Ceramic dielectric type vacuum container

Object: To cut off an induced current generated in a ceramic dielectric type vacuum container for a plasma containment device, thereby enhancing plasma efficiency and preventing generation of electromagnetic interactions in the vacuum container and between coils. Structure: Between a plurality of vacuum container elements and a ceramic dielectric body inserted therebetween are formed a sealing device and a secondary vacuum chamber through a bellows made of more than two materials different in coefficient of thermal expansion, whereby the vacuum container elements are electrically insulated from one another to restrain an electric current within the vacuum container induced by the plasma and exerting a fastening force resulting from the difference in thermal expansion of the bellows at the time of high temperature upon between the container elements and the dielectric body to maintain ultrahigh vacuum within the container. (Kamimura, M.)