托卡马克内部线圈导体偏心缺陷涡流检测探头参数优化

Parameter Opitimization of Eddy Current Testing Probe for Evaluation of Eccentricity in Conductors of Tokamak In-Vessel Coils

针对托卡马克内部线圈导体在加工过程中可能会产生偏心缺陷,导致中间陶瓷层绝缘效果降低的问题,通过不同结构柔性涡流探头及各种放置方式下检出效果的对比,分析了探头优化配置方式。为进一步提高检出灵敏度,基于退化磁矢位(Ar)方法进行了数值计算,探讨了不同尺寸参数的柔性探头对检出效果的影响,对探头尺寸参数进行了优化,为实际检出时涡流探头的设计提供了理论依据。

During manufacture procedure of IVCs,eccentricity may occur between the inner and outer tubes.Large eccentricity could seriously reduce the insulation property of the middle ceramic layer of IVC conductor and weaken the performance of entire IVC.Therefore,it is necessary to evaluate the eccentricity of IVCs by using nondestructive testing techniques.An eddy current testing method based on flexible probe had been proposed in early studies of authors.To enhance the sensitivity of the eddy current testing method further,in this paper,a numerical simulation was performed based on the reduced magnetic vector potential method（Ar）to investigate the influence of probe size on the testing sensitivity.Simulation results clarified the optimized parameters of flexible probe,and provide a theoretical basis for the design of flexible probe for practical application.