Quantitative evaluation of perpendicular‐field losses in stacked high‐Tc superconducting tapes

The influence of stacks of Bi-2223 multifilamentary tape-shaped wires without twisting on AC losses observed in an external magnetic field perpendicular to their wide faces is investigated. The perpendicular-field losses decrease with increasing number of tapes in the range of small field amplitudes. At larger amplitudes, on the other hand, the AC losses have little dependence on the stack number. This can be attributed to the effect of magnetic interaction between wires. By taking into account effective demagnetization factors on the basis of theoretical consideration, the perpendicular-field losses are plotted on a master curve for the maximum magnetic field applied to the wires. Furthermore, the perpendicular-field losses measured as a function of the field amplitude are well reproduced by the numerical evaluation of AC losses for a slab with infinitely wide surfaces. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(3): 50–57, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10050