Test Facility for Critical Current Measurement of Superconducting Conductors

High-current superconducting conductors are widely used in fusion magnets, high-energy accelerators, and superconducting power transmission. In order to carry out experimental research on new high-current conductors such as Bi₂Sr₂CaCu₂O_x (Bi-2212) Cable-in-Conduit conductor (CICC), YBa₂Cu₃O_7-x (YBCO)-twisted stacked-tape cable (TSTC) conductor, and Rutherford cable, we have developed a new test facility for their critical current measurement. The key component of the facility is a 6-T dipole magnet with a useful bore of 80 mm, which is connected through a pair of 6-kA binary-current leads to the external dc power supply. The homogeneous high field length is 400 mm with uniformity better than 98%. Instead of the traditional expensive dc power supply and complicated current leads, a superconducting transformer is used to supply the test sample with current up to 30 kA. Quench detection and protection system are also used for both the primary coil of superconducting transformer and the 6-T dipole magnet. An NbTi Rutherford cable with ten strands has been tested to verify the test facility. The status of our test facility and the test results are described in this paper.