Development of a superconducting joint technique between CIC conductors for poloidal coil of large helical device (LHD)

A solid state bonding technique been developed for the large superconducting joint of LHD poloidal coils. Low electrical resistance, high superconducting stability and compactness are required for the joints between pancake coils. All NbTi strands of cable-in-conduit (CIC) conductors were jointed directly and at one time by the proposed technique. From the critical current test with the real scale joint model, it is shown that quench current of this joint is about 1/3 times of the conductor critical current. This paper describes the main points in manufacturing the joint and evaluation of the quench current.<
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