Enhanced levitation force using YBa2Cu3Oy trapped field magnets

Levitation and stability forces have been studied using high-temperature su perconductor (HTS) trapped field magnets (TFMs) to replace the permanent ma gnets (PM) usually used. TFMs of YBa2Cu3Oy with maximum trapped field, B-TF M, UP to 1.6 T were used acid compared to a PM, with B-PM = 0.34 T at its s urface. The TFM or PM was opposed by a HTS cooled under various field cooli ng and zero field cooling conditions. It is found that the levitation force with the TFM can be increased by a factor of 10 or more. For example, for the TFM opposed by a saturated HTS with a maximum trapped field of 1.6 T, b oth 2 cm in diameter, the levitation force and pressure are F-L = 393 N; P- L = (125 N cm(-2)). The increase is limited only by B-TFM,B-max of the TFM used. Restoring forces do not increase quite as rapidly as levitation force s when PMs are replaced with TFMs. However, we find that both levitation an d stability forces can be significantly increased using multi-sample system s.