Electron emission from a metal surface bombarded by slow highly charged ions

Abstract

We have measured total electron-emission yields \ensuremath{\gamma} for clean tungsten bombarded with various multiply charged ions: ${Z}^{q+}$ up to ${\mathrm{N}}^{6+}$, ${\mathrm{Ne}}^{7+}$, ${\mathrm{Ar}}^{12+}$, and ${\mathrm{Kr}}^{11+}$. At low impact energy (\ensuremath{\le}10 eV/amu) a linear dependence of \ensuremath{\gamma} versus ion potential energy could be observed up to the respectively highest q, for which a pronounced decrease appeared superimposed on the gradual decrease of all \ensuremath{\gamma} toward higher impact energy. Our results are discussed within a multiple-step ion-neutralization model.