A progress in reducing AC transport losses of Ag-sheathed Bi2223 tapes by a rectangular deformation using two-axial rollers

Abstract Significant reduction in AC transport losses at 77 K and self-field has been achieved for Ag-sheathed Bi2223 multifilamentary tapes with the m × n ( m , n =3 or 5) filament arrangements, which were fabricated by a rectangular deformation process using passive two-axial rollers without any resistive barriers. Despite the main contribution of the hysteresis loss of superconductor, the transport losses for the samples are reduced by approximately 50–70% compared with those for Ag-sheathed Bi2223 tapes by a standard powder-in-tube process. More complicated filament arrangements by a rectangular deformation process lead to a further reduction in the loss values. Numerical calculations show that the loss reduction mainly results from a division of field-free-core under AC current transmission.