Equilibrium and propagation of the resistive-normal zone in AC superconducting composites

Equilibrium thermal cycles of ac conductors with a current sharing between a superconductor and a substrate are treated. During the propagation process a possibility of the coexistence of the superconducting and resistive zones or resistive and normal zones along the conductor is revealed. A possibility of the zone propagation process at the currents above the critical one is stated.