Magnetic Braking and Energy Loss in Contactless Bearings Based on Superconducting Tapes

We consider magnetic braking and energy loss appearing in contactless bearings based on high-temperature superconducting tapes. We analyze model configurations of bearings in which a superconducting tape is the stator, while the rotor is a set of permanent magnets. It is shown that magnetic friction can be ignored in the case when the number of permanent magnets in the rotor is greater than eight. This result indicates the possibility of designing scaled magnetic bearings for long-term energy storage systems (e.g., kinetic storage rings).