Non-destructive evaluation of critical current on a Bi-2212 first stage cable based on numerical analysis of the remnant field distributions

The high temperature superconducting material Bi-2212 is considered for use in the next generation of fusion reactors due to an excellent current carrying capacity in a high field. The critical current as well as its inhomogeneity are important factors in evaluating the performance of Bi-2212 wires, cables and conductors. Non-destructive evaluation by using a Hall sensor array is a more effective and faster method for testing the local critical current of a high temperature superconductor compared with a conventional contact-electrical method. In this paper, the coupling and decoupling numerical models of the perpendicular component of the residual magnetic field in Bi-2212 round wire were solved. Then, the perpendicular component of the remnant magnetic field was measured by a Hall sensor array, which was consistent with the results of the coupling model. Our results established the numerical model for a Bi-2212 first stage cable and found that the non-destructive method using four mutual vertical Hall sensor arrays is feasible for evaluation of cable critical current properties.