Effect of Critical State Model on Magnetic Relaxation in Type-II Superconductors

Based on the theoretical model in which magnetic relaxation was considered, exact equations are derived for the relaxation rate, normalized relaxation rate and relaxation time. The relations between the theory on relaxation rate and experimental data are compared, as well as the relaxation time. The valid ranges of several models are specified and the magnitude of relaxation time is estimated. The results indicate that different models are suitable for different temperature regions and the effect of relaxation time on the experimental measurements could not be neglected.