Effect of strain in multifilamentary Nb3Sn conductors up to 23 T

Measurements of critical current of multifilamentary Nb3Sn conductors as a function of strain were made in flux densities up to 23 T. The advantage of using high fields is that conductors with high critical current can be investigated without thermal instabilities. The results show that the upper critical field Bc2which is about 2 T higher than the extrapolated varies with strain in approximately the same manner as . A residual resistivity which appears in fields near Bc2is strongly strain dependent indicating the existence of Nb3Sn regions with slightly lower critical field.