Reduction in AC transport self-field losses for Ag-sheathed Bi2223 tapes by changing filament arrangements using two-axial rollers

Without introduction of resistive barriers, we succeeded in reducing AC transport self-field losses at 77 K for Ag-sheathed Bi2223 multifilamentary tapes with the m×n (m,n=3, 5) filament arrangements, fabricated by a rectangular deformation process using passive two-axial rollers. In spite of the main contribution of hysteresis loss of superconductor, the transport losses for the samples are reduced by approximately 50-70% compared with the values for Ag-sheathed Bi2223 tapes by a standard powder-in-tube process. Further change in filament arrangements using two-axial rollers leads to a further reduction in the loss values. From numerical calculations, the loss reduction is mainly ascribed to a division of field-free-core under AC current transmission.