Ion Group And The Mechanism Of The Interaction Of Solid Materials

Interactions between ion clusters and solids have been researched theoretically in the present work. The dielectric response formalism is used to evaluate the dynamically screened interaction potential among the ions in a fast cluster passing through a solid target. This potential is further used to calculate the individual ion charge states in the cluster by means of a statistical-variational theory which takes into account the effects of the vicinity of the neighbouring ions. Coulomb explosions and the energy losses of the cluster are simulated by solving equations of motion for individual ions while taking into account, in a self-consistent manner, the variation of ion charges in the course of explosions. Moreover, a Monte-Carlo method is used to simulate the effects of the multiple scattering of the cluster constituent ions on target atoms. Whether the ions collide with atoms in solid target or not is judged in each time interval. If a collision is taken place, the velocity of the ion will change.In this paper, diatomic molecular ions are studied firstly. Then it is extended to the case of lager clusters, such as C20 and C60.It is found that, owing to the wake-like asymmetry of the inter-ionic potential, both the distribution of ion charges in the cluster and the Coulomb explosion patterns exhibit strong spatial asymmetries in the direction of motion. It is also shown that the cluster energy losses exhibit characteristic interferences due to the vicinity effects, which diminish after long dwell times. The multiple scattering effects hinder the Coulomb explosion of the clusters.