Measurement of critical current and transient characteristics of a high-temperature superconductor tube with a pulsed current supply

The transient response of a melt-cast-processed BSCCO-2212 superconductor tube was investigated by using a pulsed current supply, it was found that (a) the maximum induced current and the excitation current at field penetration increase with the maximum excitation current, and (b) there is a time delay between peak excitation current and peak magnetic field inside the superconductor. These observations can be explained by magnetic diffusion. The AC steady-state critical current of the superconductor was found to compare favorably with that of the pulsed current test when the excitation current is relatively low, but it falls below that of the pulsed current test when the excitation current is relatively high.