Spin structures of Fe/Gd and Fe/Cr multilayers determined by polarized neutron reflectometry (open access)

Spin structures of Fe/Gd and Fe/Cr multilayers determined by polarized neutron reflectometry

Polarized neutron reflection was used to determine the magnetic structure of two different antiferromagnetically coupled multilayer systems, Fe/Gd and Fe/Cr. In Fe/Gd, the Fe and Gd moments are coupled antiparallel at the interface. At low temperatures a surface induced magnetic phase transition was found. In Fe/Cr, annealing at temperatures of up to 425{degrees}C, resulted in the degrading of antiferromagnetic coupling between Fe layers and in the formation of ferromagnetically coupled regions.
Date: August 1, 1992
Creator: Loewenhaupt, M.; Hahn, W. (Forschungszentrum Juelich GmbH (Germany). Inst. fuer Festkoerperforschung); Huang, Y. Y.; Felcher, G. P. (Argonne National Lab., IL (United States)) & Parkin, S. S. P. (IBM Research Div., San Jose, CA (United States). Almaden Research Center)
Object Type: Article
System: The UNT Digital Library
D2PC sensitivity analysis (open access)

D2PC sensitivity analysis

The Chemical Hazard Prediction Model (D2PC) developed by the US Army will play a critical role in the Chemical Stockpile Emergency Preparedness Program by predicting chemical agent transport and dispersion through the atmosphere after an accidental release. To aid in the analysis of the output calculated by D2PC, this sensitivity analysis was conducted to provide information on model response to a variety of input parameters. The sensitivity analysis focused on six accidental release scenarios involving chemical agents VX, GB, and HD (sulfur mustard). Two categories, corresponding to conservative most likely and worst case meteorological conditions, provided the reference for standard input values. D2PC displayed a wide variety of sensitivity to the various input parameters. The model displayed the greatest overall sensitivity to wind speed, mixing height, and breathing rate. For other input parameters, sensitivity was mixed but generally lower. Sensitivity varied not only with parameter, but also over the range of values input for a single parameter. This information on model response can provide useful data for interpreting D2PC output.
Date: August 1, 1992
Creator: Lombardi, D. P.
Object Type: Report
System: The UNT Digital Library
Electronic excited states as a probe of surface adsorbate structure and dynamics in liquid xenon (open access)

Electronic excited states as a probe of surface adsorbate structure and dynamics in liquid xenon

A combination of second harmonic generation (SHG) and a simple dipole-dipole interaction model is presented as a new technique for determining adsorbate geometries on surfaces. The polarization dependence of SHG is used to define possible geometries of the adsorbate about the surface normal. Absorption band shifts using geometry constraints imposed by SHG data are derived for a dimer constructed from two arbitrarily placed monomers on the surface using the dipole-dipole interaction potential. These formulae can be used to determine the orientation of the two monomers relative to each other. A simplified version of this formalism is used to interpret absorption band shifts for rhodamine B adsorbed on fused silica. A brief history of the exciton is given with particular detail to Xe. Data are presented for transient absorption at RT in liquid xenon on the picosecond time scale. These are observations of both tunneling through the barrier that separates the free and trapped exciton states and the subsequent trapping of the exciton. In high densities both of these processes are found to occur within 2 to 6 picoseconds in agreement with theories of Kmiecik and Schreiber and of Martin. A threshold density is observed that separates relaxation via single binary …
Date: August 1, 1992
Creator: Peterson, E. S.
Object Type: Report
System: The UNT Digital Library
Resolution of safety issues associated with the storage of high-level radioactive waste at the Hanford Site (open access)

Resolution of safety issues associated with the storage of high-level radioactive waste at the Hanford Site

A number of high-level radioactive waste (HLW) safety issues have been identified at the Hanford Site in southeastern Washington State. Resolution of these issues is one of the Highest Priorities of the US Department of Energy. The most urgent issues are the potential for explosions in certain tanks (due to periodic venting of large quantities of flammable gases, or the presence of substantial quantities of ferrocyanide and/or organic compounds in combination with nitrates-nitrites). Other safety issues have been identified as well, such as the requirement for periodic water additions to one tank to control its temperature and the release of noxious vapors from a number of tanks. Substantial progress has been made toward safety issue resolution. Potential mechanisms have been identified for the generation, retention and periodic venting of flammable gas mixtures; potential methods for controlling the periodic release behavior have been identified and in-tank testing will be initiated in 1992. Research is being conducted to determine the initiation temperatures, energetics, reaction sequences and effects of catalysts and initiators on ferrocyanide-nitrate/nitrite reactions; waste characterization on a tank-by-tank basis will be required to identify whether ferrocyanide-containing wastes are safe to store as-is or will require further treatment to eliminate safety concerns. …
Date: August 1, 1992
Creator: Mellinger, G. B. (Pacific Northwest Lab., Richland, WA (United States)) & Tseng, J. C. (USDOE Assistant Secretary for Environmental Restoration and Waste Management, Washington, DC (United States))
Object Type: Article
System: The UNT Digital Library
C RE-SLC: Database for conservation and renewable energy activities (open access)

