Experimental and numerical studies of the effect of phase difference between transport current and perpendicular applied magnetic field on total ac loss in Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox tape.

The effect of phase difference between transport current and perpendicular applied magnetic field, Δφ, on total ac loss in multifilamentary, silver-sheathed (Bi,Pb)₂Sr₂Ca₂Cu₃O_x (Bi-2223) superconducting tapes was calculated numerically using Brandt’s equation [Phys. Rev. B 54, 4246 (1996)] and the results were compared with experimental results obtained by the calorimetric method. In the numerical calculations, the superconducting transition was modeled by E-J characteristics represented by a power law. The dependence of critical current density on the n value was taken into account. The dependence of critical current density and n value on applied magnetic field was obtained from experimental data. It was observed that Δφ has a significant effect on the loss behavior of Bi-2223 tapes and depends strongly on the relative values of transport current and applied magnetic field. The effects of Δφ on the individual components of transport loss and magnetization loss were also calculated. Good agreement between the calculated and experimental results is demonstrated. [ABSTRACT FROM AUTHOR]