ABSTRACT
Oxide superconductors are expected to be applied in many electric power fields, among which a current lead is very promising. The current lead transports power between a power source at room temperature and the superconducting device within a cryostat, and it is commonly made of Cu, which introduces a large amount of heat into the superconducting device. Because it is needed to minimize this heat leak to reduce the amount of cryogenic fluid boiled, oxide superconductors having merits of no Joule heating below the critical temperature (Tc) and of low thermal conductivity as compared with Cu are favorable for the current lead. However, applications of oxide superconductors have been limited because of their low values of the critical current (Ic).