C RE-SLC: Database for conservation and renewable energy activities

The Western Area Power Administration (Western) requires all its long-term power customers to implement programs that promote the conservation of electric energy or facilitate the use of renewable energy resources. The hope is that these measures could significantly reduce the amount of environmental damage associated with electricity production. As part of preparing the environmental impact statement for Western's Electric Power Marketing Program, Argonne National Laboratory constructed a database of the conservation and renewable energy activities in which Western's Salt Lake City customers are involved. The database provides information on types of conservation and renewable energy activities and allows for comparisons of activities being conducted at different utilities in the Salt Lake City region. Sorting the database allows Western's Salt Lake City customers to be classified so the various activities offered by different classes of utilities can be identified; for example, comparisons can be made between municipal utilities and cooperatives or between large and small customers. The information included in the database was collected from customer planning documents in the files of Western's Salt Lake City office.
Date: August 1, 1992
Creator: Cavallo, J. D.; Tompkins, M. M. & Fisher, A. G.
Object Type: Report
System: The UNT Digital Library
Measurement of current density fluctuations and ambipolar particle flux due to magnetic fluctuations in MST (open access)

Measurement of current density fluctuations and ambipolar particle flux due to magnetic fluctuations in MST

Studies of magnetic fluctuation induced particle transport on Reversed Field Pinch plasmas were done on the Madison Symmetric Torus. Plasma current density and current density fluctuations were measured using a multi-coil magnetic probes. The low frequency (f<50 kHz) current density fluctuations are consistent with the global resistive tearing instabilities predicted by 3-D MHD simulations. At frequencies above 50 kHz, the magnetic fluctuations were detected to be localized with a radial correlation length of about 1--2 cm. These modes are locally resonant modes since the measured dominant mode number spectra match the local safety factor q. The net charged particle flux induced by magnetic fluctuations was obtained by measuring the correlation term <{tilde j}{sub {parallel}} {tilde B}{sub r}>. The result of zero net charged particle loss was obtained, meaning the flux is ambipolar. The ambipolarity of low frequency global tearing modes is satisfied through the phase relations determined by tearing instabilities. The ambipolarity of high frequency localized modes could be partially explained by the simple model of Waltz based on the radial average of small scale turbulence.
Date: August 1, 1992
Creator: Shen, Weimin.
Object Type: Report
System: The UNT Digital Library
User's Guide for the NREL Force and Loads Analysis Program. [National Renewable Energy Laboratory (NREL)] (open access)

User's Guide for the NREL Force and Loads Analysis Program. [National Renewable Energy Laboratory (NREL)]

The following report gives the reader an overview of and instructions on the proper use of the National Renewable Energy Laboratory Force and Loads Analysis Program (FLAP, version 2.2). It is intended as a tool for prediction of rotor and blade loads and response for two- or three-bladed rigid hub wind turbines. The effects of turbulence are accounted for. The objectives of the report are to give an overview of the code and also show the methods of data input and correct code execution steps in order to model an example two-bladed rigid hub turbine. A large portion of the discussion (Sections 6.0, 7.0, and 8.0) is devoted to the subject of inputting and running the code for wind turbulence effects. The ability to include turbulent wind effects is perhaps the biggest change in the code since the release of FLAP version 2.01 in 1988. This report is intended to be a user's guide. It does not contain a theoretical discussion on equations of motion, assumptions, underlying theory, etc. It is intended to be used in conjunction with Wright, Buhl, and Thresher (1988).
Date: August 1, 1992
Creator: Wright, A. D.
Object Type: Report
System: The UNT Digital Library
Frontiers of accelerator instrumentation (open access)

