Quench Simulation of REBCO Cable-in-Conduit Conductor With Twisted Stacked-Tape Cable.

Quench protection is a critical issue for magnet using high-temperature superconducting (HTS) materials such as REBCO. For cable-in-conduit conductor (CICC) with twisted REBCO tapes, which is considered for high-current HTS conductor for fusion magnet, the anisotropic critical current density (Jc) of tape and complex conductor layout will further complicate the quench behavior. The CryoSoft code THEA is used to simulate the quench behavior of various subscale CICCs in view of a quench experiment in SULTAN facility. The CICCs are composed of twisted tape stack assembled into copper shell (strand). It has been found that neglecting the anisotropy of Jc in quench simulation will significantly underestimate the hot spot temperature by about 40 K. Therefore, it could leave potential risk to damage the magnet. It is also shown that the thermal contact resistance between strand and the steel jacket (the conduit) plays a very important role on quench behavior. The hot spot temperature can be reduced by more than 100 K if the thermal resistance is reduced by two order of magnitude. On the other hand, variations of interstrand electrical and/or thermal resistance have only very little influence (few kelvin). [ABSTRACT FROM AUTHOR]