Shielding current analysis in multiple-layered superconducting film with cracks: Application to contactless method for measuring jC

Applicability of the scanning permanent magnet method to the measurement of the critical current density in a high-temperature superconducting (HTS) film containing a crack with the consideration of a depth has been investigated numerically. To this end, a numerical code has been developed for analyzing the shielding current density in a multiple-layered HTS film with a crack. By using the code, the scanning permanent magnet method has been reproduced numerically. The results of computations show that a region including a crack can be obtained by using a defect parameter. In addition, it is found that the scanning permanent magnet method proved to detect the even internal crack.