The effect of dose on the evolution of cavities in 500-keV 4He +-ion irradiated nickel

Abstract

Transmission electron microscopy has been used to investigate the effect of total dose on the depth distribution of cavities (voids or bubbles) in nickel irradiated at 500°C with 500-keV 4He + ions. A transverse sectioning technique, which allows one to obtain the entire depth distribution of cavities and of damage from a single specimen, was utilized. The size, number density and volume fraction of bubbles or voids were measured from the micrographs taken from samples sectioned parallel to the direction of the incident beam. The results for the dose range studied (2 × 10 19 to 1 × 10 21 ions/ m 2) show that the average cavity diameter, number density, and the volume fraction (i.e. swelling) increases with increasing dose. The peak in the swelling distribution occurs at depths 8 to 15% deeper than the peak in the calculated projected range profile.