Impregnated cathode
AssigneeHitachi, Ltd.
InventorsSadanori Taguchi, Toshiyuki Aida, Shigehiko Yamamoto, Yukio Honda
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Abstract
An impregnated cathode comprises a porous refractory substrate of refractory material such as tungsten containing at least one of scandium oxide particles and oxide particles containing scandium such as (Al, Sc).sub.2 O.sub.3, and an electron emissive material impregnated into pores of the substrate, and has an operating temperature lower by about 300.degree. C. than that of the conventional impregnated cathode containing no scandium oxide particles, or scandium.
Claims16
An impregnated cathode which comprises a porous refractory substrate and an electron emissive material impregnated into pores in the pourous substrate, wherein said pourous refractory substrate includes at least one of scandium oxide particles and oxide particles containing scandium.
A process for preparing an impregnated cathode which comprises sintering a mixture of at least one metal selected from the group consisting of tungsten, molybdenum, tantalum and rhenium, and at least one of scandium oxide and oxide particles containing scandium, to thereby form a heat-resistant, porous substrate;
- and impregnating an electron emissive material into pores of the porous substrate.
Dependencies are inferred from the claim text.