| The strengths and realms of applicability of the two most common techniques for simulating the penetration of matter by fast ions, the Binary Collision and Molecular Dynamics methods, are discussed in an introduction. Later chapters are based on research topics completed by the author during his graduate career. In the first research chapter, simulations including the effects of K-shell Li vacancy production during backscattering from an Al target are performed and compared to experimentally obtained results. The dependence of the probability of vacancy production upon distance of closest approach between Li and Al atoms is determined. The standard interpretation of the model of Barat and Lichten (Phys. Rev. A 6 (1971) 211) is found to be inadequate; rather than a step function dependence, a gradual turning-on of the vacancy production probability with decreasing distance of closest approach is found. A partial explanation for the failure is the 'solid effect' mentioned by those authors. In the second research chapter, the results of simulations of cluster formation during Ar{dollar}sp+ to{dollar} In-Ga (liquid) sputtering events are presented and an event-size-specific recombination model describing the formation of clusters during sputtering is developed. A strong correlation between the size of the sputtering event and the size of clusters it produces is found in the simulations and predicted by the model. In the final research chapter, a new algorithm capable of efficiently simulating the penetration of matter by fast clusters is developed and used to predict intra-cluster correlations as the cluster penetrates successively thicker targets. These correlations are then compared to experimentally observed yields of H{dollar}sp+{dollar} desorbed from the exit sides of targets of similar thicknesses; the length scale of the desorption process is thus determined. |
