| 摘要 |
A cathode having a short heating time and a long lifetime for an electric discharge tube is provided. The cathode comprises a metal (particularly nickel) support base coated with a layer of potentially electron-emissive material, which support base has a thickness ranging between 20 and 150 (my)m, while the metal crystallites have a size which does not permit of any further crystallite growth or recrystallization. Particularly, the crystallites of the support base have a size which corresponds to the thickness of the support base. The cathode is obtained by a method in which the recrystallization thermal treatment is effective to prevent additions in the metal of the support base from forming oxides to a depth which is further than 1 micrometer from the surface.
|
