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in subjects: "Cathodes"

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INEX simulations of the optical performance of the AFEL

The AFEL (Advanced Free-Electron Laser) Project at Los Alamos National Laboratory is presently under construction. The project's goal is to produce a very high-brightness electron beam which will be generated by a photocathode injector and a 20 MeV rf-linac. Initial laser experiments will be performed with a 1-cm-period permanent magnet wiggler which will generate intense optical radiation near a wavelength of 3.7 {mu}m. Future experiments will operate with slotted-tube'' electromagnetic wiggle… more

Date: January 1, 1991

Creator: Goldstein, J.C.; Wang, T.S.F. & Sheffield, R.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Avalanche transistor pulser for fast-gated operation of micro-channel plate image-intensifiers

Transistors operated in the avalanche mode are employed to generate a 1000 volt 10 to 30 nsec wide pulse with less than 4 nsec rise and fall times. This pulse is resistively attenuated to approximately equal to 270 volts and drives the image intensifier tube which is a load of approximately equal to 200 pf. To reduce stray inductance and capacitance, transistor chips were assembled on a thick-film hybrid substrate. Circuit parameters, operating conditions, and coupling to the microchannel plate… more

Date: January 1, 1977

Creator: Lundy, A.; Parker, J. R.; Lunsford, J. S. & Martin, A. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electrochemical photovoltaic cells. Project 65039 quarterly technical progress report, April 15-July 31, 1980

Liquid-junction photoelectrochemical cells can be used either for the direct conversion of solar energy to electricity or to generate stored chemical species available for later electrochemical discharge. The objectives of this program are to identify experimental approaches for electrochemical photovoltaic cells that not only show promise of high power-conversion efficiencies but also have the potential to achieve long life and the capacity for energy storage. The work is organized as follows:… more

Date: September 1, 1980

Creator: Ang, P. G.P. & Sammells, A. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Determination of optimum electrolyte composition for molten carbonate fuel cells

The objective of this study is to determine the optimum electrolyte composition for molten carbonate fuel cells. To accomplish this, the contractor will provide: (1) Comprehensive reports of on-going efforts to optimize carbonate composition. (2) A list of characteristics affected by electrolyte composition variations (e.g. ionic conductivity, vapor pressure, melting range, gas solubility, exchange current densities on NiO, corrosion and cathode dissolution effects). (3) Assessment of the overa… more

Date: January 1, 1987

Creator: Yuh, C. Y. & Pigeaud, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Design of neutron streak camera for fusion diagnostics

The D-T burn time for advanced laser-fusion targets is calculated to be very short, < 50 ps. We describe the design of a neutron streak camera of 16 ps resolving time that can be used to study the temporal history of fusion burn. The cathode of the neutron streak camera is sensitive to neutrons and is curved such that the difference in the neutron path lengths from a point source to various parts of the cathode is compensated by electron transit times within the streak tube. Thus the cathode ca… more

Date: June 1, 1982

Creator: Wang, C. L.; Kalibjian, R. & Singh, M. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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X-Y spacial distribution experiments with Parmela or, what I did on my summer vacation

Experiments using the Parmela simulation program predict that the potentially uneven spacial distributions in the electron beam generated by laser emission from the photo cathode gun has no appreciable effect on the beam outcome when compared to a the more uniform thermionic gun. 23 figs., 4 tabs.

Date: August 1, 1991

Creator: Houston, J.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Development of improved cathodes for solid oxide fuel cells

The University of Missouri-Rolla conducted a 17 month research program focused on the development and evaluation of improved cathode materials for solid oxide fuel cells (SOFC). The objectives of this program were: (1) the development of cathode materials of improved stability in reducing environments; and (2) the development of cathode materials with improved electrical conductivity. The program was successful in identifying some potential candidate materials: Air sinterable (La,Ca)(Cr,Co)O{su… more

Date: March 1, 1991

Creator: Anderson, H.U.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Proposed uv-FEL user facility at BNL

The NSLS at Brookhaven National Laboratory is proposing the construction of a UV-FEL operating in the wavelength range from visible to 750{Angstrom}. Nano-Coulomb electron pulses will be generated at a laser photo-cathode RF gun at a repetition rate of 10 KHz. The 6 ps pulses will be accelerated to 250 MeV in a superconducting linac. The FEL output will serve four stations with independent wavelength tuning, using two wigglers and two rotating mirror beam switches. Seed radiation for the FEL am… more

