Radiation Blistering After H⁺, D⁺, and He⁺ Ion Implantation into Surfaces of Stainless Steel, Mo, and Be

Abstract

H⁺, D⁺, and He⁺ ions with energies of 15 and 150 keV were implanted into surfaces of stainless steel, Mo, and Be. The occurrence of blisters has been observed by scanning electron microscopy and by optical interference microscopy.

In all investigated metals severe blistering was observed after He irradiation to fluences above 3 × 10¹⁷ ions/cm².

On H⁺ and D⁺ bombarded stainless steel irregular shaped blisters were observed mainly at special sites such as grain boundaries and precipitations. The critical fluence for blister formation by 15 keV D⁺ ions was in the order of 5 × l0¹⁸/cm².

For polycrystalline Mo the shape and the average size of hydrogen blisters depends strongly on the pretreatment of the targets. For annealed targets the blister size is much smaller than for unannealed material. The shape and the critical fluence depend strongly on the orientation of individual grains. The critical fluence, defined as the value at which blisters are first observed in some grains, decreases with increasing current density of the bombarding particles.

On D⁺ bombarded Be, blisters occurred at fluences below 3 • 10¹⁷ ions/cm².