Frontiers of accelerator instrumentation

New technology has permitted significant performance improvements of established instrumentation techniques including beam position and profile monitoring. Fundamentally new profile monitor strategies are required for the next generation of accelerators, especially linear colliders (LC). Beams in these machines may be three orders of magnitude smaller than typical beams in present colliders. In this paper we review both the present performance levels achieved by conventional systems and present some new ideas for future colliders.
Date: August 1, 1992
Creator: Ross, M.
Object Type: Article
System: The UNT Digital Library
A valiant little terminal: A VLT user's manual (open access)

A valiant little terminal: A VLT user's manual

VLT came to be used at SLAC (Stanford Linear Accelerator Center), because SLAC wanted to assess the Amiga's usefulness as a color graphics terminal and T{sub E}X workstation. Before the project could really begin, the people at SLAC needed a terminal emulator which could successfully talk to the IBM 3081 (now the IBM ES9000-580) and all the VAXes on the site. Moreover, it had to compete in quality with the Ann Arbor Ambassador GXL terminals which were already in use at the laboratory. Unfortunately, at the time there was no commercial program which fit the bill. Luckily, Willy Langeveld had been independently hacking up a public domain VT100 emulator written by Dave Wecker et al. and the result, VLT, suited SLAC's purpose. Over the years, as the program was debugged and rewritten, the original code disappeared, so that now, in the present version of VLT, none of the original VT100 code remains.
Date: August 1, 1992
Creator: Weinstein, A.
Object Type: Report
System: The UNT Digital Library
Well, hydrology, and geochemistry problems encountered in ATES systems and their solutions (open access)

Well, hydrology, and geochemistry problems encountered in ATES systems and their solutions

In aquifer thermal energy storage (ATES) systems, wells provide the interface between the energy storage and use. Efficient operational wells are, therefore, essential for the system to run at maximum (design) efficiency. Adequate test drilling to accurately predict aquifer properties is essential in the design phase; proper construction and development are crucial; and proper monitoring of performance is necessary to identify the early stages of clogging and to evaluate the adequacy of well rehabilitation. Problems related to hydrology, well, and aquifer properties include: loss of permeability resulting from gas exsolution, chemical precipitation, and dispersion and movement of fine-grained particles; loss of recoverable heat caused by excessive regional ground-water gradient, hydrodynamic mixing of injected and native ground water, buoyancy flow and heat conduction through the cap and base of the storage zone; leakage up along the well casing; and fracturing'' of a shallow upper aquiclude as a result of an injection pressure greater than the hydrostatic pressure on the aquiclude. The predominant geochemical problems encountered are precipitation of carbonates in some areas and iron plus manganese oxides in others. These precipitation problems can be anticipated, and thus avoided, via geochemical calculations. The likelihood of iron carbonate precipitation is less certain because …
Date: August 1, 1992
Creator: Jenne, E. A. (Pacific Northwest Lab., Richland, WA (United States)); Andersson, O. (VBB VIAK AB, Malmo (Sweden)) & Willemsen, A. (IF Technology, Arnhem, (Netherlands))
Object Type: Article
System: The UNT Digital Library
(National Institute for Petroleum and Energy Research) monthly progress report for June 1992 (open access)

(National Institute for Petroleum and Energy Research) monthly progress report for June 1992

Accomplishments for this period are described briefly under tasks for: Energy Production Research; Fuels Research; and Supplemental Government Program. Energy Production Research includes: reservoir assessment and characterization; TORIS research support; development of improved microbial flooding methods; surfactant flooding methods; development of improved alkaline flooding methods; mobility control and sweep improvement in chemical flooding; gas flood performance prediction improvement; mobility control, profile modification, and sweep improvement in gas flooding; three-phase relative permeability research; thermal processes for light oil recovery; thermal processes for heavy oil recovery; and imaging techniques applied to the study of fluid in porous media. Fuels research includes; development of analytical methodology for analysis of heavy crudes; and thermochemistry and thermophysical properties of organic nitrogen- and diheteroatom-containing compounds. Supplemental Government Program includes: microbial-enhanced waterflooding field project; feasibility study of heavy oil recovery in the midcontinent region--Oklahoma, Kansas, and Missouri; surfactant-enhanced alkaline flooding field project; development of methods for mapping distribution of clays in petroleum reservoirs; summary of geological and production characteristics of class 1, unstructured, deltaic reservoirs; third international reservoir characterization technical conference; process-engineering property measurements on heavy petroleum components; development and application of petroleum production technologies; upgrade BPO crude oil data base; simulation analysis of steam-foam projects; and …
Date: August 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
(National Institute for Petroleum and Energy Research) quarterly technical report, April 1--June 30, 1992 (open access)

