Dynamic response of Ag-Bi2223 tapes in applied fields by electric transport measurement

摘要

Electric transport measurement of Ag-sheathed Bi_(2-x)Pb_xSr_2Ca_2Cu_3O_y tapes inmagnetic fields H was conducted by the four-probemethod to study the effect of H and sweeping rate ofapplied current dl/dt on critical current. It is foundthat H and dI/dt apparently affect the critical currentand the V-I characteristic curve. To understand theexperimental result, numerical simulation was carriedout based on the collective creep model of the vortexglass. The numerical result is in agreementqualitatively with the experiment. It is shown that theinfluence of the applied field, temperature and vortexpinning on the normalized critical current can bereduced to a single critical current parameter n.