Updated design of a 0.6 m bore `wind and react´ 12 T coil

The design of a 0.6-m bore wind-and-react Nb₃Sn solenoid was presented previously as part of the European R&D program on fusion magnets. Since then tests on the prototype base strands have been performed, with results showing that the specifications concerning J_c and AC losses were met, but the residual resistivity ratio (RRR) (273 K/20 K) was a factor of two lower than expected. By reducing the conduit thickness, the superconducting cable (cable-in-conduit conductor type) has been modified to accommodate an increased number of base strands, from 117 to 128 plus 16 high purity (OFHC) copper wires. A stress analysis of the new design has been performed, introducing into the ABAQUS code the elastic constants of each component of the CIC conductor. A sensitivity analysis of the quench behavior relative to different thermal disturbance durations and quenched conductor lengths has been performed using a 1-D code. Results of calculations as well as some experimental results concerning strand properties, cable manufacturing, and insulation tests are reported