Development of metallic superconducting tapes and wires

Abstract

Metallic superconductors, MgB₂ and Nb₃Al, are interesting materials from the viewpoint of practical applications. MgB₂, whose transition temperature is much higher than those of conventional metallic superconductors, is promising as a conductor in cryogen-free superconducting devices. Nb₃Al, on the other hand, shows much less sensitivity to mechanical stress and strain and higher high-field critical current density, J_c, than Nb₃Sn. This makes Nb₃Al favorable for high-field large superconducting devices applications. 1km-long tapes and wires have already been fabricated for both types of superconductors, and small coils have been constructed using these conductors. Further Jc improvement will enable us to develop practical applications of these superconducting tapes and wires.