The Appearance Mechanism of Two-Dimensional Stability ofthe Mixed-μ Magnetic Levitation System

Abstract

Mixed-μ system of levitation consists of a magnetic flux source and materials of both μ>μ₀ and μ<μ₀, for example permanent magnet, iron and high-temperature bulk superconductors. Because of the diamagnetism of bulk superconductors located between the permanent magnet and iron, two-dimensional stability is realized without active control. We have already calculated the levitation and guidance characteristics using the two-dimensional FEM (finite element method). However it is difficult to obtain the optimum sizes of each elements and gap length.
In this paper the relation of the two-dimensional stability of three components, i.e. permanent magnets, iron and high-temperature bulk superconductors, of the mixed-μ system is found. And the appearance mechanism of two-dimensional stability is explained. It reveals that the relative position of the corner of the iron with respect to the one of the superconductor determines the two-dimensional stability.