Three-dimensional finite-element modelling of a superconducting suspension system

The suspension system considered is characterised by a superconducting magnet with an arrangement of superconducting screens to provide stable levitation of a long mild-steel bar [1]. This paper is concerned with static modelling of the magnetic forces for which a nonlinear three-dimensional analysis is required. Problems encountered using the magneto-static program TOSCA [2] are discussed and the code is subsequently extended to accommodate a representation of superconducting screens based on the critical-state model [3]. Measured and computed results which are in good agreement are presented, leading to further consideration of the practical application of the method.