Influence of strand surface condition in interstrand contact resistance and coupling loss in NbTi-wound Rutherford cables

Presented in this work are the results of directly measured and AC-loss-derived interstrand contact resistance (ICR) measurements performed magnetically or resistively on bare-Cu and coated-strand pairs, calorimetrically on 11-strand Rutherford cables wound with strands that had been coated with various metallic and insulating layers, and calorimetrically and magnetically on 28-strand Rutherford cables (LHC-type) wound with bare-Cu-, Ni-, and stabrite-plated strands. Comparisons are made of the effects of various conditions of heat treatment, HT (time and temperature), and pressure (applied during HT and then either maintained or re-applied during measurement). The resulting ICRs are compared and interpreted in terms of the oxide layer on the strand coating and its response to curing conditions