Superconducting coil with pure copper wires for thermal protection outside cable-in-conduit conductors

ケーブルインコンジット導体の外で純銅で熱的な保護を行う超伝導コイル

安藤 俊就*; 菊池 満

Ando, Toshinari*; Kikuchi, Mitsuru

核融合炉用超伝導コイルの導体の高電流密度化とコイルが常伝導状態に転移した時にコイルに蓄積した磁気エネルギーを消費する外部抵抗器を縮小するために、導体の常伝導状態に転移の際に電流のバイパスとして導体内に備えてある純銅線を導体から取り除き、その代わりに常伝導コイルを超伝導コイルの内側に配置した超伝導コイル・システムを考案し、その実現性を検討した。その結果、導体の断面積で約35%に縮小が可能であること、また、外部抵抗を約40%に縮小できることが示された。

In order to realize a low cost TF superconducting coil system for tokamak fusion reactors, the design of TF superconducting coil with a copper coil in place of pure copper wires within cable-in-conduit conductors is considered, which are needed for the thermal protection. This consideration is carried out under the condition that hot spot temperature of conductor is less than 250 K and a plasma-confinement vacuum vessel has no damage during the TF coil fast discharge in the ITER TF coil design. As the result, it is found that the conductor area is reduced by 35 % and the copper coil is installed into the original coil case together with a TF coil winding. An external resister system is reduced by around 40 % of the original system because 40 % of magnetic energy (40 GJ) stored in the ITER TF coil is dissipated into the copper coil during the fast discharge.