Kinetics of the destruction of superconductivity by a current less than Silsbee's critical value

An experimental study of the destruction of superconductivity in cylindrical tin wires by currents less than Silsbee's critical value is presented. The experiments show that in this case the average motion of the boundary between the superconducting and nonsuperconducting regions takes place longitudinally at a constant velocity. The conditions that must be fulfilled in order to observe this type of propagation are discussed, and calculations of the time required to start the transition and of the velocity of the boundary are given. (11 figures)