Near-threshold behavior of the 2<i>p</i>-electron excitation in Mg-Mg, Al-Al, and Si-Si symmetric collisions

Abstract

Target LMM atomic Auger electron emission has been studied by low-energy ion bombardment on light-element surfaces. Our results show that the threshold energies for Mg, Al, and Si 2p core electron excitation are the same for impact of ${\mathrm{Ar}}^{+}$, ${\mathrm{Kr}}^{+}$, and ${\mathrm{Xe}}^{+}$ projectiles but are substantially lower for ${\mathrm{Ne}}^{+}$. A sensitive dependence of the energy onset on the ion incidence angle has also been observed. The intensity behavior in the near-threshold energy range is in excellent agreement with simple kinematic calculations using a binary-collision model and by taking into account only the first target-target symmetric encounters.