Design, fabrication, and properties of magnetically compensated SSC strands

Nonsuperconducting saddle magnets can in principle be designed to produce an undistorted dipolar magnetic field, but if they are wound from superconducting strands, residual magnetization, MR, (i.e. persistent current) resident in the filaments causes a multipolar distortion of the desired field. Numerous ways of reducing this magnetization or its effect, at both the stand-design and magnet-design levels, have been proposed. In this paper the authors describe how the ferromagnetic compensator, in this case Ni, can be associated with the composite strand itself, either in the form of replacement filaments or as an electroplated coating on the outside surface