Charge-exchange processes involving C60 fullerenes and their ions

We report the results of calculations of charge-exchange processes in collisions involving fullerenes and their ions. For charge-exchange processes in collisions between fullerenes and multiply charged ions, we develop a semiclassical approach based on the decay model combined with the impact-parameter representation for the heavy-particle relative motion. In this model, the charge-transfer process is considered as a transition of the active electron over and under the quasistatic potential barrier formed by the electric fields of the target and projectile. In all our calculations, we represent a fullerene as a perfectly conducting hard sphere, and the energies of the active electrons are assumed to be equal to the corresponding ionization potentials, including the Stark-shift effect. Using the phase-shift approach we evaluate the electron transmission coefficient through the asymmetric potential barrier. It is shown that our theory is in fairly good agreement with the available experimental data on single-electron charge-exchange processes. The advantage of the approach developed consists in the fact that it allows us to provide an accurate description of multielectron-transfer processes. Special attention in our work is also paid to the consideration of charge-exchange processes in fullerene-fullerene collisions. Here we show that the cross sections of charge-transfer processes in collision systems of C-60 (+) + C-60 (2+) and C-60 + C-60 (+) turn out to be close to each other.