Molecular structure effects in the energy loss of swift boron molecular ions in solids

Abstract

We analyse the effects on the stopping power due to the geometrical structure of swift Bn+ (n = 2-6) ions incident on amorphous carbon targets. We use the dielectric formalism to describe both the interaction of the projectile with the stopping medium and the vicinage effects on the atomic ions resulting from the dissociation of each Bn+ ion. The variation of the energy loss with the temporal evolution of the relative positions of the atomic ions, due to Coulomb explosion, has also been taken into account. The calculated stopping power ratio for each Bn+ ion reproduces fairly well the main trends, as a function of the dwell time, observed in the available experimental data. The differences among the stopping power ratios of the Bn+ ions disappear as the number of atomic ions, n, increases.