Thoriated-tungsten, split-ring, hollow-cathode electrode for discharge devices

A discharge device having opposite ends and comprising:

• a) a hollow, electrically-insulated elongated element whose interior serves as a discharge chamber and confines a discharge plasma;
• b) a pair of cylindrical electrodes, each electrode located at a different end of said discharge chamber and comprising thoriated tungsten with an alloy composition of tungsten (W) and from about 2% to about 3% of thorium dioxide ThO2, each of said electrodes having a tip and a base, said tip comprising a groove in its outermost edge and having at least one slot also in the outer portion;
• c) a pair of metallic spacers, each spacer being I-shaped in cross-section and being attached to the base of a respective one of said cylindrical electrodes;
• d) a plurality of members each having the means for enclosing a vacuum and each having first and second flange surfaces, at least one of said members having its interior surface respectively attached to a respective one of said I-shaped spacers;
• and
• e) a pair of optical windows, each window being attached to an opposite end of said discharge device.

An electrode assembly for use in a discharge device comprising:

• a) an electrode member comprising thoriated tungsten with an alloy composition of tungsten (W) and from about 2% to about 3% of thorium dioxide ThO2, said electrode having a tip and a base, said tip having a groove in its outermost edge and also at least one slot in its outermost edge;
• b) a copper spacer that is I-shaped in cross-section attached to said base of said electrode member;
• and
• c) a sealing member having means for enclosing a vacuum attached to said I-shaped spacer.