Considerations in Designing and Using Superconductors with High Resistivity Matrices

摘要

Superconductors are often designed with matrices of much higher residual resistivities than copper for reasons of manufacturing (multifilamentary Nb sub 3 Sn in CuSn bronze) or loss reduction (mixed matrix NbTi with Cu and CuNi). The high resistivity matrix may complicate or degrade contact resistances at the joints, generate excess heat, reduce the stability of the conductor, and interfere with the observation of flux flow resistivities in the 10 exp -12 omega -cm region. The minimization of these effects is discussed, presenting both simple and more refined models for the current transfer length, and it is shown how variations in transfer length (with current), particularly under significant self field conditions, can mimic flux flow resistivity. (ERA citation 02:046063)