Effect of twisting on the filaments of multifilamentary BSCCO(2223)/Ag and /AgMg tapes

For reduced AC losses of multifilamentary BSCCO(2223) tapes, it is necesary to apply a twist to the filaments along the tape direction reducing the filament coupling losses, Twists with different twist pitches (10-80 mm) were realized in either Ag sheathed and mechanically reinforced AgMg sheathed 37 filament tapes, Possible reasons for the observed degradations of the transport critical current densities of 22 000 Acm(-2) (Ag sheath) and 19 000 Acm(-2) (AgMg sheath) down to 50% in the worst case (10 mm twist pitch) for twisted tapes, were investigated analyzing the influence of twisting on the conductor geometry and deformation via quantitative image processing of micrographs, The critical current I-C of differently twisted tapes was measured in a magnetic field for various tape orientations. From the J(C)(B) anisotropy the misalignement angle of the Bi(2223) phase texture was analyzed, and a comparison with rocking angles from X-ray experiments was performed.