Impact of Indentation on the Performance of MgB₂ Round Wire

MgB₂ round wire is a promising material for future fusion Cable in Conduit Conductor applied in low magnetic field, due to its larger T-margin compare with NbTi. It's a competitive candidate for feeders, poloidal field or correction coils. Since MgB₂ is sensitive to strain, a short twist pitch cable pattern will be taken into consideration. During cabling and conductor manufacturing, the compression on the strand is inevitable, for a cable with short twist pitch can make more severe indentation on the strands. Previous studies have shown that indentation can caused degradation of the critical current of Nb₃Sn and Bi-2212 round wires. So the same research is performed on MgB₂ round wire, in this paper, the critical current of artificially indented samples is measured, and the results are compared with artificially indented Nb₃Sn, NbTi and Bi-2212 round wires.