Numerical modelling of Bi-2223 multifilamentary tapes with position-dependent Jc

Different measurement techniques have demonstrated that due to better alignment during the manufacturing process, the central filaments in multifilamentary Bi-2223 tapes have higher critical current density than the outer filaments. A numerical model of non-twisted tapes has been used in Finite-Element-Method simulations. The model incorporates non-uniform lateral Jc distribution in accordance with direct Ic measurements, made along the width of a Bi-2223 tape. Two types of simulations are performed on 7 and 19-filamentary tapes with applied transport current – one with constant Jc in all filaments, and another with a Jc(x) dependence. The current distribution and AC loss in each filament are numerically calculated and compared. It is demonstrated that the current density distribution and power dissipation vary considerably in the different filaments, which is due to the position of the filament with respect to the edge of the tape and the different Jc values along the width.