Development and performance of high-temperature superconducting CORC® cables with CFD REBCO tapes

Increasing the normal zone propagation velocity (NZPV) in superconducting cables based on rare earth barium copper oxide (REBCO) tapes is expected to cause a paradigm shift by enabling the development of faster and more reliable quench detection systems to mitigate the development of destructive hot spots. Furthermore, a higher NZPV is beneficial in terms of fault current limitation capabilities by accelerating the homogenization of the quench in superconducting power devices. One way envisioned to increase the NZPV of cables based on REBCO tapes is the current flow diverter (CFD) concept. A Conductor on Round Core (CORC (R)) cable made with CFD REBCO tapes, called CFD CORC (R) cable, and a CORC (R) cable made with regular REBCO tapes, were fabricated and tested. The critical current of the CFD and regular CORC (R) cables were obtained at temperatures ranging from 67 to 77 K in self-field. Measurements showed that the NZPV was increased by a factor of 4-4.5 in the case of the CFD CORC (R) cable. Furthermore, the results suggest that the NZPV depends only on the applied current, similar to what has been observed previously on single REBCO tapes. These results demonstrate the successful integration of CFD REBCO tapes in CORC (R) cables, without compromising their superconducting properties or their enhanced NZPV. The possibility of enhancing the NZPV of REBCO-based cables could facilitate quench detection, which remains an important issue in HTS magnet applications. This advancement also holds promise for the fault current limitation functionality of CORC (R) cables.