US 4,288,717 A · Thermionic cathode apparatus

Abstract

A thermionic cathode includes an electron emitting tip, lanthanum hexaboride tip supporting heaters in close contact with both sides of the tip and supporting the tip, and elastic electroconductive members in pressure contact with outer surfaces of the tip supporting heaters for supplying electric current. The tip supporting heaters are obtained by cutting lanthanum hexaboride having high anisotropy due to its layered structure so as to form a pair of parallel planes perpendicular to a pressing direction when hot-pressed, and abrade-polishing the parallel planes. The tip supporting heaters are brought into close contact with the tip and the elastic electroconductive members at the resulting smooth surfaces thereof. The apparatus of the invention has a prolonged lifetime and high efficiency.

Claims3

Dependent claims

A thermionic cathode comprising an electron emitting tip, tip supporting heaters made of a carbonaceous material arranged in contact with both sides of said tip, respectively, and supporting said tip, and elastic electroconductive members fixed to a base, said electroconductive members being arranged in pressure contact with the outer surfaces of said tip supporting heaters, and serving to supply an electric current thereto;

said tip supporting heaters being obtained by cutting said carbonaceous material, said carbonaceous material being obtained by hot-pressing a molding of synthetic resin that does not melt under heating, so as to form a pair of parallel planes perpendicular to the pressing direction, abrasion-polishing said parallel planes and then bringing the resulting smooth surfaces into close contact with said tip and said electroconductive members.

Dependencies are inferred from the claim text.

Thermionic cathode apparatus

Life of this patent

Thermionic cathode apparatus

Life of this patent

Abstract

Claims3