Secondary ion emission from stainless steel and inconel due to hydrogen ion bombardment

Secondary ion emission from stainless steel 304 and inconel 625 resulting from the impact of H +, H 2 +, and H 3 + at 5 keV is studied and secondary ion energy distributions for Fe +, Cr +, Ni +, CrOH + and FeOH + are reported. For the metallic bulk ions, the energy distribution, N +( E), is described by the random collision cascade model modified by the probability of charge transfer in the surface region: N +( E) = CE n+1 ( E + E b ) −3, where E b is the sublimation energy, and n describes the charge transfer in the surface region. This model does not describe N +( E) for the hydroxyl ions or for the metallic bulk ions at non-normal emission from a heavily contaminated surface. The results are also discussed with reference to magnetic fusion energy devices.