Abstract
Sputtering and ion emission rates have been measured from CsI and gold targets under the impact of
Au
n
+
(
n
=
1–9) clusters at energies between 30 and 350
keV/atom. The two materials have similar behaviors in regard to the variations of the sputtering and anion emission yields with energy and cluster size. The sputtering and anion emission yields increase nonlinearly with the projectile size. The maximum anion yields are found at lower energies than the maximum sputtering yields which themselves occur substantially below the maximum energy losses. The variations with energy of the atomic ion yields differ from those of the cluster ion yields. The experimental results are in agreement with an ion emission from linear collision cascades and spike collisions, the relative contribution of these two processes depending on the size of the cluster projectile and of the emitted ion. In addition they show that the ion emission yield enhancements under cluster impact result from a more effective sputtering mechanism and not from an enhanced ionization of the ejected species.