通过对方形永磁体和方形辅助永磁体在液氮温度下对GdBCO超导体磁化后超导磁悬浮力的测量,研究了两种组态中方形辅助永磁体对超导体的磁化方式对单畴GdBCO超导块材磁场分布及其磁悬浮力的影响.结果发现,方形辅助永磁体的下表面和超导体上表面保持在同一个水平面上,磁化进程中方形辅助永磁体在GdBCO超导体上表面水平面内沿直径方向的位置x从?15 mm增加到+15 mm时,超导磁悬浮力大小与超导体的磁化方式有着密切关系(以Z=0.1 mm为例):1)当方形辅助永磁体N极垂直向上且场冷后去掉辅助永磁体时,超导体最大磁悬浮力先从16.7 N增大到23.1 N,再减小到16.6 N;2)当方形辅助永磁体N极垂直向下且场冷后去掉辅助永磁体时,超导体最大磁悬浮力先从17.7 N减小到7 N,再增加到17.6 N;3)两种组态中最大磁悬浮力不相等,而且与零场冷下的最大磁悬浮力(17.1 N)也不同.这些结果说明:只有通过科学合理地设计超导体和永磁体的组合方式,才能获得较高的磁场强度,有效地提高超导体的磁悬浮力特性,该结果对促进超导体的应用具有重要的指导意义.
It has been investigated that the interaction force between a cubic permanent magnet PM1 and a GdBCO bulk (HTSC) super-conducting permanent magnet (SCPM) magnetized by a cubic permanent magnet PM2 under different configurations at 77 K. Two configurations were used for the magnetization of the GdBCO bulk, one is that the North pole of the PM2 is in upward direction, the other is in downward direction, so that the North pole of the SCPM is in two states SCPM↑and SCPM↓;the vertical distance between the bottom surface of PM1 and the top surface of SCPM is kept as a constant value, but the PM2 can be fixed at any positions (x) along a diameter of the GdBCO bulk during the magnetization process. It is found that:for the PM1↓-SCPM↑configuration, the maximum levitation force is increasing from 16.7 N to 23.1 N when x increases from?15 mm to 0, and then decreases to 16.6 N when x further increases to 15 mm;but for the PM1↓-SCPM↓configuration, the maximum levitation force is decreasing from 17.7 N to 7 N when x increases from?15 mm to 0, and then increases to 17.6 N when x further increases to 15 mm. These results are not only much different in the two configurations, but also much different from the maximum levitation force 17.1 N of the sample under zero field cooled condition, which is closely related with the trapped field distribution of the SCPM at different x values. These results indicate that the levitation force of high temperature bulk superconductors can be effectively improved by introducing additional permanent magnet based on scientific and reasonable designing of the system configurations, which is very important during the practical design and applications of superconducting magnetic levitation systems.