Development, Design, and Fabrication of Hybrid High-Temperature Superconducting Leads

Hybrid high-temperature superconducting (HTS) current leads employing a conventional vapor-cooled lead upper stage and a HTS lead lower stage made from YBCO compound were fabricated and then testing in magnetic fields as high as 9 T, with currents up to 750 A, at liquid helium temperature of 4.2 K. Various current lead performance parameters were measured, however the bulk of the work focused on the fabrication of melt-textured YBCO for use in practical current leads, and testing the HTS material in high background magnetic fields. This work was sponsored by the U.S. Department of Energy (DOE) under a Small Business Innovation Research (SBIR) Phase I grant.