摘要 |
PURPOSE:To retain the insulation of a cathode sufficiently, and prevent any noise wave from being discharged by providing, close to a supporter supporting the cathode, a molded carbon body the surface layer of which is denatured into SiC. CONSTITUTION:A cathode-side insulator 7 is held between a cylindrical metal body 8 connected to an anode, and metal pieces 6a and 6b so that it insulates the body 8 and the metal pieces 6a and 6b. A center support 4 and a side support 5 are fixed with an insulating spacer 9 so that any excessive shift of a cathode which might be caused by external vibrations or shocks is prevented. The insulator 7 and the spacer 9 consist of base parts prepared by molding carbon into given shapes, and surface layers prepared by treating and denaturing the entire surfaces of the base parts into SiC. |