| 摘要 |
<p>PURPOSE:To provide an electron gun having a large cathode. CONSTITUTION:In a boride cathode 1 of rare earth metal heated to emit an electron, cathode dimension in a part, brought into contact with a heater 3 of carbonizing thermosetting resin, is formed smaller than the cathode dimension in the other part to fix the cathode by using the thermosetting resin 2. In this way, an electron gun of obtaining large crossover dimension can be provided.</p> |
