Accession Number : ADD016508

Title :   Thoriated-Tungsten, Split-Ring, Hollow-Cathode Electrode for Discharge Devices.

Descriptive Note : Patent, Filed 14 Mar 94, patented 27 Sep 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Seibert, Edward J ; Ferguson, Gerald D ; Taylor, Marie E

Report Date : 27 Sep 1994

Pagination or Media Count : 7

Abstract : An electrode assembly for a gas or metal vapor discharge device is disclosed. A pair of electrode assemblies each comprising thoriated tungsten with an alloy composition of tungsten (W) and from about 2% to about 3% of thorium dioxide ThO2 are located at opposite ends of the discharge chamber of the discharge device. The tip of the electrode preferably has four slots equally spaced around its circumference and a groove at its outermost edge. The tip of the electrode provides mechanical flexibility that inhibits the cracking of the thoriated tungsten electrode when it is mounted in the discharge device. Each electrode assembly further comprises a copper spacer, preferably I-shaped in cross-section, brazed against the base of the electrode and against a vacuum flange. The pair of electrode assemblies confines the discharge of the discharge device between the tips of the electrodes and inhibits the arc condition from finding its way to delicate vacuum seals.

Descriptors :   *ELECTRODES, *TUNGSTEN, *PATENTS, *CATHODES, *GAS DISCHARGES, ALLOYS, ASSEMBLY, CHAMBERS, COPPER, CROSS SECTIONS, EDGES, FLANGES, METAL VAPORS, SLOTS, SPACERS, THORIUM DIOXIDE, VACUUM SEALS, OPTICAL PROPERTIES, LIGHT, EXCITATION, ELECTRICAL PROPERTIES, EMISSION

Subject Categories : Physical Chemistry
      Electricity and Magnetism
      Inorganic Chemistry
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE