to one of several types of transformations: translation, mapping onto a spherical, ellipsoidal, or cylindrical surface, and mapping onto a user-defined spline surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, revolving about an axis, and scaling the coordinates. GENSHELL can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two-dimensional geometries. The code GJOIN is then used to join the separate sections into a single body. GENSHELL updates the EXODUS quality assurance and information records to help track the codes and files used to generate the mesh. GENSHELL reads and writes two-dimensional and three-dimensional mesh databases in the GENESIS database format; therefore, it is compatible with the preprocessing, postprocessing, and analysis codes in the Sandia National Laboratories Engineering Analysis Code Access System (SEACAS).
Date: July 1, 1993
Creator: Sjaardema, G. D.
Object Type: Report
System: The UNT Digital Library
Magnetic measurement facility for the 7-GeV Advanced Photon Source (open access)

Magnetic measurement facility for the 7-GeV Advanced Photon Source

A magnet measurement facility for semi-automatic measurement control and real-time data analysis has been developed to measure more than 1000 magnets for the Advance Photon Source. One dipole and three rotating coil measurement systems and corresponding probe coils are described.
Date: July 1, 1993
Creator: Kim, S. H.; Kim, K.; Doose, C.; Hogrefe, R. & Merl, R.
Object Type: Article
System: The UNT Digital Library
Phase separation and superconductivity in La{sub 2}CuO{sub 4+{delta}}: Effects of oxygen diffusion (open access)

Phase separation and superconductivity in La{sub 2}CuO{sub 4+{delta}}: Effects of oxygen diffusion

In oxygen-annealed La{sub 2}CuO{sub 4+{delta}} ({delta}{approximately}0.03), bulk magnetization measurements show an increase of {approximately}4K in the superconducting T{sub c} when the sample is cooled slowly through a narrow temperature range near 195K. At this temperature, {sup 139}La NQR spectra exhibit a concomitant appearance of an anomalous feature associated with the metallic phase whose spectral weight increases with cooling rate. The data suggests a distribution of local structures and annealing-dependent volume fraction on this part of the sample. Interpretation of these results in terms of oxygen diffusion in a phase separated material is considered and a picture consistent with the observed changes in T{sub c} is obtained. Other possible origins of these anomalies and the role they play in determining the superconducting properties of this system are discussed.
Date: July 1, 1993
Creator: Reyes, A. P.; Hammel, P. C.; Ahrens, E. T.; Thompson, J. D.; Canfield, P. C.; Fisk, Z. et al.
Object Type: Article
System: The UNT Digital Library
Kinetic studies of electrochemical generation of Ag(II) ion and catalytic oxidation of selected organics (open access)

Kinetic studies of electrochemical generation of Ag(II) ion and catalytic oxidation of selected organics

The goal of this research is to develop a method to treat mixed hazardous wastes containing selected organic compounds and heavy metals, including actinide elements. One approach is to destroy the organic via electrochemical oxidation to carbon dioxide, then recover the metal contaminants through normally accepted procedures such as ion exchange, precipitation, etc. The authors have chosen to study the electrochemical oxidation of a simple alcohol, iso-propanol. Much of the recent work reported involved the use of an electron transfer mediator, usually the silver(I)/(II) redox couple. This involved direct electrochemical generation of the mediator at the anode of a divided cell followed by homogeneous reaction of the mediator with the organic compound. In this study the authors have sought to compare the mediated reaction with direct electrochemical oxidation of the organic. In addition to silver(I)/(II) they also looked at the cobalt(II)/(III) redox coupled. In the higher oxidation state both of these metal ions readily hydrolyze in aqueous solution to ultimately form insoluble oxide. The study concluded that in a 6M nitric acid solution at room temperature iso-propanol can be oxidized to carbon dioxide and acetic acid. Acetic acid is a stable intermediate and resists further oxidation. The presence of Co(III) …
Date: July 1, 1993
Creator: Zawodzinski, C.; Smith, W. H. & Martinez, K. R.
Object Type: Report
System: The UNT Digital Library
Radiation measurements during cavities conditioning on APS RF test stand (open access)