(National Institute for Petroleum and Energy Research) quarterly technical report, April 1--June 30, 1992

Progress reports are presented for the following two tasks: development of analytical methodology for analysis of heavy crudes; and thermochemistry and thermophysical properties of organic nitrogen- and diheteroatom-containing compounds. Objectives for task one are: to identify compounds or classes of compounds with significant positive or negative effects on crude oil and/or product properties and characteristics and to develop methods for their determination in conventional or low grade petroleum and syncrudes. Specific objectives for FY92 are: to determine catalytic cracking behavior of individual compound classes in petroleum; and to further develop GC/MS methodology for speciation of nitrogen and sulfur compound in petroleum. Objective for task two is to provide, interpret, and correlate with molecular structure and polarity of molecules, precise and accurate values of thermodynamic properties of organic nitrogen and diheteroatom-containing compounds that occur in or are readily derivable from heavy petroleum and oil shale. The results will enable the prediction of chemical equilibria for conceptual as well as current processes.(AT)
Date: August 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Measurements of carbon dioxide in the Southern Ocean along the WOCE S-4 section (open access)

Measurements of carbon dioxide in the Southern Ocean along the WOCE S-4 section

During the fist year of this two-year grant, we have completed the data acquisition phase at sea along the WOCE-S4 section located along 67{degree}S between 73{degree}W and 172{degree}E in the Pacific sector of the Southern Ocean. The expedition was carried out aboard the Russian Research Ship Akademik IOFFE'' in the period February 14 through April 6, 1992. The total CO{sub 2} concentration and pCO{sub 2} in a total of about 1290 water samples were determined using a coulometer for total CO{sub 2} and an equilibrator/gas chromatograph system for pCO{sub 2}. Surface water samples were analyzed at all the 112 hydrographic stations occupied. Complete or partial profiles were obtained at 58 stations. In addition, a total of 172 determinations were made at sea for 62 bottles of the Standard Reference Solution.
Date: August 1, 1992
Creator: Chipman, D. W.; Rubin, S. I. & Takahashi, T.
Object Type: Report
System: The UNT Digital Library
Ground-water contribution to dose from past Hanford Operations (open access)

Ground-water contribution to dose from past Hanford Operations

The Hanford Environmental Dose Reconstruction (HEDR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides migrating in ground water on the Hanford Site could have reached the public have been identified: (1) through contaminated ground water migrating to the Columbia River; (2) through wells on or adjacent to the Hanford Site; (3) through wells next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ground-water pathway,'' which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated.
Date: August 1, 1992
Creator: Freshley, M. D. & Thorne, P. D.
Object Type: Report
System: The UNT Digital Library
A review of the saturation induced harmonics in the 80 mm aperture RHIC arc dipole magnets (open access)

A review of the saturation induced harmonics in the 80 mm aperture RHIC arc dipole magnets

In this note we shall review, at times with a sense of history, the measured and computed saturation induced harmonics in the cross section of all long and short 80 mm aperture RHIC dipole magnets built so far. With the help of several iterations in the yoke cross section, we have been able to reduce the saturation induced b{sub 2} and b{sub 4} harmonics by more than an order of magnitude. We shall briefly describe those iterations. The calculations described in this note have generally been done with the computer program POISSON. However, while comparing the calculations and measurements, we have included the results of field calculations with the code PE2D and MDP as well. The measurements are the average of up and down ramps. A small difference between the calculations and measurements has been observed consistently in the saturation induced b{sub 2} and b{sub 4} harmonics in all magnets DRA001 through DRA009. More work is still needed to explain the current dependence of skew quadrupole harmonic ({alpha}{sub 1}). We refer to current dependence of harmonics loosely as the saturation induced harmonics; but in an actual magnet it includes other effects like the harmonics induced by the coil deformation due …
Date: August 1, 1992
Creator: Gupta, R.; Thompson, P. & Wanderer, P.
Object Type: Report
System: The UNT Digital Library
Designing reliability into accelerators (open access)

Designing reliability into accelerators

For the next generation of high performance, high average luminosity colliders, the factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis.
Date: August 1, 1992
Creator: Hutton, A.
Object Type: Article
System: The UNT Digital Library
Results of field verification tests in the Tight Mesaverde Group: Piceance Basin, Colorado (open access)

