Multiple Electron Processes in Helium impacted by H + , He 2+ and Li 3+ Ions

M. A. QUINTO; R. D. RIVAROLA; P.R. MONTENEGRO; O.A. FOJÓN; P.N. TEREKHIN; JUAN M. MONTI

Frankfurt

Conferencia; 12th European Conference on Atoms Molecules and Photons; 2016

Collisions of bare ion projectiles impacting on He atoms are the simplest systems for investigation ofsingle and multiple electron transitions. The study of these collisional systems is crucial to fully understand themechanisms underlying these basic reactions. Moreover, they are of interest in several fields such as heavy-iontherapy [1], thermonuclear fusion [2], hot plasmas [3], etc.In this work, multiple electron processes (single and multiple ionization, single capture, transfer-ionization) of He targets impacted by H + , He 2+ and Li 3+ projectiles are analyzed theoretically in detail atintermediate and high collision energies. Absolute cross sections for these processes are obtained by computationof transition probabilities as a function of the impact parameter in the framework of the Continuum DistortedWave-Eikonal Initial State theory (CDW-EIS) [4]. A binomial analysis is employed to calculate exclusiveprobabilities using the independent electron (IEL) model, where static and dynamic correlations are neglected[5], as well as the independent event (IEV) model, in which the ionization is viewed as a two step process [6]. Itis worthy to note that only exclusive probabilities are able to describe properly the measured cross sectionstaking into account all possible processes. Total single electron ionization cross sections as a function of theincident projectile energy for H + impacting on He targets are displayed in figure 1.