Reduction of alternating magnetic field losses in high-Tc multifilament Bi(2223)/Ag tapes by high resistive barriers

摘要

Flat High-Tc multifilament tapes with an Ag matrixhave very large coupling current losses in perpendicularly applied50 Hz magnetic fields. By the application of ceramic isolatingBaZrO_3- and SrZrO_3 barriers around the filaments we couldreduce at 77 K the coupling current decay time constant to 1.5 ms,leading to a significant loss reduction at 25 Hz and a noticeableloss reduction at 50 Hz. The coupling loss maximum for small ABvalues was shifted for a stack of six tapes to 110 Hz and for asingle tape to 180 Hz. By a further combined application ofseveral loss reduction measures the application of High-Tcsuperconductors in 50 Hz magnets will be possible in the next future.