  Characterizing critical current IC of Nb3Sn strands as function of a strain
is very important for large high field superconducting magnet applications such
as the superconducting outsert coil of the series-connected hybrid at the NHMFL
and the ITER magnets. Apparatuses for measuring IC versus longitudinal strain
and transverse stress have been developed and used at the NHMFL. We have
characterized the IC strain sensitivities of a few candidate strands for the
series-connected-hybrid. In addition, IC irreversibility strains are measured
for the recently developed ITER high JC strands. The different strain
sensitivities for different strands are discussed.
