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Emission Characteristics of Tantalum, Tungsten, Rhenium, and Iridium in Plasma Diodes

Description: Experimental determinations of the ionic and electronic emission characteristics of Ta, W, Re, and lr cathodes in vapor thermionic converters are compared. It is shown that Ta provides superior thermal ionization qualities at high pressure compared with W, Re, and Lr. High electronic current densities may be obtained from Cs on Re and Cs on Ir at much lower Cs vapor pressures than from Ta or W. An over-all efficiency of 19% was achieved with a Re cathode at 2440 deg K. (auth)
Date: March 15, 1962
Creator: Gust, W. H.
Partner: UNT Libraries Government Documents Department
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Low temperature, sulfur tolerant homogeneous catalysts for the water-gas shift reaction

Description: The purpose of this report is to update and reorganize our recent review on homogeneous catalysis of the water-gas shift reaction (WGSR) based on recent literature publications and patents. This updated version will serve as a means of selecting 10 candidate catalyst systems for use in developing effective, sulfur-tolerant, low temperature WGSR catalysts. This report discusses the variations possible in the basic chemistry associated with WGSR catalytic cycles, including basic, acidic, and neut… more
Date: January 20, 1986
Creator: Laine, R. M.
Partner: UNT Libraries Government Documents Department
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Pu-238 fuel form activities, January 1-31, 1981

Description: This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.
Date: February 1, 1981
Partner: UNT Libraries Government Documents Department
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/sup 238/Pu fuel-form processes. Quarterly report, October-December 1981

Description: Progress in the Savannah River /sup 238/Pu Fuel Form Program is summarized. Work during this period concentrated on the extensive cracking of the /sup 238/PuO/sub 2/ fuel form prior to encapsulation in the iridium containment shell for heat sources. This cracking results in increased recycle cost and decreased production efficiency. To better understand this cracking, Savannah River Laboratory (SRL) has made an extensive review of the development of /sup 238/PuO/sub 2/ fuel forms from small-sca… more
Date: May 1, 1982
Partner: UNT Libraries Government Documents Department
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Ir/PuO/sub 2/ compatibility: transfer of impurities from plutonium dioxide to iridium metal during high temperature aging

Description: Plutonium oxide fuel pellets for powering radioisotopic thermoelectric generators for NASA space vehicles are encapsulated in iridium which has been grain-boundary-stabilized with thorium and aluminum. After aging for 6 months at 1310/sup 0/C under vacuum, enhanced grain growth is observed in the near-surface grains of the iridium next to the PuO/sub 2/. Examination of the grain boundaries by AES and SIMS shows a depletion of thorium and aluminum. Iron, chromium, and nickel from the fuel were f… more
Date: January 1, 1984
Creator: Taylor, D. H.; Christie, W. H. & Pavone, D.
Partner: UNT Libraries Government Documents Department
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Flight-systems safety program. Progress report, February 1982

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Coordination and Special Projects of the US Department of Energy by los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues. Published reference of the results cited in this report should not be made without the explicit permission of the person in charge of th… more
Date: February 1, 1982
Creator: Bronisz, S. E.
Partner: UNT Libraries Government Documents Department
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Pu-238 fuel form activities, January 1-31, 1982

Description: This monthly report for /sup 238/Pu fuel form activities has two main sections: SRP-PuFF facility and SRL fuel form activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.
Date: March 1, 1982
Partner: UNT Libraries Government Documents Department
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Pu-238 fuel form activities, June 1-30, 1980

Description: This monthly report for Pu-238 Fuel Form Activities has two main sections: SRP-PuFF Pu-238 Fuel Form Production Processes and SRL Pu-238 Fuel Form Research and Development. The program status, budget information, and milestone information are discussed in each main section. The Work Breakdown Structures (WBS) for this program is outlined. Only one monthly report per year is processed for EDB.
Date: July 18, 1980
Partner: UNT Libraries Government Documents Department
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The Radiochemistry of Iridium

Description: The general and analytical chemistry of Ir are reviewed and applications to the radiochemistry of Ir are discussed. Topics covered include dissolution of samples containing Ir, counting techniques for radioactive Ir isotopes, radiochemical procedures for Ir radionuclides, and safety practices. A list is included of the radioactive nuclides of Ir. 106 references. (C.H.)
Date: October 1961
Creator: Leddicotte, G. W.
Partner: UNT Libraries Government Documents Department
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Quality engineering and control. Semiannual progress report, November-December 1978, January-April 1979. [PCB]

Description: This document reports the following: atomic absorption spectroscopy of Ir in Pu-Ir alloys; removal of Pu from soil; surface microanalysis using elemental x-ray mapping; microscopic scanning of Ga in Pu; microscopy of defects in Pu; emission spectroscopy of Ir and Y in PuO/sub 2/; gas chromatograhy of PCB's in transformer oils and water; liquid chromatography of chlorophenoxy acid herbicides in water; solution analysis by spark source mass spectrometry; a portable gas sampling system; flamm… more
Date: August 2, 1980
Creator: Carpenter, R. L.
Partner: UNT Libraries Government Documents Department
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Versatile electrochemical microsensors for environmental monitoring

