Auger neutralization rate for slowAr+ions in front of KCl(001)

Abstract

Angular and charge-state distributions are measured for $5--15\text{\penalty1000-\hskip0pt}\mathrm{keV}$. ${\mathrm{Ar}}^{0}$ and ${\mathrm{Ar}}^{+}$ ions reflected from a KCl(001) surface under glazing angle incidence. The ionization of ${\mathrm{Ar}}^{0}$ is almost completely suppressed at incident angles smaller than a critical angle ($11--22\phantom{\rule{0.3em}{0ex}}\mathrm{mrad}$, depending on the ion energy), while a considerable fraction of incident ${\mathrm{Ar}}^{+}$ ions are neutralized. It is demonstrated that a position-dependent Auger neutralization rate can be derived from the observed result without any assumption except for the surface continuum potential. The obtained Auger neutralization rate shows a simple exponential dependence as is usually assumed.