Hybrid Magnet Design Consisting of a 20 T Superconducting Outsert and a 15 MW Resistive Insert

摘要

Internally reinforced ${rm Nb}_{3}{rm Sn}$ strands with CuNb-reinforcing stabilizer $({rm CuNb/Nb}_{3}{rm Sn})$ have been developed for realizing a compact high-field superconducting magnet. The Rutherford flat cables composed of sixteen strands were made with a 0.8 mm diameter ${rm CuNb/Nb}_{3}{rm Sn}$ strand. The designed critical current of the ${rm CuNb/Nb}_{3}{rm Sn}$ Rutherford flat cable is $I_{rm c}=1890 {rm A}$ at 13 T and 4.2 K in case of an ordinary heat-treatment at 670 $^{circ}{rm C}$ for 96 h, which is two times higher than an operation current desired for safety margin.