The results of the second Chinese TF conductor sample

In the framework of the ITER qualification tests the second Chinese sample (CNTF2) was tested in the SULTAN facility. The sample was made of two identical ITER TF type cable-in-conduit conductor sections. Internal Sn strands offered by Western Superconducting Technologies Company (WST) were used for the conductor fabrication. The main characteristics of the conductor and the strand are presented as well as the sample assembly details. The test was performed in accordance with the ITER International Organization specified program. In order to evaluate the conductor performance, the current sharing temperature was measured at specified electromagnetic load cycling steps. Few voltage–current characteristics were measured with the aim of n-value estimation. Before cycling load, both conductor sections of CNTF2 showed different performance, but after 1200 cycles and warmed up and cool down, they showed identical performance: the current sharing temperature (Tcs) was 6.36 K, which exceeds ITER requirement of 5.7 K.

► The China second ITER TF conductor sample has been test in SULTAN laboratory.
► By using the electric method and calorimetric method to assess Tcs, the final minimum current temperature of conductor is about 6.36 K.
► The AC loss curves are different before DC tests and cycling, and they are identical afterwards.