Effect of reciprocating motions around working points on levitation force of superconductor-magnet system. (September 2016)

• Record Type: Journal Article
• Authors: Xu, Jimin; Zhang, Fei; Sun, Tao; Yuan, Xiaoyang; Zhang, Cuiping
• Is Part Of: Cryogenics. Volume 78(2016)
• Page Start: 96
• Page End: 102
• Publication Date: 2016-09
• Subjects: Superconductor-magnet system -- Reciprocating motions -- Grain orientations -- Levitation force -- Vortex dynamic; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2016.07.010
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: Two YBCO samples with different grain orientations are used for the experiments. Practical vibration around working points are simulated by reciprocating motions. The initial cooling processes include ZFC and FC. Reciprocating can suppress time-decay in ZFC and FC levitation force. A stable redistribution of flux lines can be achieved gradually after reciprocating. Abstract: In order to simulate vibration around working points in practical operation of superconducting levitation system, magnet in a simple superconductor-magnet system are conducted reciprocating motions around static height in this study. Two YBCO cylindrical samples with different grain orientations are used to investigate the effect of reciprocating motions of magnet on superconducting magnetic force. The c -axis of sample S1 is perpendicular to the top surface while sample S2 is parallel to the top surface. The initial cooling processes for the superconductors include zero-field-cooled (ZFC) and filed-cooled (FC). Compared to the levitation force before reciprocating motions, the ZFC levitation force at static height becomes smaller after reciprocating while the FC force presents opposite phenomenon. It is found that levitation force at static height tends to be stable after several times of reciprocating under ZFC and FC conditions and its time-decay phenomenon is suppressed in some extent, which is meaningful for the practical application of superconducting levitation system. Based on vortex dynamic, some physical discussions are presented to the experimental results.