Load line analysis of Bi-2223 tape-stacked-cable for self field effects

In general, the critical current of a Bi-2223 tape-stacked-cable is much le ss than the total summation of critical currents of each tape, which is mai nly due to the self magnetic fields of the cable itself. Therefore, to pred ict the critical current of a Bi-2223 tape-stacked-cable, we need to analyz e the self field effects of the stacked cable as well as the critical curre nt density data (J(c)) of one tape. To make it more complex, the critical c urrent degradation of a Bi-2223 tape is aniotropic; the critical current is lower in the normal magnetic field (to the tape surface) than in the paral lel field. In this paper, a novel approach to predict the critical current of a Bi-2223 tape-stacked-cable from a J(c)-B curve of one tape is presente d. The approach basically includes the load line analysis of the stacked ta pes, and its usefulness is confirmed by the experimental data.