Electromechanical stresses in superconductors: An analysis using the critical state model

An analysis of the electromagnetic stresses on a hard superconductor wire has been performed by the critical state model. A theoretical approach has been carried out by taking into account both the field produced by the current flowing in the wire and an external field orthogonal to the wire axis. Owing to analytical difficulties, mainly depending on the non-linear hysteretical feature of the field penetration, a general solution cannot be found. Nevertheless, under some restrictive conditions, an approximate solution is obtained, allowing us to compare the various force components of different origin acting on the wire.