Cable patterns, compaction, electromagnetic load, and reduction of coupling loss are investigated to improve the performance of NbTi, Nb₃Sn, MgB₂ and ReBCO based Cable-In-Conduit Conductors (CICC) for fusion magnets. For round Nb₃Sn and MgB₂ wires, the R&D for full-and sub-size CICC cables was carried out at in a collaboration between ASIPP and University of Twente. Different conductor designs were manufactured at ASIPP based on models developed by Twente. The so-called short twitch pitch “close-to-1-ratio” cable design was eventually selected and experiments on full- and sub-size CICC cables were carried out. For the selected cable pattern in sub-size CICCs; no decrease in critical current was observed from cabling, compaction, and electromagnetic load cycles.
For background magnetic fields in the 20 T range, Conductor on Round Core (CORC®) cables and wires, composed of spiraled high-temperature superconducting (HTS) REBCO tapes, wound in multiple layers, is one of the options in fusion magnet technology. They combine isotropic flexibility and high resilience to electromagnetic and thermal loads. Finite element (FE) and analytical models are developed to predict the performance of CORC® under axial and transverse load. As a basis for the models, extensive REBCO tape characterization has been performed to study the performance under axial, transverse contact and torsional loads. A parametric analysis is carried out by varying winding angle, Poisson’s ratio of the CORC® wire core, core diameter, and tape width. The FE model can be used to optimize the cable design for specific application conditions.
The results offer guidelines for the optimization of superconducting materials and cables for application in fusion.