Radiation measurements during cavities conditioning on APS RF test stand

In order to determine the shielding structure around the Advanced Photon Source (APS) synchrotron and storage ring RF stations, the X-ray radiation has been measured in the near field and far field regions of the RF cavities during the normal conditioning process. Two cavity types, a prototype 352-MHz single-cell cavity and a 352-MHz five-cell cavity, are used on the APS and are conditioned in the RF test stand. Vacuum measurements are also taken on a prototype 352-MHz single-cell cavity and a 352-MHz five-cell cavity. The data will be compared with data on the five-cell cavities from CERN.
Date: July 1, 1993
Creator: Grudzien, D. M.; Kustom, R. L.; Moe, H. J. & Song, J. J.
Object Type: Article
System: The UNT Digital Library
Magnetic measurements of the storage ring quadrupole magnets for the 7-GeV Advanced Photon Source (open access)

Magnetic measurements of the storage ring quadrupole magnets for the 7-GeV Advanced Photon Source

The pre-production quadrupole magnet for the Advanced Photon Source (APS) storage ring has been used. The multipole coefficients meet the tolerance requirements. The field-gradient integrals are measured relative to a reference quadrupole. By using two laser beam units, the magnetic and geometrical axes of the magnet are aligned within 0.2 mrad. The dependencies of the sextupole coefficient and the magnetic center on the excitation current are corrected by shunting the magnetic potentials of the top and bottom yokes.
Date: July 1, 1993
Creator: Kim, S. H.; Kim, K.; Doose, C.; Hogrefe, R. & Merl, R.
Object Type: Article
System: The UNT Digital Library
A pulsed septum magnet for the APS (open access)

A pulsed septum magnet for the APS

A pulsed septum magnet has been designed and constructed for beam injection and extraction in the Advanced Photon Source at Argonne National Laboratory. The magnets will be similar for the Positron Accumulator Ring (PAR), the Injector Synchrotron, and the Storage Ring. The septum itself is 2 mm thick and consists of 1-mm-thick copper and S1010 steel explosion-bonded together. The PAR magnet is driven by a 1500-Hz, 12-kA half sine wave current pulse. The core is made of 0.36-mm-thick laminations of silicon steel. The nearly uniform interior field is 0.75 T and the exterior field is 0.0004 T at the undisturbed beam position and 0.0014 T at the bumped beam position. Testing of the magnet awaits the completion of the power supply.
Date: July 1, 1993
Creator: Turner, L. R.; McGhee, D. G.; Mills, F. E. & Reeves, S.
Object Type: Article
System: The UNT Digital Library
Material-not-categorized-as-waste survey for 1992 (open access)

Material-not-categorized-as-waste survey for 1992

In October 1992, the US Department of Energy, Richland Field Office (RL) requested that Westinghouse Hanford Company (WHC) respond to a letter from EM-331 asking for completion of a survey of items in storage but not categorized as waste (Roberts 1992). The letter contained an attachment with instructions on how to fill out the attached form and what to exclude from the survey (Appendix A). This report is a summary of the information from the response issued to RL. This report primarily is for use in estimating future waste volumes that may have been overlooked because of the nature of their classification as material not categorized as waste (MNCAW) (i.e., not yet declared Waste).
Date: July 1, 1993
Creator: Jacobsen, P. H.
Object Type: Report
System: The UNT Digital Library
Analysis of superconducting magnetic energy storage applications at a proposed wind farm site near Browning, Montana (open access)

Analysis of superconducting magnetic energy storage applications at a proposed wind farm site near Browning, Montana

A computer program was developed to analyze the viability of integrating superconducting magnetic energy storage (SMES) with proposed wind farm scenarios at a site near Browning, Montana. The program simulated an hour-by-hour account of the charge/discharge history of a SMES unit for a representative wind-speed year. Effects of power output, storage capacity, and power conditioning capability on SMES performance characteristics were analyzed on a seasonal, diurnal, and hourly basis. The SMES unit was assumed to be charged during periods when power output of the wind resource exceeded its average value. Energy was discharged from the SMES unit into the grid during periods of low wind speed to compensate for below-average output of the wind resource. The option of using SMES to provide power continuity for a wind farm supplemented by combustion turbines was also investigated. Levelizing the annual output of large wind energy systems operating in the Blackfeet area of Montana was found to require a storage capacity too large to be economically viable. However, it appears that intermediate-sized SMES economically levelize the wind energy output on a seasonal basis.
Date: July 1, 1993
Creator: Gaustad, K. L. & De Steese, J. G.
Object Type: Article
System: The UNT Digital Library
Curecanti-Blue Mesa-Salida 115-kV transmission lines access roads rehabilitation, maintenance, and construction project. Environmental Assessment (open access)

