Hysteresis loss in a superconducting Bi-2223 tape with fine filaments

The energy loss density was measured for a Bi-2223 tape wire with superconducting filaments of average thickness 2.5 /spl mu/m to confirm the reduction of energy loss density due to the reversible fluxoid motion. The energy loss density is compared with the prediction by the modified Kim model. It is lower than the prediction at AC field amplitudes below the penetration field at temperatures above 77 K. The slope of the minor magnetization curve is less than unity and the estimated AC penetration depth is longer than the filament thickness in the same regime. This result supports the speculation that the reduction of the energy loss density is due to the reversible fluxoid motion.