HIGH-STRENGTH NB3SN CONDUCTORS FOR HIGH MAGNETIC-FIELD APPLICATIONS

Developments in recent years of Nb3Sn superconducting materials have allowed magnet designers to consider magnets for fields up to 20T. As the magnetic field or the operating current increases, so do the electromagnetic stresses experienced by the superconducting wire in the magnet windings. At strains exceeding the elastic tolerance of Nb3Sn, irreversible damage and current density (J(c)) degradation, will follow. A relatively high conductivity copper based material which retains its high strength after reaction heat treatment, has been used to replace some of the copper stabilizer, both on the outside of the conductor and between the filaments. Some of the effects of this change on the mechanical and electrical properties of composites are reported.