| 摘要 |
PURPOSE:To enable sufficient thermonic emission even under low temperature, by employing a boride as an impregnation material while employing a carbide as a structural member. CONSTITUTION:One end of a cylindrical hot cathode 8 for follow-cathode discharge is connected through an intermediate member 7 to one end of a cathode container 1 while an end board 9 having an orifice 9a is fixed to the opening at the other end of the hot cathode 8. A heater 5 is contained in the hot cathode 8. The hot cathode 8 is formed by impregnating the boride such as LaB6 into the carbide such as WC. Since the boride having low work factor and strong against the ion shock is employed as the kmpregnation material, sufficient thermionic emission is achieved even under relatively low temperature. |