Results of field verification tests in the Tight Mesaverde Group: Piceance Basin, Colorado

The Piceance Basin of western Colorado contains a major potential natural gas resource in Mesaverde blanket and lenticular low permeability gas sands. The basin has been a pilot study area for government sponsored tight gas sand research for over 20 years. This work culminated in the Multiwell Experiment (MWX), a field laboratory consisting of three closely spaced wells, designed by the Department of Energy to study the reservoir and production characteristics of the low permeability sands of the Mesaverde Group in the Rulison Field near Rifle, Colorado. The purpose of this study is to compare geologic, production and reservoir characteristics of the existing Mesaverde producing areas in the Piceance Basin with those same characteristics at the Multiwell site. This study has been performed in two sequential parts, Phase I and Phase II. In Phase I the geologic, production and reservoir engineering parameters were developed for the existing Mesaverde gas producing areas through analysis of log suites, well completion information and production histories. The southern part of the basin was partitioned into three areas having similar geologic and production characteristics. Phase II consisted of field verification tests with cooperative industry partners in which new subsurface geologic and production information was collected …
Date: August 1, 1992
Creator: Kukal, G. C.; Price, E. H.; Hill, R. E. & Monson, E. R.
Object Type: Report
System: The UNT Digital Library
Design of the Nb[sub 3]Sn dipole D20 (open access)

Design of the Nb[sub 3]Sn dipole D20

The design of a 50 mm bore superconducting Nb[sub 3]Sn dipole with a short sample field of 13 T at 4.3 K and a current of 5500 A/turn is presented. The magnet is composed by two double pancake layers. The inner cable has 37 strands with a strand diameter of 0.75 mm and a Cu/Sc ratio of 0.4; the outer cable has 47 strands with a diameter of 0.48 mm and a Cu/Sc ratio of 1.15. In order to obtain a high transfer function and low saturation effects on the multipoles, the stainless steel collar is elliptical and the iron yoke is close-in.'' The thin collar itself provides only a minimum prestress and the full prestress of 100 MPa is given by a 25 mm welded stainless steel shell or by winding a wire around the yoke. Aluminum spacers are used as assembly tools and as a means to control the gap size in the vertically split iron yoke. This paper presents the magnetic design and the calculated stress and strain distribution in structure and coils. A 1 m model called D20 is to be built and tested at LBL.
Date: August 1, 1992
Creator: Dell'Orco, D.; Scanlan, R. & Taylor, C. E.
Object Type: Article
System: The UNT Digital Library
Preliminary lightning tests: Optical fiber penetration of an exclusion region barrier (open access)

Preliminary lightning tests: Optical fiber penetration of an exclusion region barrier

As part of the Direct Optical Initiation (DOI) program, an assessment of the possibility of introducing lightning energy into an exclusion region via an Optical Barrier Feedthrough (OBF) is being carried out. One postulated penetration mechanism is the tracking of current past the OBF on the surface of the dielectric optical fiber itself. During September and October of 1991, a series of tests was conducted on a closed metallic cylindrical test object representing the electrical exclusion region of a weapon. Median-level (30-kA) and severe (200-kA) simulated lightning return strokes, singly, doubly, and in combination with a moderate continuing current, were attached directly to the exterior portion of a fiber optic cable, which penetrated through a hole of controlled size into the interior of the exclusion region. The thickness of the barrier surrounding the hole was 0.06 in. Attempts were made to measure any conducted current flowing on the fiber at distances of 1 and 4 inches from the interior surface of the stainless steel top of the cylinder. Test parameter variations included diameter of the penetration hole (475 and 500 microns), length of the exterior portion of the cable and whether or not its jacket was present, and the applied …
Date: August 1, 1992
Creator: Dinallo, M. A. (Quatro Corp., Albuquerque, NM (United States)) & Fisher, R. J. (Sandia National Labs., Albuquerque, NM (United States))
Object Type: Report
System: The UNT Digital Library
NREL photovoltaic subcontract reports: Abstracts and document control information, 1 August 1991--31 July 1992 (open access)

NREL photovoltaic subcontract reports: Abstracts and document control information, 1 August 1991--31 July 1992

