Design of multifilamentary Nb3Sn superconductor tailored to the requirements of a dc superconducting power transmission line

There are at least four fundamentally different layouts for Cu-stabilized multifilamentary Nb3Sn superconductors. Multiple stacking further increases the possible permutations and combinations. The basic designs with respect to compound formation, stability, reduction of current transfer resistances, flexibility, and wire strain are analyzed. As a result, a very limited number of geometries for the conductor that will be suitable for use in the subcables of a dc superconducting power transmission line operating in the 10 to 14 K range and at the relatively low self-fields of 0.2 to 0.6 T are specified.