Development of In-situ Processed MgB₂ Superconducting Wires

Abstract

The MgB₂ wire has a great potential as a low-cost superconducting wire, which does not require cooling with liquid helium. We have been developing In situ MgB₂ wires, which have practical J_c and J_e at 10-20 K in a 5-T or lower magnetic field. A few prototype coils and magnets were made by the Wind&React method with km-class wires, which have a good homogeneity and a large quench energy margin. By using this margin, a magnet for klystron and a fast ramp-up MRI magnet were demonstrated successfully. An MgB₂ magnet for Finger MRI was operated in a persistent mode with a superconducting joint. For realizing MgB₂ coils made by the React&Wind method, the strain-tolerance of the reacted wire should be improved.