This report contains document control information and abstracts for the National Renewable Energy Laboratory (NREL) subcontracted photovoltaic program publications. It also lists source information on additional publications that describe US Department of Energy (DOE) PV research activities. It is not totally exhaustive, so it lists NREL contacts for requesting further information on the DOE and NREL PV programs. This report covers the period from August 1, 1991, through July 31, 1992. The purpose of continuing this type of publication is to help people keep abreast of specific PV interests, while maintaining a balance on the costs to the PV program. The information in this report is organized under PV technology areas: Amorphous silicon research; polycrystalline thin films (including copper indium diselenide, cadmium telluride, and thin-film silicon); crystalline materials and advanced concepts (including silicon, gallium arsenide, and other group III-V materials); and PV manufacturing technology development (which may include manufacturing information for various types of PV materials).
Date: August 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Nuclear transparency and double beta decay of molybdenum 100 (open access)

Nuclear transparency and double beta decay of molybdenum 100

Data taking is now complete on a double beta decay experiment which has been carried out with collaborators from the Lawrence Berkeley Laboratory, the University of New Mexico, and the Idaho National Engineering Laboratory, and work is continuing on a second collaborative experiment, AGS experiment 850 at the Brookhaven National Laboratory to study nuclear color transparency. In March, the experimental apparatus used to search for double beta decay in molybdenum 100 in the Consil silver mine in Osburn, Idaho was dismantled, and the data analysis is in its final stages. No evidence has been seen for the O{sup +} {yields} O{sup +} mode of zero neutrino double beta decay collaborators with a 1{sigma} lifetime limit of 3 {times} 10{sup 22} years. This limit is 7.5 times greater than the limit we published previously in Physical Review Letters in 1989. Backgrounds have been simulated and fits are currently underway to a simulated O{sup +} {yields} 2{sup +} mode of zero neutrino double beta decay to improve on a very preliminary 1{sigma} lifetime limit of 2.3 {times} 10{sup 21} years presented at the April, 1992 meeting of the APS in Washington. A scintillating fiber detector with three Hamamatsu, H4140, 256 channel multianode …
Date: August 1, 1992
Creator: Nicholson, H. W.
Object Type: Report
System: The UNT Digital Library
Intense beams at the micron level for the Next Linear Collider (open access)

Intense beams at the micron level for the Next Linear Collider

High brightness beams with sub-micron dimensions are needed to produce a high luminosity for electron-positron collisions in the Next Linear Collider (NLC). To generate these small beam sizes, a large number of issues dealing with intense beams have to be resolved. Over the past few years many have been successfully addressed but most need experimental verification. Some of these issues are beam dynamics, emittance control, instrumentation, collimation, and beam-beam interactions. Recently, the Stanford Linear Collider (SLC) has proven the viability of linear collider technology and is an excellent test facility for future linear collider studies.
Date: August 1, 1991
Creator: Seeman, J. T.
Object Type: Article
System: The UNT Digital Library
Design of high-T[sub c] superconducting bolometers for a far infrared imaging array (open access)

Design of high-T[sub c] superconducting bolometers for a far infrared imaging array

The design of high-[Tc] superconducting bolometers for use in a far infrared imaging array from wavelengths 30--100[mu]m is discussed. Measurements of the voltage noise in thin films of YBa[sub 2]CU[sub 3]O[sub 7-[var sigma]] on yttria-stabilized zirconia buffer layers on silicon substrates are used to make performance estimates. Useful opportunities exist for imaging and spectroscopy with bolometer arrays made on micro-machined silicon membranes. A circuit on each pixel which performs some signal integration can improve the sensitivity of large two-dimensional arrays of bolometers which use multiplexed readout amplifiers.
Date: August 1, 1992
Creator: Verghese, S.; Richards, P. L.; Fork, D. K.; Char, K. & Geballe, T. H.
Object Type: Article
System: The UNT Digital Library
Methodology to identify risk-significant components for inservice inspection and testing (open access)

Methodology to identify risk-significant components for inservice inspection and testing

Periodic inspection and testing of vital system components should be performed to ensure the safe and reliable operation of Department of Energy (DOE) nuclear processing facilities. Probabilistic techniques may be used to help identify and rank components by their relative risk. A risk-based ranking would allow varied DOE sites to implement inspection and testing programs in an effective and cost-efficient manner. This report describes a methodology that can be used to rank components, while addressing multiple risk issues.
Date: August 1, 1992
Creator: Anderson, M. T.; Hartley, R. S.; Jones, J. L. Jr.; Kido, C. & Phillips, J. H.
Object Type: Report
System: The UNT Digital Library