托卡马克内部线圈由具有三层结构的套管导体绕制而成。在其加工过程中,可能会产生偏心缺陷,导致中间氧化镁陶瓷层绝缘性能下降,进而可能造成严重后果。因此,对其偏心缺陷进行有效的无损检测尤为重要。为提高涡流检测方法对于偏心缺陷的检测能力,降低提离变化等导致的误差,提出和验证了基于柔性涡流探头进行偏心检测的方法,并通过不同探头结构及放置方式下检出效果的对比,探讨了最优探头配置方式。

The conductor of ITER In-Vessel Coil (IVC) is of three-layer tubular structure. During manufacture procedure of IVCs, eccentricity may occur between the copper tube conductor and stainless-steel supporting tube. Large eccentricity may seriously reduce the insulation property of the middle ceramic layer of IVC conductor and cause big influence on the performance of entire IVC. Therefore, it is critical to evaluate the eccentricity of IVCs by using non-destructive testing techniques. Our group has proposed an eddy current testing method based on absolute pancake coil in earlier studies. To enhance the evaluation efficiency of the eddy current testing method and to improve evaluation precision, in this paper, ECT based on TR type flexible probe is proposed and its detect ability is demonstrated. In addition, optimized probe structure and arrangement are also investigated by comparing the detect ability of different probe structures.