Conductor Performance of CCCN3, CCCN4 and CCCN5 Samples for ITER CC Coils

Abstract

The conductor for the ITER correction coils (CCs) is manufactured in China and is tested in the SULTAN facility. The third China CC conductor for the qualification SULTAN test sample (CCCN3) was prepared from a 200-m-long CC conductor unit length (Phase II). The fourth and fifth China CC conductor samples for SULTAN testing (CCCN4 and CCCN5) were prepared from the 576-m-long production unit lengths (Phase III). The current sharing temperature $T_{cs}$ test results show that the sections of CCCN3, CCCN4, and CCCN5 have high $T_{cs}$ performance. Using the electrical method, the $T_{cs}$ was 7.13 K for CCCN3, 7.10 K for CCCN4, and 7.09 K for CCCN5 at the ITER reference test conditions, i.e., at ${B}_{\mathrm{sultan}}=3.7 \text{T}$ and current equal to 10 kA $({B}_{\mathrm{peak}}=4.0 \text{T})$ . Even after the 2000 electromagnetic load cycles for CCCN3 conductor and 1000 electromagnetic load cycles for CCCN4 and CCCN5, the $T_{cs}$ performance of all samples did not changed appreciably. Based on the CC conductor sample test results at 10 kA and at different fields, the $T_{cs}$ was extrapolated to the peak field ${B}_{\mathrm{peak}}= 4.1 \text{T}$ and current equal to 10 kA. The extrapolated $T_{cs}$ is 7.07 K for CCCN3, 7.05 K for CCCN4, and 7.03 K for CCCN5. The $T_{cs}$ performance for all conductors is higher than the ITER acceptance criteria of 7.00 K.