Date: January 1, 1991

Creator: Ben-Zvi, Ilan; Di Mauro, L. F.; Krinsky, S.; White, M. G.; Yu, L. H.; Batchelor, K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1979

Activities in a program to develop a Ni/Zn battery for electric vehicle propulsion are reported. Aspects discussed include battery design and development, nickel cathode study, and basic electrochemistry. A number of engineering drawings are supplied. 61 figures, 11 tables. (RWR)

Date: June 1, 1980

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1979

Progress achieved under ANL Contract No. 31-109-38-4248 from 16 August 1978 to 16 August 1979 is reported. The first segment of the overall program, component development, consists of four basic tasks proceeding in parallel: nickel electrode development, zinc electrode development, separator development, and sealed cell development. Each of these tasks is reported herein on a self-contained basis. System engineering is the second major subdivision of the effort. It includes the design and testi… more

Date: June 1, 1980

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Inert Electrodes Program fiscal year 1988 annual report

The Inert Electrodes Program, being conducted by Pacific Northwest Laboratory (PNL), involves improving the Hall-Heroult cells used by the Aluminum Industry for the electrochemical production of aluminum. The PNL research centers on developing more energy efficient, longer-lasting anodes and cathodes and ancillary equipment. Major accomplishments for Fiscal Year 1988 are summarized below. 14 refs., 56 figs., 9 tabs.

Date: October 1, 1989

Creator: Strachan, D.M.; Marschman, S.C.; Davis, N.C.; Friley, J.R. & Schilling, C.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Oxide cathode lifetime improvements at RTNS-II

Results are reported for an ongoing effort to optimize D/sup +/ beam production by the MATS-III ion source used at the RTNS-II. The oxide cathode assembly originally designed for lower power operation has been modified and redesigned for higher electron current yield, longer life and serviceability. A factor of 2.5 has been gained in cathode lifetime due to these changes. The details of the changes and results and benefits in operation and performance are given. In addition, the technique used … more

Date: September 29, 1986

Creator: Massoletti, D.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Determination of optimum electrolyte composition for molten carbonate fuel cells

Date: January 1, 1986

Creator: Pigeaud, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Observation of high-power millimeter wave emission from a virtual cathode

Intense bursts of mm wave power have been observed in microwave generation experiments with a relativistic electron beam (REB) virtual cathode oscillator. In this device an electron beam is injected into a drift space at a current above the space-charge-limit, and a potential develops downstream which is large enough to reflect electrons back to the source region. Two mechanisms can give rise to microwave oscillations in a virtual cathode device: electrons reflexing between the real and virtual… more

Date: January 1, 1985

Creator: Davis, H. A.; Bartsch, R. R.; Sherwood, E. G.; Stringfield, R. M. & Thode, L. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental and theoretical investigation of high gradient acceleration

This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-FG0291ER-40648. Experimental and Theoretical Investigations of High Gradient Acceleration.'' This grant supports three research tasks: Task A consists of the design and fabrication of a 17GHz of photocathode gun, Task B supports the testing of high gradient acceleration using a 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tas… more

Date: February 1, 1992

Creator: Bekefi, G.; Chen, C.; Chen, S.; Danly, B.; Temkin, R.J. & Wurtele, J.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Comparison of cesium iodide and gold photocathodes for x-ray streak cameras

X-ray streak cameras at Lawrence Livermore Laboratory use gold transmission photocathodes for x-ray detection. Other photocathode materials which might provide improved sensitivity without loss of temporal resolution are of interest. Of particular interest are dielectrics such as cesium iodide. Simultaneous measurements of the sensitivity to 500 eV x-rays of both gold and cesium iodide photocathodes in the LLL Soft X-ray Streak Camera were made. Enhanced sensitivity with the Csl photocathodes i… more

Date: January 1, 1979

Creator: Stradling, G.L.; Medecki, H.; Attwood, D.T.; Kauffman, R.L. & Henke, B.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The polarized electron gun for the SLC

A new polarized electron gun for use on the SLC at SLAC has been built and tested. It is a diode gun with a laser driven GaAs photocathode. It is designed to provide short (2ns) pulses of 10 A at 160 kV at 120 Hz. The design features of the gun and results from a testing program on a new and dedicated beam line are presented. Early results from operation on the SLC will also be shown.

Date: March 1, 1992

Creator: Schultz, D. C.; Clendenin, J.; Frisch, J.; Hoyt, E.; Klaisner, L.; Woods, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development of an ion source for long-pulse (30-s) neutral beam injection

This paper describes the development of a long-pulse positive ion source that has been designed to provide high brightness deuterium beams (divergence approx. = 0.25/sup 0/ rms, current density approx. = 0.15 A cm/sup -2/) of 40 to 45 A, at a beam energy of 80 keV, for pulse lengths up to 30 s. The design and construction of the ion source components are described with particular emphasis placed on the long-pulse cathode assembly and ion accelerator.

