| 摘要 |
<p>PURPOSE: To heat the whole construction of a cathode base effectively and enhance the heat conducting efficiency to a great extent by reducing the heat capacity of an impregnation type cathode structure, and using a sheet form heater. CONSTITUTION: A disc-shaped impregnated cathode base 1 and the first supporting cylinder 3 to support the cathode base are brazed to a cap-shaped cylinder having a cavity, in which a heater 4 is embedded with a heat resistant insulative substance 6 capable of undergoing a sintering process, and thus a cathode structure is formed. wherein the internal cap-shaped cylinder 5 for cavity formation having a smaller diameter than the cap-shaped cylinder is embedded at the same time as heater embedding, and the heater and internal cap-shaped cylinder are held in the cavity of the cap-shaped cylinder. Thereby the shape of the heater is simplified, and the heat conducting efficiency is enhanced by heating the whole construction from the rear surface of the cathode base.</p> |
