超导磁约束系统中超导磁体涡流损耗的研究

在超导磁约束系统中,超导磁体与射频场、磁场、声场、电场等复合场的兼容耦合是系统稳定运行的关键。探讨了在13.56 MHz频率下的Shoji型天线产生的高频电磁波对超导磁体的影响,高频电磁波会在超导磁体表面产生涡流损耗,进而产生功率损耗并生成热量,导致超导磁体失超。为避免失超现象的发生,在超导磁体室温孔内采用金属屏蔽层进行防护。利用COMSOL软件对整个电磁-射频非线性耦合场进行建模仿真分析,完成了屏蔽层结构的优化选择。基于计算结果,分析讨论了屏蔽层厚度和高度变化对超导磁体上涡流损耗功率的变化影响。通过对超导磁体涡流损耗功率随屏蔽层参数变化进行拟合,最终得到了优化后的屏蔽层参数。

Research on superconducting magnet eddy current loss in superconducting magnet confinement system

The compatible coupling of superconducting magnet with complex fields such as radio frequency field,sound field and electric field is important to the stability of superconducting magnet confinement system.This paper introduced the effect of high-frequency electromagnetic wave generated by Shoji antennas at 13.56 MHz on superconducting magnet.Electromagnetic wave would generate eddy current loss on the surface of the superconducting magnet,causing an increase of temperature and quench.In order to avoid the phenomenon of quenching,a metal electromagnetic shielding layer was used for protecting the superconducting magnet.In this paper,the electromagnetic-radio frequency nonlinear coupling fields were modeled and simulated by COMSOL software,and the optimization of the shield structure was designed.According to the results,the effect of the thickness and height variation of the shielding layer on the superconducting magnet eddy current loss power was analyzed.By fitting the eddy current loss power of the superconducting magnet with the variation of the shielding layer parameters,the optimized shielding layer was obtained.