Current-Carrying Capability and Magnetic Behavior of the HTS Twisted Stacked-Tape Conductor Cable for the Compact Fusion Reactor

The concept of the high temperature superconducting (HTS) twisted stacked tape conductor (TSTC) cable for fusion has been developed during recent years. The cable is demonstrated to have a stable cable critical current under extreme trial conditions with high electromagnetic force levels and multiple cryogenic thermal cycles. The remaining question is how to enhance the current-carrying capability and magnetic properties of the cable. In this article, three specific TSTC cables with the same twist pitch have been designed. Numerical studies of current-carrying capability and magnetic behavior of these cables have been carried out by employing a T-A formulation model and a H-homogenized formulation model which are based on the finite element method. The two models consider the variation of the critical current density with perpendicular and parallel magnetic fields, and temperature influence on the critical current density has been considered as well. these models have been validated with experiment data and a good fitting curve was obtained. Results show that the 4-slot TSTC cable has a better magnetic behavior compared to the 3-slot and 5-slot TSTC cables, in spite of a better current-carrying capability of the 5-slot cable. The study is of great significance for the research and development of the TSTC cables for compact fusion reactors.