Cathode for an electric discharge tube
AssigneeU.S. Philips Corporation
InventorPetrus J. A. M. Derks
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Abstract
Cathode for an electric discharge tube having a short warm-up time and a long lifetime. 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 .mu.m, and metal crystallites having a size which does not permit of any further crystallite growth or recrystallization. Preferably, the crystallites of the support base have a size which corresponds to the thickness of the support base.
Claims9
A cathode for an electric discharge tube, comprising a metal support base having metal crystallites and coated with a layer of potentially electron-emissive material, characterized in that the support base has a thickness ranging between 20 and 150 .mu.m, and the metal crystallites of the support base have a size which does not permit any further crystallite growth or recrystallization.
Dependencies are inferred from the claim text.