The target-density effect in electron-capture processes

Abstract

The influence of the target density on the electron-capture (EC) processes in collisions offast ions with atoms and molecules is considered. The partial EC cross sectionsσn on the principalquantum number n of the scattered projectile, as well as the totalσtot = Σnσn values,are calculated for highly charged ions interacting with gaseous and solid targets in the energy rangeof E = 100 keV u−1 to 10 MeV u−1. It is shown that with the target density increasing, the populations of the excited states ofthe scattered projectiles, formed via the EC channel, are drastically suppressed due toprojectile ionization by the target particles and, as a result, the total EC cross sectionsdecrease by orders of magnitude at low energies, while the reduction is less prominent athigh energies.