Contactless Verification of the Defects in 2G HTSC Tapes With Two-Side Superconducting Layers

One way of increasing the critical current of high-temperature superconducting (HTSC) tapes is manufacturing tapes with two superconducting layers on the opposite sides of a metallic substrate. Traditional methods of defect control like scanning Hall probe measurements do not allow to separate the signals from each of superconductor sides and, as a consequence, to control the quality of the different superconducting layers. To solve this problem, we present a new method for magnetometric diagnostic of cracks and sharp localized defects in HTSC tapes with two-side superconductive layers. Using the presented method, it is possible to find the defects' location on each side of the tape. For realization of the method, it is needed 1) to measure magnetic field distribution over each side of the tape; and 2) to use a specially developed numerical algorithm. The experimental application of this method for testing the simulated tape derived from two separate one-sided HTSC tapes shows a possibility of determination of cracks position in the superconducting layers. This paper will focus on detail description of the method and discussion of obtained results.