Magnetic interaction between multiple seeded YBCO bulks and the permanent magnet guideway

Abstract

Magnetic interaction between multiple seeded melt growth (MSMG) bulk YBCO and the permanent magnet guideway (PMG) has been investigated. There are two modes: parallel and perpendicular between the length directions of the PMG and MSMG bulks. We employ one piece of MSMG bulk and a stacked array consisting of three separated bulks in our experiments. They have similar dimensions and their maximum levitation forces are almost the same except for a slight difference in parallel mode. It is found that the MSMG bulk may be regarded as single larger grain bulk in the perpendicular mode due to inter-grain critical currents and it has much larger levitation force than the stacked bulk array. On the other hand guidance force of the MSMG bulk is larger than the stacked array in both parallel and perpendicular modes. In addition, its hysteresis loss becomes less in perpendicular mode. These indicate that MSMG bulk YBCO is preferable to optimize the present superconductor-PMG levitation system.