Ion-induced desorption in insulators by Hydrogen cluster impact up to 600 KeV

Abstract

Time-of-flight spectrometry has been used for measurements of Cs⁺ ions emitted from cesium iodide targets by 600 keV hydrogen cluster ions H _n ⁺, with n ranging from 5, 7, 9, … to 23. Evidence for an enhanced yield with respect to the sum of the individual atoms in a cluster is reported. The increase of the yield as a function of the projectile mass exhibits a fourth power dependence on the additive stopping power (n times the electronic stopping power of the proton at the same velocity). Similar trends are found from preliminary results on the variation of the yield as a function of the cluster energy. Such non-linearity is discussed on the basis of existing models for monoatomic ions. Since the experimentally observed yields can reach ∼10% for mass 21 it is suggested that an interesting analytical application should be a simple microprobe system.