| 摘要 |
<p>PURPOSE:To secure a distance between a heater and a container and secure the strength of their connection by protruding one end part of the heater from an insulation while applying it in part of the container, providing a recess part in the container for the end part of the heater fitted in, and welding the end part of the heater at the recess part. CONSTITUTION:For an impregnation type cathode, one end part 26a of a heater 26 is protruded from an insulation 27, while it is applied to a supporting cylinder 24 of a container, and the end part 26a of the heater 26 is fitted in a recess part 34b between end parts 34a of a ring 34 provided at the supporting cylinder 24, and it is arc welded at this recess part 34b. Their contact with each other can thus be secured by the recess part 34b of the ring 34 securely if the end part 26a of the heater 26 and the supporting cylinder 24 are not attached tightly to each other directly, and their weld with each other can be achieved securely and strongly. Tight attachment of the end part 26a of the heater 26 to the supporting cylinder 24 need not be secured, and the distance between the heater 26 and the container 25 can be secured priorly instead, thereby possibility of dielectric breakdown of the insulation 27 is eliminated, and insulation property is improved.</p> |
