| 摘要 |
PURPOSE:To increase the life of a cathode for an electron tube by coating a base principally composed of nickel with an electron-emitting substance layer which is principally composed of the oxides of alkaline earth metals including barium and containing 0.1-20wt% of a complex oxide of the oxides of rare earth metals. CONSTITUTION:A suspension is prepared by adding 0.1-20wt% of a Ba2SC4O9 powder or Ba3Y4O9 powder to a ternary carbonic salt of barium, strontium and calcium. This suspension is applied to a base 1 principally composed of nickel by spraying in a thickness of about 80 microns. Next, the base 1 is coated with an electron-emitting substance layer 2 through the decomposition process from carbonate to an oxide and an activation process whereby the oxide is reduced partially. Thus, it is possible to increase the life of the cathode under the operation at high current density. |