Curecanti-Blue Mesa-Salida 115-kV transmission lines access roads rehabilitation, maintenance, and construction project. Environmental Assessment

Western Area Power Administration (Western) is a power marketing agency of the US Department of Energy, with jurisdiction in 15 western states. The Salt Lake City Area (SLCA) of Western performs the agency`s mission in parts of Colorado, New Mexico, Texas, Utah, Arizona, Wyoming, and Nevada. As part of its mission, Western owns, operates, and maintains a system of transmission lines for transmitting bulk electrical energy from points of generation to and between delivery points. Part of that system in southwestern Colorado includes the Blue Mesa-Curecanti and Blue Mesa-Salida 115-kV transmission lines. Western proposes to conduct maintenance and improve its access roads for these two transmission lines. This paper discusses the impacts to the existing environment as well as the environmental consequences resulting from the maintenance and construction that is proposed.
Date: July 1, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Investigation of oxygen functional groups in low rank coal (open access)

Investigation of oxygen functional groups in low rank coal

The distribution of the organic oxygen content of coals among the principal oxygen containing functional groups typically is determined by a combination of chemical and spectroscopic methods (1,2) and results in a classification scheme such as % carboxyl, % hydroxyl, % carbonyl, and % ether. A notable subdivision in this classification scheme is the differentiation of phenols in a coal on the basis of their ortho-substitution pattern (3). Apart from this distinction, the further classification of oxygen into functional group subsets is virtually nonexistent. This paper presents initial experiments that indicate a fuller characterization of oxygen distribution in low rank coal is possible. The experimental approach couples selective chemical perturbation and solid state NMR analysis of the material, specifically, the fluorination of Argonne Premium Coal {number_sign}8, North Dakota lignite, and spectroscopic examination by high resolution solid state {sup 19}F NMR (4). The fluorination reagent is diethylaminosulfur trifluoride (DAST), (Et){sub 2}NSF{sub 3}, which promotes a rich slate of oxygen functional group interconversions that introduce fluorine into the coal matrix (5). The virtual absence of this element in coals make {sup 19}F an attractive NMR nuclei for this application (6). The present experiments use direct detection of the {sup 19}F nucleus under …
Date: July 1, 1993
Creator: Hagaman, E. W. & Lee, S. K.
Object Type: Article
System: The UNT Digital Library
Shock compression properties of silicon carbide (open access)

Shock compression properties of silicon carbide

An investigation of the shock compression and release properties of silicon carbide ceramic has been performed. A series of planar impact experiments has been completed in which stationary target discs of ceramic were struck by plates of either similar ceramic or other appropriate material at velocities up to 2.2 km/s with a propellant gun facility. The particle velocity history at the interface between the back of the target ceramic and a lithium-fluoride window material was measured with laser velocity interferometry (VISAR). Impact stresses achieved in these experiments range between about 10 and 50 GPa. Numerical solutions and analytic methods were used to determine the dynamic compression and release stress-strain behavior of the ceramic. Further analysis of the data was performed to determine dynamic strength and compressibility properties of silicon carbide.
Date: July 1, 1993
Creator: Grady, D. E. & Kipp, M. E.
Object Type: Report
System: The UNT Digital Library
Sol-spray preparation, particulate characteristics, and sintering of alumina powders (open access)

Sol-spray preparation, particulate characteristics, and sintering of alumina powders

Fine alumina powders of spherical morphology and narrow particle-size distribution have been synthesized by a technique that uses precipitation/peptization/spray drying of boehmite sol prepared from aluminum nitrate. The spray-dried powder was further washed with solvents of varying polarities, such as acetone, isopropanol, and tert-butanol. This post-spray-drying treatment changed the powder`s particle-size distribution, morphology, density, and compaction characteristics. Microstructure, dielectric properties, and effect of post-treatment on the boehmite-sol-derived alumina powders in reducing agglomeration are discussed.
Date: July 1, 1993
Creator: Varma, H. K.; Mani, T. V.; Damodaran, A. D.; Warrier, K. G. K. & Balachandran, U.
Object Type: Article
System: The UNT Digital Library