Feedthrough insulating bushing for electrical discharge appts. - has coarse thread on inner surface to increase electrical leakage path and is made from ceramic

摘要

The feed-through insulator bushing may be used in an ion getting pump or high voltage electric discharge arrangements. The anode (7) connection (4) enters the anode chamber (1) through a ceramic bushing (2) with vacuum seals at each end. In order to increase the internal electrical leakage path ridges are incorporated in the insulator bore in the form of a coarse thread (8). By thus increasing the path length the total insulator length may be shortened, and the whole assembly can be made smaller. The thread form (8) also ensures that any deposits due to evaporated conducting particles coming from the anode are only deposited on one face of the thread. the resistance of the assembly to this form of contamination is thus increased.