Abstract
We fabricated twisted Bi2223 tapes with interfilamentary oxide barriers and evaluated their AC loss properties in an AC perpendicular magnetic field. The conventional powder-in-tube method was used for tape fabrication. In order to avoid the side effect on Bi2223 phase formation, SrZrO3 was selected for barrier materials. In addition, 20wt% Bi2212 was mixed with SrZrO3 to improve its ductility for cold working. Monocore Ag-sheathed rods were dip-coated by the oxide barriers with slurry before stacking with multifilamentary structures. By applying both the tight twisting with twist pitch length below 10 mm and introducing SrZrO3 + Bi2212 barriers, the coupling frequency in a perpendicular field was increased above 100 Hz and perpendicular field losses were reduced from the analytical prediction for fully coupled filaments around power-grid frequency range.
