Influence of cross-sectional geometry and lateral Jc distribution on AC transport losses of Ag-sheathed Bi-2223 tapes

Abstract

We investigated the influence of cross-sectional geometry and lateral critical current density ( J c) distributions on the AC transport self-field losses at 77 K for the Ag-sheathed (Bi,Pb)-2223 multifilamentary tapes. The modified powder-in-tube method composed of a rectangular deformation and an ordinary rolling process was applied to prepare tapes with different filament arrangements. The trapped magnetic field profiles on the tape wide face in a remanent state indicate that J c distributions along a width direction of the cross-section are strongly influenced by the filament arrangement in each tape. The measured AC transport losses show significant dependence on the filament arrangement, although the main contribution to the losses comes from the hysteresis loss in superconductor filaments. This is caused by the shape of field-free-core and flux-penetration regions, varying with filament arrangement and non-uniformity of J c values along the width direction.