A CHARGE STATE APPROACH TO THE STOPPING POWER OF IONS IN SOLIDS

A continuous capture and loss picture is used to calculate the stopping power of ions in solids at intermediate velocities. The total stopping power is obtained by weighting the appropriately calculated stopping powers of each charge state with the respective charge state fraction and adding the energy loss per unit path length due to electronic exchange processes. Linear response theory in the dielectric formalism and atomistic models are combined with many-body techniques to obtain the charge state distribution of ions with inclusion of solid state effects. The different mechanisms responsible for the charge exchange processes and the way of calculating the stopping for each charge state are also discussed. Results are presented for the particular case of He projectiles in solid Al targets, showing good agreement with the available experimental data.