Electrical Performance of Glass Insulated Transfer Tube of Cryogenic Liquid

A superconducting power cable is one of the promising ways for transmitting huge electric power effectively in the future. We proposed the new superconducting cable design with a similar electrical insulation structure to the conventional extruded polyethylene cable in order to exploit the excellent electrical insulation capability of polyethylene at cryogenic temperature. Electrical insulation of the cryogenic liquid transfer tube is required for the long term voltage test of the cable, since the cryogenic liquid has to be supplied from the coolant container of the earthed potential to the high voltage cable. The coaxial glass insulated transfer tube with vacuum thermal insulation has been developed for handy transport of cryogenic liquid between apparatuses at different electrical potentials. The fundamental electrical characteristics of the glass insulated transfer tube were investigated. Furthermore, this newly developed transfer tube has been incorporated into the superconducting power cable system with success.