Patent · US Expired

Indirectly heated dispenser metal capillary cathode for electrical discharge devices

US4803397A · kind A · utility

1Cited by
3References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 10, 1987
Grant dateFeb 7, 1989
Priority date
Expiry dateAug 10, 2007

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01J1/28
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A dispenser cathode such as a metal capillary cathode for electrical discharge devices which has a hollow cylindrical head portion 1 which carries a porous emission wafer 3 of a refractive material at its upper end and covers a cathode cartridge 2 which contains an active material supply 4 and comprises an epoxy helical heater 5 surrounded by a metal sleeve 6. Two part division of the structure allows separate testing possibility of the emission wafer and the heater/supply cartridge and also allows an improvement in the heat transmission from the heater to the emission wafer. For this purpose, a hollow cylindrical head portion 1 is conically-shaped and expands outwardly toward the cathode cartridge 2 and the upper part of the cathode cartridge 2 is conically tapered so as to mate with the hollow cylindrical head portion and the two portions are connected together wherein their conical side walls are attached by welding in the upper portion of the drawn up metal sleeve. The dispenser cathode can be used in travelling wave tubes for example.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.