Development of a YBa₂Cu₃O₇ filament leads unit

In order to reduce thermal inputs through many measuring copper leads, we intended to fabricate a measuring leads unit using very fine YBa₂Cu₃O₇ filaments. The long YBa₂Cu₃O₇ filaments were prepared by a textile fiber spinning method for the oxide precursor. The 60 filaments with a size of 100 μm in diameter and 60 mm in length were attached onto three fiber-reinforced polymers, and were covered with epoxy resin. Both ends of the YBa₂Cu₃O₇ filament were soldered with pin connectors through copper leads with 0.1 mm in diameter. The YBa₂Cu₃O₇ measuring leads unit of 60 terminals was cooled by a pulse tube cryocooler. The newly developed YBa₂Cu₃O₇ measuring leads unit demonstrates the extremely small heat loads of 1/10 in comparison with conventional copper measuring leads.