The projectile electron loss channel plays an important role in modeling several processes connected to the penetration of swift ions in gases, such as radiation damage, energy loss, upper atmosphere studies, storage lifetimes of low-charge state heavy ions, etc. In this paper we have used recent measurements of projectile electron loss of He+ ions in N2 together with previous data for higher charged ions in order to shed light on the role played by the projectile electron loss in the heating and ionization of Titan's atmosphere.

The Independent Event Model (IEVM) is used to analyze collision processes for systems with three and four electrons, in situations where up to three active electrons are involved and dynamical correlation effects play a major role. The model is applied to single electron loss and loss-ionization processes. All the possible ionization mechanisms for both collision partners in each exit channel are considered, including antiscreening, which, in the IEVM, can be taken into account in a consistent way along all the other ones, keeping unitarity. As a casestudy, the IEVM is applied to the analysis of the single loss of He+, Li+, and Li2+ ions by He atoms with the simultaneous single and double ionization of the target. We present plots of the cross sections of single electron loss accompanied or not by the ionization of the target as functions of the projectile energy. The calculations describe well the experimental energy dependence and the high-velocity absolute values for the cross sections.