MAGNETIC-LEVITATION USING PERMANENT-MAGNE TS WITH HIGH CRITICAL-TEMPERATURE SUPERCONDUCTORS

Since their discovery in the years 1986/87, the high critical temperat ure superconductors have reached nowadays performances interesting eno ugh to conceive passive magnetic bearings and suspensions which would combined permanent magnets and naturally stable superconducting pellet s. After underlining the principal factors that affect the superconduc tor-magnet interaction, different experimental results are given about vertical and axial forces with some stiffness values. The magnetizati on curve of a superconductor help to understand the hysteretic behavio r of the force as a function of the distance between superconductor an d magnet. So called simple and hybrid structures of superconducting ma gnetic suspension are presented. Finally simple numerical simulations allow to draw some interesting conclusions about both geometry and bes t fitting structure of permanent magnets.