Investigations of electron removal processes in slow He²⁺- and He⁺-Ne₂ collisions and of their implications for the subsequent dimer fragmentation through interatomic Coulombic decay

Abstract We implement an independent-atom and independent-electron model to investigate the collision systems of He 2+ and He + ion projectiles impinging on a neon dimer target. The dimer is set to be stationary at its equilibrium bond length with the projectile traveling parallel to the dimer axis at a speed corresponding to the collision energy of 10 keV amu −1 . Two approaches, namely multinomial and determinantal, are used as an analysis of these collisions. Each of the analyses is broken down into two types of models that do not and do include a change in the projectile charge state due to electron capture from the dimer. All calculations are performed using both a frozen atomic target and a dynamic response model using the coupled-channel two-center basis generator method for orbital propagation. All one-electron and two-electron removal processes are calculated, though particular attention is paid to those that result in the Ne + -Ne + fragmentation channel due to its association with interatomic Coulombic decay (ICD). For He 2+ impact, we find that Ne(2 s ) electron removal is strong across all analyses and models, which is in line with previous results that show that ICD contributes to dimer fragmentation through that channel. We also find indications that there is a pure ICD yield when utilizing a He + projectile and applying the model that takes into account the change in projectile charge state.