POSSIBILITY OF REDUCTION IN HYSTERESIS LOSS DUE TO REVERSIBLE FLUXOIDMOTION IN A SUPERCONDUCTING BI-2223 MULTIFILAMENTARY WIRE

The energy loss density was measured and the AC penetration depth, lam bda(0)', was estimated from the slope of a minor magnetization curve f or a superconducting Bi-2223 multifilamentary tape at various temperat ures under the application of a parallel AC magnetic field to the tape . It was found that at high temperatures lambda(0)' was comparable to the filament thickness and the energy loss density was lower than that predicted using a modified Kim's model taking into account the effect of the diamagnetism. This reduction is ascribed to the reversible flu xoid motion inside pinning potential wells. The reduction of the filam ent thickness to less than 2 mu m is recommended for the achievement o f the low energy loss density at 77 K.