Date: January 1, 1982

Creator: Menon, M. M.; Barber, G. C.; Blue, C. W.; Dagenhart, W. K.; Gardner, W. L.; Haselton, H. H. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Shuttering Efficiencies of Nanosecond-Gated Photoemissive Shutter Tubes

Recent studies show that effective shuttering of photoemissive tubes, such as Silicon-Intensified-Target Vidicons (SITVs) and Microchannel-plate Image Intensifier Tubes (MCPTs), can vary widely depending upon the extent of their opacity to an input flux of photons. Optical feedthrough signals from photon transmission through the photocathode to the target or phosphor ranging from 10/sup -4/ to 10/sup -9/ (when compared with gated signals) were measured for a large sampling of commercially avail… more

Date: January 1, 1985

Creator: Yates, George J.; Jaramillo, Steven A.; Pagano, Thomas S. & Black, J.Paul

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fuel cell applied research: electrocatalysis and materials. Quarterly report, April 1-June 30, 1979

Topics studied include: (1) oxygen reduction and cyclic voltammetry on carbon supported platinum electrodes in 85% H/sub 3/PO/sub 4/; (2) oxygen reduction on platinum in 85% H/sub 3/PO/sub 4/ with small additions of trifluoromethane sulfonic acid or trifluoracetic acid; (3) overpotential characteristics of electrodes at interfaces with solid oxide electrolytes; and (4) oxygen diffusion through interconvection material in high temperature solid electrolyte fuel cells. Also, studies of phosphoric… more

Date: January 1, 1980

Creator: Srinivasan, S.; Isaacs, H. S.; McBreen, J.; O'Grady, W. E.; Olender, H.; Olmer, L. J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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SPE water electrolysis technology development for large scale hydrogen production. Progress report No. 4, June 15, 1976--September 30, 1976

Porous carbon fiber paper was selected as the cathode membrane and electrode assembly support based on over 1200 hr operational evaluation. Three potential anode supports are under test. All three appear technically satisfactory after 500 to 1200 hr operational evaluation on each. Optimization of molds and molding techniques for a foil backed ribbed carbon collector of bipolar design, including ribbed flow fields, manifolds, ports and sealing surfaces, is in process. Over 2800 hr demonstrated a… more

Date: October 7, 1976

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Improved vacuum surface flashover performance of polymer insulators by the use of unique triple junction designs

Previous research and theories about surface flashover in vacuum indicate that the triple junction region plays a critical role in the insulator flashover process. To attempt to improve upon the performance of the standard 45-degree frustum insulator, three different insulator geometries with modified triple junction regions were investigated. Two samples of each geometry, each 2 cm thick, were tested to obtain the flashover voltage levels in a low 10{sup {minus}5} Torr vacuum using a 1.2-micro… more

Date: January 1, 1991

Creator: Smith, J. D.; Kahaian, D. J.; Honig, E. M.; Montoya, R. E.; Rosocha, L. A.; Allen, G. R. (Los Alamos National Lab., NM (United States)) et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The effects of halides on the performance of coal gas-fueled molten carbonate fuel cells: Final report, October 1986-October 1987

This report presents the results of a program to determine the probable tolerable limits of hydrogen chloride and hydrogen fluoride present in the fuel and oxidant streams of molten carbonate fuel cells that are operating on gasified coal. A literature survey and thermodynamic analyses were performed to determine the likely effects of halides on cell performance and materials. Based on the results of these studies, accelerated corrosion experiments and electrode half-cell performance tests were… more

Date: October 1, 1987

Creator: Magee, T. P.; Kunz, H. R.; Krasij, M. & Cote, H. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Chemical Technology Division, Annual technical report, 1991

Highlights of the Chemical Technology (CMT) Division's activities during 1991 are presented. In this period, CMT conducted research and development in the following areas: (1) electrochemical technology, including advanced batteries and fuel cells; (2) technology for fluidized-bed combustion and coal-fired magnetohydrodynamics; (3) methods for treatment of hazardous and mixed hazardous/radioactive waste; (4) the reaction of nuclear waste glass and spent fuel under conditions expected for an uns… more

Date: March 1, 1992

Item Type: Report

Partner: UNT Libraries Government Documents Department