Impregnated cathode prodn. - by sintering metal powder to form pellet, fixing in cathode ring and impregnating pellet

摘要

Prodn. comprises (i) producing a porous pellet (6) or platelet with pores by sintering a metal powder at a high temp. in a reducing atmos.; (ii) using the porous pellet with fixed position in a cathode ring (2') made of an oxidisable metal material; and (iii) impregnating the pellet with an electron radiating material, which reacts with the oxidisable material of the cathode ring, so that a solid connection between the pellet and the cathode ring is formed. Oxidisable material is pref. Si, Ni or Cr. USE/ADVANTAGE - Impregnated cathode obtd. can be used in oscillographs, which require high cathode currents, and also in electron tubes used in TVs. Picture prodn. time is reduced.