Critical current anisotropy and AC losses in Bi(Pb)SrCaCuO-2223 and TlBaCaCuO-2212 Ag sheathed superconducting tapes

The dependence of the critical current as well as the AC self-field losses on the orientation of the external DC magnetic field of Bi(Pb)SrCaCuO-2223 and TlBaCaCuO-2212 Ag sheathed superconducting tapes prepared by the powder-in tube method was studied at 77 K. The self-field losses were measured using different voltage-tap configurations and different electrical measuring methods in the frequency range 5-400 Hz and superimposed DC magnetic fields up to 0.2 T. The emphasis has been laid on the field 0.05 T where B(Pb)SCCO samples exhibited a strong critical current anisotropy while TBCCO ones were practically isotropic. The interpretation of the experimental results is presented.