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

The energy loss density was measured for a Bi-2223 tape wire with supercond ucting filaments of average thickness 2.5 mu m to confirm the reduction of energy loss density due to the reversible fluxoid motion. The energy loss d ensity is compared with the prediction by the modified Kim model. It is low er than the prediction at AC field amplitudes below the penetration field a t temperatures above 77 K. The slope of the minor magnetization curve is le ss than unity and the estimated AC penetration depth is longer than the fil ament thickness in the same regime. This result supports the speculation th at the reduction of the energy loss density is due to the reversible fluxoi d motion.