Development of Resin-impregnated HTS Current Leads for MAGLEV

High temperature superconductors (HTS) have been successfully applied to current leads. Low thermal conductivity and high critical current density (Jc) are the characteristics desired for such applications. We have developed Y-Ba-Cu-O current leads for MAGLEV. The mechanical properties of Y-Ba-Cu-O bulk superconductors are improved by epoxy resin impregnation. In order to reduce the stress caused by the relative displacement between the inner vessel and the radiation shielding plate of superconducting magnet, flexible copper cables were connected in series with a Y-Ba-Cu-O current lead. We were able to feed a current up to 1000 A at 77 K, and then we measured V-I characteristics. The present results show that the bulk Y-Ba-Cu-O can be applied to the current leads for MAGLEV.