Vertical and lateral forces between a permanent magnet and a high-temperature superconductor
Vertical and lateral forces between a permanent magnet and a high-temperature superconductor
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DOI：
10.1063/1.371703
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发表时间：
1999-11
影响因子：
3.2
通讯作者：
J. Hull;A. Cansiz
中科院分区：
文献类型：
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作者：
J. Hull;A. Cansiz
测量了高温超导体（HTS）上方永磁体（PM）在零场冷却（ZFC）和场冷却（FC）条件下垂直和水平移动时所受的垂直和水平力及其刚度。在ZFC中，垂直刚度在第一次下降时大于在第一次上升和第二次下降时，并且在第二次下降时的刚度介于第一次下降和第一次上升之间。在FC位置，垂直刚度比每个高度的横向刚度大两倍，在垂直刚度值的1%以内。垂直力相对于侧位的横向刚度对于FC为正，而对于ZFC为负。还进行了悬浮在高温超导体上方的永磁体的自由旋转实验。这些结果表明，摩擦系数在转子共振频率以下是双值，这是由于PM/HTS相互作用中的交叉刚度造成的结果。冻结图像模型被用来计算。
The vertical and horizontal forces and associated stiffnesses on a permanent magnet (PM) above a high-temperature superconductor (HTS) were measured during vertical and horizontal traverses in zero-field cooling (ZFC) and in field cooling (FC). In ZFC, the vertical stiffness was greater in the first descent than in the first ascent and second descent, and the stiffness in the second descent was between those of the first descent and the first ascent. At the FC position, the vertical stiffness was two times greater than the lateral stiffness at each height, to within 1% of the vertical stiffness value. The cross stiffness of vertical force with respect to lateral position was positive for FC, but negative for ZFC. Free-spin-down experiments of a PM levitated above a HTS were also performed. These results showed that the coefficient of friction is double valued at frequencies just below the rotor resonance, a result attributed to cross stiffness in the PM/HTS interaction. A frozen-image model was used to ca...