Giant dispersion of the critical currents in a superconductor with fractal clusters of the normal phase

The effect of the normal phase fractal clusters on the dynamics of the magnetic flux, captured in the superconductor, is considered. The distribution of the critical currents as well as the volt-ampere characteristics of the superconducting fractal structures for the arbitrary fractal dimensionality of the cluster boundaries are obtained. The range of the fractal dimensionality values, wherein the critical currents dispersion indefinitely increases, is identified. It is established, that fractality facilitates the reduction of the electrical field, originating by the magnetic flux motion and thus increasing the critical current value