Description: The fabrication of novel multielement microelectrode array sensors is reported. With regard to individual array elements, two main concepts are pursued. One involves the use of relatively non-selective microelectrode elements, coupled with pattern recognition methods, for data analysis. This strategy is most applicable when prior knowledge about the chemical environment is limited, or when mainly qualitative information is sought. The second concept involves the development of arrays containing… more
Date: October 1, 1991
Creator: Glass, R.S.; Hong, K.C. (Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science Dept.); Ashley, K. (San Jose State Univ., CA (United States). Dept. of Chemistry) & Granstaff, V.E. (Sandia National Labs., Albuquerque, NM (United States))
Partner: UNT Libraries Government Documents Department
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Flight-Systems Safety Program, April 1982. Progress report

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Coordination and Special Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues. Published reference of the results cited in this report should not be made without the explicit permission of the person in charge of th… more
Date: July 1, 1982
Creator: Bronisz, S. E.
Partner: UNT Libraries Government Documents Department
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Consumable arc-melting, extruding, and rolling process for iridium sheet

Description: An iridium alloy has been used as cladding for the /sup 238/PuO/sub 2/ fuel in radioisotope thermoelectric generators (RTGs) for recent interplanetary spacecraft such as Voyagers 1 and 2 and will be used for the Galileo and Ulysses spacecraft. The iridium alloy sheet for the fuel cladding used on these missions was fabricated by hot and cold rolling of arc-melted and drop-cast 0.5-kg ingots. Upon completion of production for these spacecraft, an opportunity was taken to conduct process improvem… more
Date: June 1, 1986
Creator: Heestand, R. L.; Copeland, G. L. & Martin, M. M.
Partner: UNT Libraries Government Documents Department
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Space nuclear safety program. Progress report, October-December 1984

Description: This quarterly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Special Nuclear Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed are ongoing; the results and conclusions described may change as the work progresses.
Date: May 1, 1986
Creator: George, T.G. (comp.)
Partner: UNT Libraries Government Documents Department
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Iridium abundance measurements across bio-event horizons in the fossil record

Description: Geochemical measurements have been performed on thousands of rock samples collected across bio-event horizons using Instrumental Neutron Activation Analysis (INAA) for about 40 common and trace elements and radiochemical isolation procedures for Ir. On selected samples, Os, Pt and Au were also radiochemically determined. These studies have encompassed the time interval from the Precambrian-Cambrian transition to the Late Eocene impact (microspherule) horizons. Our early work strengthened the Al… more
Date: January 1, 1989
Creator: Orth, C.J.; Attrep, M. Jr. & Quintana, L.R. (Los Alamos National Lab., NM (USA))
Partner: UNT Libraries Government Documents Department
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Experiments with powdered CMN thermometers between 10 mK and 4K, and a comparison with an NBS SRM 768 fixed-point device

Description: Comparison of a powdered CMN thermometer with an NBS fixed point device demonstrates an internal inconsistency in the T/sub c/'s assigned to the fixed point device. T/sub c/'s between 100 and 200 mK are in excellent agreement with a temperature scale interpolated between He vapor pressure temperatures and nuclear orientation temperatures, but there is a discrepancy of 8% at the 15 mK point. Evidence for different susceptibility-temperature relations for superficially similar CMN thermometers is… more
Date: August 1, 1981
Creator: Fogle, W. E.; Hornung, E. W.; Mayberry, M. C. & Phillips, N. E.
Partner: UNT Libraries Government Documents Department
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Pu-238 fuel form activities, January 1-31, 1983

Description: This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.
Date: March 1, 1983
Partner: UNT Libraries Government Documents Department
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High-temperature compatibility study of iridium (DOP-26 alloy) with graphite and plutonia

Description: This report outlines the materials compatibility tests conducted on DOP-26 iridium alloy and carbon. The carbon used was in the form of woven graphite as present in the impact shell used to encase plutonia in nuclear heat sources. In addition, compatibility tests of the DOP-26 alloy with plutonia are described. The reactivity observed in both systems is discussed. 4 refs., 6 figs.
Date: December 1, 1987
Creator: Axler, K.M. & Eash, D.T.
Partner: UNT Libraries Government Documents Department
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Geochemical anomalies near the Eocene-Oligocene and Permian-Triassic boundaries

Description: Evidence is presented to support the theory that several mass extinctions, i.e., those that define the Permian-Triassic boundary, the Cretaceous-Tertiary boundary, and the Eocene-1 Oligocene boundary, were caused by impact on the earth of extraterrestrial objects having the composition of carbonaceous chondrites and diameters of about 10 km. The evidence consists of anomalously high concentrations of iridium and other siderophile elements at the stratigraphic levels defining the extinctions. (A… more
Date: October 1, 1981
Creator: Asaro, F.; Alvarez, L.W.; Alvarez, W. & Michel, H.V.
Partner: UNT Libraries Government Documents Department
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Performance of oblique angle of incidence collection systems in the VUV

Description: High rejection filters are difficult enough to achieve in the UV-VIS-IR with known materials and constants. Even more difficult is the design and manufacture of rejection filters in the EUV and VUV given the uncertainty of optical constants and their wide variation over this spectral range. We have begun work to characterize materials from 584 A to 1300 A to verify reported optical constants, in order to design and realize the optimum collection system. 8 refs., 2 figs., 8 tabs.
Date: January 1, 1986
Creator: Keller, G.L.; Scott, M.L. & Mitchell, K.
Partner: UNT Libraries Government Documents Department
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