Levitation force and stability of superconducting linear bearings using NdFeB and ferrite magnets

In the frame of a project on the development of a reduced-scale-levitating rail-vehicle prototype, the performance of two different permanent magnets have been tested in linear bearings using YBa2Cu3O<f>7−y</f> bulk superconductors. The levitation forces, the stiffness and the vibration damping have been measured using two different rail assemblies: one mounted with NdFeB magnets and another with ferrite ones. The levitation force of the NdFeB rail is more than one order of magnitude larger than that of the ferrite one. The stiffness of those linear bearing and the vibration damping were measured for several cooling heights from the rail. The stiffness increases with the decrease of the cooling height and is larger in the NdFeB rail. The vibration damping is rather low in both systems. Finally, we conclude that the NdFeB magnets are the most suitable for applications on linear levitating bearings. [Copyright &y& Elsevier]