AC losses in multifilamentary Bi-2223/Ag superconducting tapes

In this study we examined AC losses in a multifilamentary Bi-2223/Ag superconducting tape carrying AC transport current. The tape consisting of 85 filaments was helically wound to a single-layer coil. The losses were measured at 77 K in the frequency range from 1 Hz up to 250 Hz. Current amplitudes I/sub p/ were ranging from l=I/sub p//I/sub c/=0.6 to 1.5, critical current I/sub c/=15.4 A determined by the standard 1 /spl mu/V/cm static electric field criterion. The roles of special loss components were considered: hysteresis, flux-creep, coupling and eddy current losses. Hysteresis losses due to the self-field of the AC transport current were found to dominate when l/spl les/1.1. Resistive losses dominated when l>1.2. In the hysteretic regime, the higher the frequency, the smaller the losses per cycle.