CATHODE FOR ELECTRONIC TUBE

摘要

The conventional cathode for electronic tube has such a problem that the metal constituting the base material of the tube is thermally deformed and the fluctuation of the cut-off voltage becomes relatively large when an electronic tube is operated for a long time. In order to solve this problem, a cathode for electronic tube which can reduce the thermal deformation of the base material and does not allow the large fluctuation of the cut-off voltage is provided. The coefficient of thermal expansion of the metal constituting the base material (1) is made even by mixing the same metal (14) as that of a metallic layer (13) formed on the base material (1) in the metal constituting the base material (1), and the deformation of the base material (1) is suppressed by preventing the diffusion of the metal of the layer (13) to the base material (1).