Chemical effects on secondary photon and ion emission of ion bombarded beryllium, carbon and boron carbide surfaces

A study has been conducted to determine the effects of hydrogen and deuterium bombardment on the secondary photon and secondary ion emission properties of beryllium, which has been proposed as a material for a first-wall coating or a liner in tokamak reactor vacuum vessels. It is found that both the photon and ion emissions are strongly enhanced by hydrogen and deuterium bombardment. However, the unexpected intensity enhancements have proven, on closer examination, to be not the outcome of a direct chemical effect of the incident ions, but only an apparent enhancement resulting from surface oxide formation.