Residual Fields in Superconducting Dipole and Quadrupole Magnets
Residual Fields in Superconducting Dipole and Quadrupole Magnets
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超导偶极和四极磁体中的残余磁场
DOI：
10.1109/tns.1971.4326146
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发表时间：
1971
期刊：
影响因子：
--
通讯作者：
M. Green
中科院分区：
文献类型：
--
作者：
M. Green
本文讨论了超导二极和四极磁体剩余场的磁测量。本文描述了用于测量残余场的技术。测量的结果，并与一个简化的理论，预测剩余领域的基本性质进行了比较。尽管在理论中作了简化的假设，但理论和实验相当吻合。在超导磁体中产生的剩余场确实影响在这样的磁体中产生的场的均匀性。在超导同步加速器中，低场是最理想的磁场均匀性区域，而低场的影响最大。该理论表明，可以通过以下方式降低幅度：（1）减小材料中的股线直径（较小的股线需要更多的扭曲以消除耦合）;以及（2）降低材料的低场临界电流，这也降低了交流损耗和不稳定性。该理论还表明，注入感应低至1千克的超导同步加速器必须有超导股小至1至2？M.
This paper discusses the magnetic measurements of residual field in superconducting dipole and quadrupole magnets. The technique used to measure residual fields is described herein. The results of the measurement are presented and compared with a simplified theory, which predicts the basic nature of residual fields. The theory and experiment agree reasonably well despite the simplifying assumptions made in the theory. The residual fields generated in a superconducting magnet do affect the uniformity of the field generated in such a magnet. The effects of residual field are worst at low field, which is precisely where one wants the most magnet uniformity in a superconducting synchrotron. The theory suggests that one can reduce the magnitude by: (1) reducing the strand diameter in the material (smaller strands require more twist to eliminate coupling); and (2) reducing the low-field critical current of the material, which also reduces ac loss and instabilities. The theory also suggests that superconducting synchrotrons with injection inductions as low as 1 kG must have superconductor strands as small as 1 to 2 ?m.