Suspension Experiments Using Flux Pinning

Abstract

There are two methods that cool superconductors to liquid nitrogen temperature: zero-field cooling (ZFC) and field-cooling (FC). The ZFC superconductors can be levitated high above the magnet because they have a strong repulsive force of perfect diamagnetism. On the other hand, FC superconductors have not only a repulsive force but also an attractive force for magnets. This chapters introduce various superconducting suspension experiments using FC superconductors. This phenomenon is known as the suspension effect or the fishing effect. Descriptions are given of the levitation of a superconductor above a single magnet, the simultaneous levitation of a superconductor and a magnet, the suspension of superconductors next to a magnet, suspension experiment using a glass cup or measuring cup and superconductor trapped in a ring-shaped magnet.