The inductive method for measuring the critical current density j C and detecting the crack in a high-temperature superconducting (HTS) film have been investigated numerically. To this end, a numerical code has been developed for analyzing the shielding current density in the film with a crack. The results of computations show that the accuracy of the inductive method is degraded remarkably due to the crack. Specifically, it is found that, if the orthographic projection of the coil overlaps with the crack, the value of measured j C decreases. This is mainly because the spatial distribution of the shielding current density becomes asymmetry. In conclusion, the crack size and position can be accurately detected by measuring the j C-distribution in the HTS film.
展开▼
机译：数值研究了用于测量临界电流密度j C 并检测高温超导（HTS）膜中裂纹的感应方法。为此，已经开发了用于分析具有裂纹的膜中的屏蔽电流密度的数字代码。计算结果表明，归因于裂纹，归纳法的精度明显下降。具体地说，发现如果线圈的正投影与裂纹重叠，则测得的j C 的值减小。这主要是因为屏蔽电流密度的空间分布变得不对称。总之，通过测量HTS膜中的j C 分布可以准确地检测裂纹的大小和位置。
展开▼
