CICC manufacturing technology as a factor affecting Tcs stability during full-size testing

The test results of the ITER toroidal field conductors demonstrated a decrease of the current sharing temperature (T_cs) with an increase in the number of electromagnetic cycles in general. This is associating with several factors. One of them is the superconducting Nb₃Sn filaments cracking and another one is the redistribution of the relative deformation of the Nb₃Sn strands under Lorentz forces. Despite these factors, some conductors have shown the absence or significantly less degradation of T_cs during electromagnetic cycling. This article considers another possible reason for a more stable conductors T_cs behavior, namely, the local compression of Nb₃Sn wires in the cross section of a conductor. In this article presents the results of a quantitative analysis Nb₃Sn superconducting filaments cracking of strands extracted from a conductor that has passed electromagnetic cycling and the model of a conductor compaction, as well as calculation results based on this model are presented also.