Design consideration of the ITER-TF coil with a react-and-wind technique using Nb3Al conductor

The ITER-TF coil requires a generation of 12.5 T in a size of 12 m x 18 m. For such a high field-large coil, the applicability of Nb3Al conductors was considered with a react-and-wind technique which realizes high reliability and low cost for the coil fabrication. The maximum bending strain on the Nb3Al conductor in use of this technique is 0.39%. Ic degradation due to the strain is expected to be below 5%. The limiting current is estimated as 65 kA for 60 kA operation current. Ac loss in the TF coil with Nb3Al conductor is almost the same as with Nb3Sn conductor