Finite element method study of the coupling effect between superconducting filaments in varying magnetic field

Using 3D finite element modelling, the present work investigates the coupling effect between superconducting filaments induced by an externally applied varying magnetic field. The considered geometry consists of two superconducting filaments separated by a resistive matrix. The shape of the conductors, which strongly influences the magnetic field profiles inside the conductors and the degree of coupling, has been varied to take into account very different cases: in particular, the slab, square and strip geometries have been considered for the cross-section of the superconducting filaments. The purpose of this work is to verify and extend the existing theory, which is only precise for superconductors of infinite slabs, fully penetrated by the magnetic field. The effect of other parameters such as the conductor length, the resistivity and the width of the normal metal between the filaments is also considered. The latter is a parameter which does not feature in the approximate theories.