A power source has been developed that generates various configurations of alternating-current oscillations of a given duration. The source current adds heat to a superconductor in small controlled portions, which allows studying dynamic processes on alternating current with amplitudes Ia exceeding the average critical values Ic. It is possible to predict the appearance of a narrow normal zone and determine the conditions for stable operation of the superconductor at Ia > Ic. On SuperOx superconducting tapes with a thin copper coating, the process of developing thermal instability up to the material burnout was observed.
Krasnoperov et al. (Mon,) studied this question.