It was found that radiation damage arose from electron beams with energies that were much lower than the threshold that was normally required, in compounds, for the knock-on of O ions. Finite-element methods were used to simulate thermal and charge effects in the superconducting film and substrate. The calculations showed that interstitials, under electric and thermal field gradients, drifted away from the beam during damage and that diffusion-induced equilibrium was inhibited by the relatively rapid temperature decrease that occurred upon moving the beam.

A.J.Bourdillon, N.X.Tan: Superconductor Science and Technology, 1995, 8[7], 507-12