Helium migration in palladium I. Concentration dependence of helium release

Abstract
High temperature gas release from helium-implanted palladium has been investigated for He/Pd atom fractions from 5 × 10−6 to 5 × 10−2. The temperature required for 25 per cent He release increases with increasing dose to an atom fraction of 10−4, where a sudden reversal occurs for higher concentrations. The release is associated with dramatic changes in the surface features of the palladium. A qualitative physical model is presented to explain the data.