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

Ando, Toshinari*; Kikuchi, Mitsuru

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.