Levitation force between a small magnet and a superconducting sample of finite size in the Meissner state

The repulsion force between a cylindrical superconductor in the Meissner st ate and a small permanent magnet was calculated under the assumption that t he superconductor was formed by a continuous array of dipoles distributed i n the finite volume of the sample. After summing up the dipole-dipole inter actions with the magnet, we obtained analytical expressions for the levitat ion force as a function of the superconductor-magnet distance, radius and t hickness of the sample. We analyzed two configurations, with the magnet in a horizontal or vertical orientation. (C) 1999 Elsevier Science B.V. All ri ghts reserved.