| 摘要 |
PURPOSE:To realize an impregnated cathode to allow practical use, with a low acetivation temperature, a short activation time, and a lower operating temperature, by providing thin films including a specific substance on the surface of the impregnated cathode. CONSTITUTION:On the surface of an impregnated cathode in which an oxide including barium is impregnated in the pores of a heatproof porous substance, plural layers of a thin film including tungsten and scandium tungstate, and a thin film including tungsten and an oxide including barium are provided. The thickness of each thin film to compose the plural layers in made in the scope 10 to 500 nm, and the whole thickness of the thin film in the plural layers is made in the scope 50 to 1000 nm. Furthermore, when the above heatproof substance is made into a porous body mainly of tungsten and including at least one sort of titanium, vanadium, chrome, yttrium, zirconium, niobium, hafnium, and tantalum, the effect of the cathode is made more remarkable. |
