Self-stable suspended rotors utilizing superconducting niobium

Total masses in excess of 0.150 kg were very stably suspended using trapped flux and subsequent screening currents associated with a superconducting disk 25.4 mm in diameter by 7.18 mm thick acting on a 25.4 mm diameter by 9.79 mm thick rare earth magnet. Such suspended masses can be rotors, optical elements, etc., with numerous applications. Both lateral and vertical forces as a function of displacement for a fixed, previously trapped, flux are described. Observed small drag losses on a high speed rotor are presently attributed to air resistance and eddy currents in the cryostat walls instead of flux motion in the niobium. Hall probe mapping of the fields, small asymmetries in the fields, and hardware limitations and means of improvement are described, along with other details