Measurement of relation between current applying time and trigger current level of Y123 thin film for sinusoidal current

The voltage - current characteristics of Y123 thin film have been measured by use of sinusoidal currents of various frequencies and amplitudes. As a result, relation between the operational current at which the Y123 thin film changes its state from superconductive to normal conductive and frequency of the current has been obtained. The relation between operational current and frequency is discussed by considering the heat generation and transfer. It is shown that the heat transfer to the coolant is an important factor that determines operational current of a certain frequency.