Preparation activities of procurement for ITER superconductors

Takahashi, Yoshikazu; Isono, Takaaki; Koizumi, Norikiyo; Matsui, Kunihiro; Hamada, Kazuya; Nunoya, Yoshihiko; Nabara, Yoshihiro; Oshikiri, Masayuki; Nakajima, Hideo; Kawano, Katsumi; Okuno, Kiyoshi

The toroidal field (TF) coil system of the International Thermonuclear Experimental Reactor (ITER) consists of 18 D-shape coils. The operating current, the maximum field and the stored magnetic energy are 68 kA, 11.8 T and about 41 GJ, respectively. NbSn cable-in-conduit conductor (CICC) with a central channel is used. The superconducting cable consists of 900 NbSn strands and 522 copper strands, and they are cabled to a 5 stage cable with the final 6 fifth-stage subunits cabled around a central cooling spiral. Five long conductors with a length of 760 m and 2 short conductors with a length of 520 m are used for one coil. Ninety-five long conductors and 38 short conductors will be fabricated for the TF coil system including one spare coil. Japan will procure 25% of these TF conductors. Mass production trial of high Jc strands was successfully completed in 4 companies in Japan. The superconducting performance of full-size conductors manufactured in the mass production trial will be tested at the operating condition in May 2007. We will start the procurement of the conductors after the superconducting performance of these conductors is confirmed in the test.