Effects of complex processings on critical current density of Bi-2223 tapes

Some long-length Bi(Pb)-2223 tapes produced using the PIT technique and multilayered structure technique have been developed for an industrial material for which the requirement is the J_c = 30 kA cm^-2 class at 77.3 K in long-length wires. For this purpose, we have achieved recent progress in performance, such as reproducibility of the J_c = 20 kA cm^-2 class at 77.3 K and low magnetic fields for long-length tapes having sound filaments, overall critical current density of 10 kA cm^-2 in a low silver:superconductor ratio tape, allowable strength of more than 100 MPa using silver alloy sheath and low AC loss of less than 0.3 W kA^-1 m^-1 in kA class conductors using twisted wires.