Fabrication of 20 KA, 12 Tesla conductor using external Bronze process MF Nb3Sn

A MF Nb3Sn cabled condcutor with a design critical current in excess of 20 KA has been delivered to the Oak Ridge National Laboratory for stability test in the CWTX Facility. The 5.2 cm × 1.1 cm conductor, an adaptation of a 12 Tesla ETF design by Walker, et al is a 7 × 7 × 3 × 16 cable. The seven strand primary cables incorporate two 0.3 mm diameter external bronze process MF Nb3Sn strands and five barrier protected stabilizer strands. Critical current density in the active strands is approximately 5 × 10⁴A/cm²at 12 Tesla, 4.2 K.