Improvement of Joint Structure for Mechanical Butt Joint of Stacked BSCCO 2223 Cable

A concept of remountable HTS magnet has been proposed to simplify fabrication of a superconducting magnet for a fusion reactor and to reduce maintenance cost of the reactor. For realization of the remountable HTS magnet system, mechanical butt joint of a stacked BSCCO 2223 cable has been investigated experimentally with large joint stress. In this study, 10 layered BSCCO 2223 cable with copper jacket is used as a test cable, and the roughness of joint surface is controlled quantitatively by using several different particle sizes of abrasive particles. Then the relation between the joint stress and resistance is evaluated through the mechanical butt joint test of the cable under several experimental conditions. Although dependence of the joint resistance on the joint stress is observed the relationship between roughness and joint resistance is not observed clearly due to not coincidence in surface flatness of the test cables.