Fabrication of (6+1)-Structure Superconducting Cable Based On 30-Core MgB2 Superconducting Wire

30-core MgB2 superconducting wire with a diameter of 1.0 mm has been prepared by the conventional in-situ powder-in-tube (PIT) method. The metallographic analysis results show that the 30-core MgB2 wire has good uniformity in both transverse and longitudinal directions, and the critical current ( I c) and critical current density ( J c) at 4.2 K and 4 T reach 82.6 A and 7.3 × 104 A/cm2, respectively. Furthermore, (6 + 1)-structure MgB2 superconducting cables have also been successfully fabricated with different twist pitches ( T p) by the twisted and reacted (T&R) route, comprising six 30-core MgB2 wires around one copper wire in the center. The I c of the (6 + 1)-structure MgB2 superconducting cable with 50 mm T p reaches 467 A at 4.2 K and 4 T, suggesting no degradation of the MgB2 wire when self-field effects are taken into account.