Review of the results of the ITER Toroidal Field conductor R&D and qualification

An R&D program is being carried out in view of the qualification of the Toroidal Field (TF) coil conductor. It consists of an extensive characterization of several Nb3Sn strand candidates, the cabling of those strands into prototype TF conductors with various combinations of twist pitch and void fraction and the measurement of the performance of conductor short samples in representative condition of transport current, magnetic field and temperature. Industries and laboratories are involved worldwide in this R&D program which is expected to provide the basis to finalize the TF conductor design. The Nb3Sn strands proposed by each of the six Participant Teams involved in the procurement of the TF conductor will then be qualified in the final cable configuration by the successful test of a short sample in the Sultan facility. The status and the first results of the R&D program are presented together with the qualification plan.