Investigation of degradation mechanisms in CICCs

The performance of cable-in-conduit conductors often does not meet the anticipation extrapolated from the data of single strands. Various mechanisms are currently discussed as potential causes of this degradation. However, their quantitative influence in real-scale conductors remains to be determined. We investigated several mechanisms such as self-field effect, joint resistance scatter, and local strand degradation (e.g., by a local strain maximum in Nb₃Sn strands), using a recently presented model for the coupled electromagnetic and thermo-hydraulic analysis of forced-flow cooled multi-strand conductors. The significance of the electromagnetic diffusion length for the current distribution processes in multi-strand conductors is emphasized.