The Next Generation of Superconducting Permanent Magnets: The Flux Pumping Method
The Next Generation of Superconducting Permanent Magnets: The Flux Pumping Method
复制标题
下一代超导永磁体：磁通泵浦方法
DOI：
10.1109/tasc.2009.2018368
复制
发表时间：
2009
影响因子：
1.8
通讯作者：
C. Rawlings
中科院分区：
文献类型：
--
作者：
T. Coombs;Z. Hong;Y. Yan;C. Rawlings
由大块YBCO制成的磁体与稀土磁体一样小且一样紧凑，但潜在地具有比稀土磁体大几个数量级的磁通量密度。本文提出了一种简单的超导体磁化方法。这种技术涉及反复施加一个小磁场，这个磁场被超导体捕获，从而不断增强。因此，可以使用非常小的磁场（诸如可从稀土磁体获得的磁场）来产生非常大的磁场。该技术不使用移动部件，通过产生在超导体上移动的行波来实现。当它穿过超导体时，它会尾随在它后面的通量线，这些通量线会被超导体内部捕获。随着每一个连续的波，更多的通量线被捕获，磁场不断增强。波可以用许多不同的方法产生，但首选的方法是简单地加热一种材料，该材料的磁导率随其边缘的温度而变化。当热量穿过材料时，磁导率发生变化，产生磁波。它实际上是很长一段时间以来第一个新型热泵，它将使这些独特的、高度通用的超导磁体的巨大潜力得以充分实现。在本文中，我们提出的结果表明，超导体被逐步磁化的顺序施加ldquoheatrdquo脉冲。我们还表明，如果ldquocoldrdquo脉冲被施加，而不是热脉冲的磁化的符号被反转。这些实验结果得到了建模的支持。
Magnets made from bulk YBCO are as small and as compact as the rare earth magnets but potentially have magnetic flux densities orders of magnitude greater than those of the rare earths. In this paper a simple technique is proposed for magnetizing the superconductors. This technique involves repeatedly applying a small magnetic field which gets trapped in the superconductor and thus builds up and up. Thus a very small magnetic field such as one available from a rare earth magnet can be used to create a very large magnetic field. This technique which is applied using no moving parts is implemented by generating a traveling magnetic wave which moves across the superconductor. As it travels across the superconductor it trails flux lines behind it which get caught inside the superconductor. With each successive wave more flux lines get caught and the field builds up and up. The wave could be generated in many different ways but the preferred way is simply to heat a material whose permeability changes with temperature at its edge. As the heat travels across the material so the permeability changes and a magnetic wave is generated. It is in effect the first novel heat pump in a very long time and one which will enable the enormous potential available from these unique and highly versatile superconducting magnets to be fully realized. Within this paper we present results showing the superconductor being progressively magnetized by sequentially applied ldquoheatrdquo pulses. We also demonstrate that the sign of the magnetization is reversed if ldquocoldrdquo pulses are applied instead of heat pulses. These experimental results are supported by modeling.