Bulk large-grain superconductors can be used as high-field permanent magnets. Although the properties of such individual trapped field magnets are well documented, much less is known concerning their behaviour when two are brought together. In this work, the interaction between two cylindrical bulk YBa2Cu3O7 (YBCO) superconductors is described. Two sets of experiments were carried out. The first set of experiments involved the simultaneous magnetization of two bulk superconductors placed a short distance apart. The applied magnetic field was aligned parallel to the c-axis of one bulk, while the other had its c-axis directed at different angles. For a centre-to-centre distance equal to twice the sample height, the presence of the second sample is found not to alter the current distribution inside the first. Consequently, the contribution of both samples simply sums, thus increasing the magnetic flux density between them. In the second set of experiments, the translational approach of the superconductors with parallel c-axes was investigated. The following configurations were considered: (i) face to face approach (with anti-parallel trapped field orientation) and (ii) sideways approach (with parallel trapped field orientation). An irreversible decrease of the trapped field was measured when the samples are separated again. Repeated approach cycles showed that the irreversible loss of trapped field is most significant for the first approach.

中文翻译：

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两个彼此靠近的磁化体超导体上方的俘获磁场分布

块状大晶粒超导体可用作高场永磁体。尽管这些单独的俘获场磁体的特性已被很好地记录在案，但当两者结合在一起时，关于它们的行为却知之甚少。在这项工作中，描述了两个圆柱形块状 YBa2Cu3O7 (YBCO) 超导体之间的相互作用。进行了两组实验。第一组实验涉及两个相隔很短距离的块状超导体的同时磁​​化。施加的磁场平行于一个块体的 c 轴排列，而另一个块体的 c 轴指向不同的角度。对于等于样本高度两倍的中心到中心距离，发现第二个样本的存在不会改变第一个内部的电流分布。最后，两个样本的贡献简单地相加，从而增加了它们之间的磁通密度。在第二组实验中，研究了具有平行 c 轴的超导体的平移方法。考虑了以下配置：（i）面对面的方法（具有反平行的陷阱场方向）和（ii）侧向的方法（具有平行的陷阱场方向）。当再次分离样品时，测量到俘获场的不可逆减小。重复的进场周期表明，第一个进场的圈闭场的不可逆损失最为显着。考虑了以下配置：（i）面对面的方法（具有反平行的陷阱场方向）和（ii）侧向的方法（具有平行的陷阱场方向）。当再次分离样品时，测量到俘获场的不可逆减小。重复的进场周期表明，第一个进场的圈闭场的不可逆损失最为显着。考虑了以下配置：（i）面对面的方法（具有反平行的陷阱场方向）和（ii）侧向的方法（具有平行的陷阱场方向）。当再次分离样品时，测量到俘获场的不可逆减小。重复的进场周期表明，第一个进场的圈闭场的不可逆损失最为显着。