Cryocooler-cooled high T/sub c/ superconducting magnet excited by thermoelectromotive force
Cryocooler-cooled high T/sub c/ superconducting magnet excited by thermoelectromotive force
复制标题
低温冷却器冷却的高温/亚c/热电动势激励的超导磁体
DOI：
10.1109/tasc.2004.830522
复制
发表时间：
2004
影响因子：
1.8
通讯作者：
T. Okamura
中科院分区：
文献类型：
--
作者：
M. Ono;T. Kuriyama;A. Oguchi;J. Ueda;T. Okamura
本文介绍并分析了测试结果，以优化性能的新概念的低温冷却器冷却高温超导磁体，这是由热电动势激励。与传统的高温超导磁体相比，该磁体系统具有体积小、重量轻、可连续励磁等优点。也就是说，传统的HTS磁体不适合于在持续电流模式下操作，因为HTS线圈具有比LTS线圈大得多的通量流动阻力。因此，磁体需要外部电源来维持连续的磁场。因此，提出了通过热电元件的热电动势而不是外部电源来激励HTS磁体的概念。这种磁体系统将比传统的磁体系统更简单，因为它不需要大的外部电源。因此，该磁体适用于对空间和重量有严格限制的应用。在常规磁体中，连接到HTS线圈的电流引线被设计成使到线圈的热泄漏最小化。同样，对于由热电动势激励的新型磁体系统，热电元件的优化设计是必要的，以使漏热最小。利用低温制冷机对高温超导线圈和热电元件的冷端进行了冷却实验。实验测得采用Bi/sub 2/Te/sub 3/热电元件的新型磁体系统的漏热为0.22W/A。它是优化铜电流引线的两倍。
This paper presents and analyzes test results in order to optimize the performance of a new-concept cryocooler-cooled HTS magnet, which is excited by a thermal electromotive force. This magnet system has the advantages of compactness, lightweight and continuous excitation in comparison with conventional HTS magnets. That is, a conventional HTS magnet is not suitable for operation in persistent-current mode, because an HTS coil has much larger flux flow resistance than an LTS coil. So, the magnet needs an external power source to maintain continuous magnetic fields. Accordingly, the concept of the HTS magnet excited by a thermal electromotive force of a thermoelectric element instead of an external power source was proposed. This magnet system will be simpler than a conventional one because it doesn't need the large external power source. Therefore, this magnet is suitable for applications in which there are severe constraints on the space and the weight. In a conventional magnet, a current lead connected to the HTS coil is designed to minimize the heat leakage to the coil. In the same way, for the new magnet system excited by thermal electromotive force, the optimum design of thermoelectric element is necessary to minimize the heat leakage. An experiment in which the HTS coil and the cold junction of the thermoelectric element are cooled by a cryocooler has been carried out. The heat leakage of our new magnet system using of Bi/sub 2/Te/sub 3/ thermoelectric elements was found to be 0.22 W/A by experiment. It is twice as high as that for optimized Cu current leads.