Interstrand coupling and magnetization in Nb$_{3}$Sn Rutherford cables

It is well known by now that interstrand coupling in NbTi Rutherford cables can be suppressed by separating the strand layers with an "insulating" foil or core, typically of stainless steel (SS). Based on the results of an extensive series of studies of NbTi cables with coated strands and cores, the LASM group and its collaborators went on to measure the coupling losses and associated magnetizations of Nb$_{3}$Sn-wound cables incorporating various kinds of cores and several core widths. In Nb$_{3}$Sn cables the relatively large product of critical current density and effective strand diameter (Jc.deff) dictates a relatively large low-field persistent current magnetization. The relationship of this to the coupling magnetization at low- and high fields is discussed.