Numerical calculation of critical current in Bi-2223 stacked tapes

As we stack HTS tapes, the critical current of stacked tapes is much less t han the total summation of the critical current of each tape. This is mainl y due to self magnetic field effects, and its behavior has been analyzed by load line or numerical methods with some assumptions. In this paper, we pr opose a simple numerical model to calculate the critical current of stacked tapes more exactly, To do this, we measured J(c)-B curves of a HTS tape fo r various values of external magnetic fields and the angles between the mag netic field and the tape surface, Using this experimental data, the current density distribution in the cross section of stacked tapes is calculated n umerically and the results are compared to both experimental values and the ones from load line analysis method, calculated simply by assuming uniform current density across the tapes.