Calculation of magnetic levitation/suspension force of single grained Y-Ba-Cu-O superconductors

Top-seeded single-grained YBCO samples capable of levitating or suspending over kilograms of weight Lye been measured. However, the detailed relations hip of the levitation or suspension forces between permanent magnets and si ngle grained superconductor samples have not been fully studied, which is r equired to design a large scale system. In this report, an empirical method was used to calculate the levitation/suspension force. First, the magnetic field of the permanent magnet and the superconductor was measured by a Hai l probe, which was mounted on a x-y stage. The corresponding circulating cu rrent, which results in the measured magnetic field distribution, could the refore be calculated. The force between these two sets of current distribut ions at various distances was calculated and compared with measured levitat ion/suspension forces. Good degree of agreement between the measured and ca lculated suspension/levitation force was achieved by this empirical method.