Heat Treatment of Two-Turn Nb3Sn Superconducting Coil

A heat treatment system was built at High Magnetic Field Laboratory, Chinese Academy of Sciences (CHMFL) for the heat treatment of large-scale Nb₃Sn superconducting coils and conductors. In order to evaluate the manufacturing technique of the joints for the Nb₃Sn CICC, a two-turn Nb₃Sn superconducting coil with two superconducting joints had been developed. A two-turn coil together with several Nb₃Sn witness samples was heat-treated. Experimental and finite elemental analysis was also discussed. The results of the measurements met the requirements of the magnet design.