Surface plasmon de-excitation of multiply charged ions

Electrons in excited states of a multiply charged ion have traditionally been viewed as decaying through Auger processes. Competing with this is photon emission and decay through excitation of the surface plasmon of a solid. The latter is very effective in the energy range 10-30 eV. Utilising part of the available neutralisation energy it leads to a reduction in the number of ejected Auger electrons. For larger energies the photon emission dominates all the other processes.