Speculations on multipaction. Speculations on multipaction. Any charged particle accelerated by the RF field can generate secondaries when it impacts the cavity surface.
Lightweight electrons damage the surface primarily by heating it.
The surface temperature can rise well above the ambient for the cavity wall as a whole. Surface mobility of atoms at the surface is enhanced at temperatures well below the melting point for the bulk material. Mobile charged surface atoms can move around under the influence on the local electric and magnetic RF fields. It is possible that ionic and electronic discharge damage can co-exist in the same component. It is speculated that the visual appearance of cavities damaged by ions will be noticeably different from those damaged by electrons.