Long-Life Miniature Reservoir Cathode For High-Frequency Amplifiers

The proposal describes a low-risk program for solving the remaining problems on reservoir cathodes. The solution will allow production of a miniature cathode with at least 20 Amps/cm2 loading and a life greater than 50,000 hours. All dispenser cathodes are limited by their supply of barium. Reservoir cathodes are unique in that they provide, in principle, unlimited amounts of barium. All other attempts to improve performance do so by conserving existing barium by lowering temperature. Lowering temperature implies a fundamental materials breakthrough that has not been forthcoming. But the remaining problems on reservoir cathodes are largely engineering and fabrication issues. Hence the reservoir cathode is a low-risk solution to the present cathode impasse. The performance of linear beam amplifiers is now acutely limited by cathode technology - both their size and output. Power frequency and life would increase if better cathodes were available. Ion engine performance is limited for the same reasons.