| 摘要 |
<p>PURPOSE:To obtain an electron tube cathode to be used in a high current densi ty, by furnishing a function to produce free Ba from a compound oxide produced by scandium oxide scattered in the first electron emission substance layer, and a function to enhance the electroconductivity of the electron emission sub stance layers. CONSTITUTION:An electron emission substance layer 2 coating a nickel base 1 is formed by laminating the first electron emission substance layer 2a compris ing an alkaline earth metal oxide containing scattered scandium oxide Sc2O8 powder, and the second electron emission substance layer 2b comprising an alkaline earth metal oxide with no scandium oxide. Since the first electron emission substance layer 2a prevents a deterioration of electroconductivity owing to the generation of an intermediate layer, and the second electron emis sion substance layer 2b produces separate Ba and operates in the same mecha nism as the conventional way, a stable initial property can be obtained.</p> |
