Electron irradiation effects in lead-alloy Josephson junctions

Abstract

Electron irradiation was performed on lead-alloy Josephson junctions with incident electron energies of 15 keV to 3.0 MeV. The quasi-particle tunneling current was observed to increase, proportional to the electron fluence over the range (1015∼1018 electrons/cm2). Radiation effects at low energy (≤30 keV) clearly indicate that radiation-induced point defects within the tunnel barrier are responsible for changes in both the tunneling current and the annealing characteristics of junctions.