NON LINEAR EFFECTS IN ION INDUCED ELECTRON EMISSION

High-resolution zero-degree electron spectra, total electron yields as well as Auger-electron spectra have been taken for 5 MeV/u ions (N7+, S13+, Ni23+, and Ag37+) penetrating carbon and insulator foils at normal incidence. A shift of the convoy-electron velocity with respect to the experimentally determined projectile velocity is found. For the carbon target, there is an acceleration of convoy electrons, whereas for the insulating targets, there is a deceleration of convoy-electrons as well as a deceleration of target-Auger electrons. These experimental findings are compared to theoretical estimates for dynamic ion-induced potentials. Key Words: Electron yields, Auger spectra, convoy electrons, non-linear effects, nuclear-track potential, electron recombination, image potential, Coulomb explosion. *Address for correspondence