superconducting magnets

Superconductor science and technology/Superconductor science & technology

Contrary to the interaction between two magnets with opposite magnetizations directions, the interaction between a permanent magnet and a superconductor can be stable and result in magnetic levitation. This property can be exploited for the development of high velocity rotating bearings with no mechanical contacts and for the development of levitated trains. In this review, we focus on this last application. After a brief description of the other techniques developed for levitating trains and the resulting achievements, we describe the magnet-superconductor interaction and remind of the realizations achieved in this field. Then, we give insights on the properties of the employed magnets and arrangement of magnets and we detail the characteristics and the fabrication processes of the most frequently used superconductors. Focusing on physics, we detail the procedures generally used for measuring the vertical (levitation) and the lateral (guidance) forces in magnetic levitation and the results obtained from experiments. We detail and give a critical review of the various models proposed for reproducing the force measurements. In the conclusion we give insights on the possible future developments of the technology.

Superconducting magnetic levitation: principle, materials, physics and models