Speaker
Description
In this paper, the km-grade 30-core MgB2 superconducting wire with a diameter of 1.0mm has been prepared by conventional in-situ powder-in-tube method. The metallographic analysis results show that the 30-core MgB2 wire has very good uniformity in both transverse and longitudinal directions, and the critical current (Ic) and critical current density (Jc) reach 95 A and 2.1×105 A/cm2 at 4.2 K and 4 T, respectively. Furthermore, the (6+1)-structure MgB2 superconducting cable has also been successfully fabricated with different twist pitches (TP) by the twisted and reacted (T&R) route, which uses six pieces 30-core MgB2 wires and one copper wire in the center. The critical current (Ic) of the (6+1)-structure MgB2 superconducting cable with 50 mm TP reaches 476 A at 4.2 K and 4 T in this work.
