The superconducting property of Nb3Sn strands is very sensitive to strain. The transverse electromagnetic loading has been considered as a major origin of the degradation of Nb3Sn cable-in-conduit conductor (CICC) due to the periodic local bending. The degradation of each strand due to this bending should be evaluated to calculate the performance of a CICC. Thus, an analytical model considered with the plastic deformation of copper and filament breakages was developed. The calculated results show good agreement with strain distribution measured by the neutron diffraction for uniformly bent Nb3Sn strands. In addition, the critical current calculated by this model shows agreement with the test results.
Acknowledgement: The neutron diffraction experiments were conducted at the MLF of J-PARC with the proposal number of 2012B0017.