Grid controlled electron source and method of making same
Lanthanated thermionic cathodes
Thermionic electron source with bonded control grid
Electron tube with dispenser cathode Patent #: 4165473
ApplicationNo. 06/037257 filed on 05/09/1979
US Classes:313/268, Insulating spacer between discharge electrodes313/107, Nonemissive material313/250, With spacer between electrodes or electrode supports313/348, Foraminous electrodes (e.g., grids) or shields445/58With coating, e.g., providing protective coating on sensitive area
ExaminersPrimary: Chatmon, Saxfield Jr.
Attorney, Agent or Firm
International ClassesH01J 19/00 (20060101)
H01J 19/42 (20060101)
AbstractThe variety of technologies that have been applied in the development of a onded grid cathode are described. These include chemical vapor deposition of tungsten, molybdenum, iridium, BM, and Si3 N4 on both sides of a sintered tungsten cathode disk. Zirconium and titanium getters have been used to eliminate nitrogen evolution problems. Films of Si3 N4 have been added to the insulation to prevent calcium and barium diffusion into the layer and maintain adequate resistivity and breakdown strength. Plasma etching was introduced as a method of removing Si3 N4 from the cathode pores.