Mechanical Analysis of CORC CICC for Future Fusion CS Magnet

With continuous improvements in the superconducting performance and technical maturity, High Temperature Superconductors (HTS) are believed to meet the challenges of future fusion magnets. The Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) has been designing several types of high current REBCO Conductor On Round Core (CORC) Cable-In-Conduit Conductors (CICCs) for use in Central Solenoid (CS) magnet of a next-generation tokamak device. One preferred structure of CICC consists of six CORC sub-cables embedded in the spiral grooves of a copper structural part. This CICC, rated for 45 kA at 4.2 K and 20 T, is subjected to great electromagnetic forces. Compared with stainless steel, copper has better thermal conductivity but poorer mechanical performance. Therefore, the mechanical robustness of conductor in low temperature and electromagnetic environment needs to be evaluated. In this paper, the mechanical analyses of this conductor is performed by Finite Element Method (FEM), and the effect of pitch on conductor stress is analyzed. These results will provide mechanical information for selecting the relatively suitable conductor scheme.