Magnetic flux shielding in superconducting strip arrays

Meissner shielding in arrays composed of parallel diamagnetic strips has been studied when the field is applied normally to the wide face of strips. The numerical solution of the Laplace equation has been found using a commercially available finite-element code for electrical and magnetic analysis. First, the code application has been tested on simple structures such as a single ellipsoid or rectangular strip in a transverse field. Then, a regular two-dimensional array of parallel strips has been considered. The results of the computation can be approximated by simple empirical formulas for the magnetic susceptibility of such an array. As the last step, typical filament configurations of two real BiSrCaCuO-2223 multifilamentary tapes have been studied and the susceptibilities in the Meissner state calculated. We found that the regularity in filament distribution can dramatically influence the magnetic properties and consequently the magnetic ac losses in the tape.