AC Loss Characteristics of Ag-sheathed Bi-2223 Tapes in Transverse External Magnetic Field

摘要

AC loss characteristics of Ag-sheathed multi-filamentary Bi-2223 tapes in applied transverse magnetic fields have been evaluated at 77K. Both hy steresis loss and eddy current loss in fields to perpendicular to the tape surface were much larger than those in parallel fields. The frequency dependence of AC losses of the twisted tape with 8.6mm pitch was similar to that of the untwisted tape in a perpendicular field of 29mT and frequency 40-400Hz. On the other hand, AC loss in a parallel field decreased with reductions in the sample length or the twist pitch; this shows that the electromagnetic filament coupling was partly suppressed by twisting.