Lift and restoring force characteristics of a levitating X-Y transporter using high-temperature superconducting bulks

We have been investigating the electromagnetic behaviour of HTS bulks for realizing an X-Y (two-dimensional) magnetic levitating transporter without any fixed guides. The transporter is mainly composed of disc-shaped YBCO bulks and Nd-Fe-B permanent magnets or field-cooled YBCO bulks. The lower part and the upper part (levitating part) are magnetically connected. In such a 'levitating X-Y transporter', it is necessary to comprehend the characteristics, such as the lift, the levitation height and the stability against mechanical disturbances. In this paper, we evaluated the lift and the restoring force characteristics experimentally in the case where a field-cooled YBCO bulk is adopted instead of permanent magnets and also developed a numerical simulation program based on the finite element method to clarify the electromagnetic phenomenon in the HTS bulks