3D FEM analysis of inter-strand coupling losses in Rutherford cables with composite core

Improved Rutherford cables have recently been proposed for magnets for experiments of high energy physics. They have either a sheet of stainless steel or a composite metal sheet as a core put in the usual Rutherford cable. The cable with this composite core sheet in it is a candidate for a new cable with both low losses and high stability. In order to estimate the interstrand coupling losses produced in this cable, three dimensional finite element method (3D FEM) analysis is carried out. The results obtained show that the existence of 3D shielding current in it determines the profile of toss properties under changing magnetic fields of face-on orientation, The effect of spatial period of the core structure along the cable axis on the loss is also elucidated, This will be a useful aid for the design of the cable.