A Study of Current Stability in the Dissipative Flux Flow State of Superconducting Films

In several superconducting applications, low energy losses are strictly demanding. In superconducting films, the dissipative flux flow state plays a role in the stability of the superconducting state in those devices that can operate just above the critical current (I_c). Therefore, details of the current-voltage (I- V) characteristics and in particular of current instabilities from the flux flow state to the normal one can become significant. We study current stability in the flux flow dissipative state by a proper current-voltage measurement mode. Low-temperature superconducting films have been investigated to demonstrate that the current stability range above I_c can be increased by light ion irradiation.