Nonequilibrium States in HTS Tapes under the Action of Short Current Pulses

Resumo

This paper presents the results of studying the nonequilibrium processes in second generation HTS tapes under the action of pulsed current loads. In the study, we used short current pulses of various amplitudes from 0.9 to 5 values of the superconductor critical current. The minimum rise time of the current was 8 µs, and the pulse duration was from 1 to 250 µs. Comparisons in the behavior of samples under long current pulses with current rise time more than 3 ms were carried out. A qualitative difference in the formation of an nonequilibrium state during short and long current pulses was found. A stable current flow with amplitudes up to 4 times larger than the critical current was obtained without degradation of the superconductor. Experimental results were analyzed on the basis of the dynamic resistance model in the flux flow regime.