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This paper describes the numerical results of AC losses in various types of non-twisted multifilamentary tapes that actual Bi-2223 Ag-sheathed wires are idealized. The penetration process of magnetic flux into the superconductor filaments subject to Bean's critical state model is simulated for the application of an external transverse magnetic field perpendicular to the broadest face of tape wire by means of energy minimization. The AC losses under cyclic fields are calculated from the distribution of a vector potential in an initial state. The influences of arrangements and shapes of the filaments on the losses are investigated as compared with those for a wire that the entire filamentary region is regarded as a homogeneous superconductor. [ABSTRACT FROM AUTHOR]

AC losses are numerically estimated in straight superconductors with an elliptic cross section exposed to a transverse magnetic field. It is assumed that the distribution of magnetic field in the superconductors is determined by Bean's critical state model, in which the critical current density is independent of the magnitude of local magnetic field. The penetration process of magnetic flux into the superconductors approximated as a group of fine rectangular bars is evaluated by means of the minimization of magnetic energy for the application of the external magnetic fields with arbitrary angles to their broadest face. By using the obtained penetration process, the AC losses are also calculated from the distribution of magnetic vector potential inside the superconductors. Furthermore, the compensation for the numerical results of AC losses enables us to obtain a universal loss property that is scarcely affected by the aspect ratio of cross section and the angle of external field. [ABSTRACT FROM AUTHOR]

Abstract: Analytical expressions of alternating current (AC) losses are derived in a superconducting wire with an infinite length and elliptic cross-section for limiting cases in which the amplitude of an external transverse magnetic field is much smaller or larger than the full penetration field. Since it is assumed that the superconducting wire is subject to Bean’s critical state model, in which the critical current density is independent of the magnitude of the local magnetic field, the AC losses under consideration are completely hysteretic. The expressions obtained explicitly include the effects of the aspect ratio of the wire cross-section and the external-field angle with respect to the broadest face. An approximated curve of the AC loss, which becomes equal to the analytical results under the limiting conditions mentioned above, is also proposed for a wide range of external-field amplitudes. In order to validate the proposed curve, the AC losses in the elliptic wires are numerically calculated by means of the minimization of magnetic energy. It is concluded that the discrepancy between the approximated curves and the numerical results of the AC losses is less than 40%. [Copyright &y& Elsevier]