A NONLINEAR MODEL OF SILVER-SHEATHED BI(2223) HIGH-TEMPERATURE SUPERCONDUCTING TAPE

The use of high temperature superconducting Ag sheathed Bi(2223) tapes as a component of a circuit requires a good understanding of their be havior in under-critical and upper-critical working conditions. We pro pose a modeling of such a device described by an inductance and non-li near resistors. Our model not only describes the AC behavior but repre sents more generally the dynamic behavior for frequencies below one hu ndred Hz and currents higher than the critical one. A special equivale nt circuit configuration is considered to take AC losses into account. The identification of the model parameters can be performed by the el ectrical measurement of sample tapes using a lock-in technique. Ag she athed Bi(2223) tapes are prepared by Professor Flukiger's team at the University of Geneva.