Re-test of the TFAS1 sample with solder filled extremities

TFAS1 (Toroidal Field Advanced Strand) sample is composed of two Nb3Sn cable-in-conduit conductors intended to be used in ITER Toroidal Field Coils. This sample was tested in the SULTAN facility in order to benchmark the performance in years 2005-2006. An early voltage evolution was observed in both conductors during current ramp up, which makes it difficult to assess correctly the conductor performance. In order to improve the voltage behavior, the two terminations and two halves of the joint were filled by solder at CRPP with the aim to achieve a more uniform current distribution in the conductors. Thereafter, the TFAS1 sample was retested in the SULTAN facility. The retest revealed an unexpected increase of resistance after solder filling at the conductor extremities. As a consequence the voltage slope did not disappear, and further reduction of conductor performance was observed. The results of the retest of the TFAS1 sample with solder filled extremities are presented and discussed in this paper. (authors)