Multiple electron processes from H2O by He2+ and Li3+ impact

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

Cairns

Conferencia; The XXX International Conference on Photonic, Electronic, and Atomic Collisions; 2017

Investigation of single and multiple-electron removalprocesses occurring between fully stripped ions and H2O molecules isof fundamental interest in many areas such as nuclear fusion [1], plasmaphysics [2] and others. In particular, it is of fundamental importance in radiotherapy[3] enabling the understanding of the basic governing mechanisms involved. A largevariety of final projectile and target charge states may be produced during theseprocesses. Consequently, calculations of cross sections of pure ionization,capture and transfer-ionization reactions are essential to determine the mainfeatures of multiple electron processes. He2+ and Li3+ beamsare chosen in this work. The three-body Continuum Distorted Wave-EikonalInitial State approximation (3B-CDW-EIS) [4] is used to calculate transitionprobabilities (capture and ionization) as a function of the impact parameterand absolute cross sections for the considered collisions. The initialwavefunctions of the active electrons bound to a particular water molecularorbital are described employing the complete neglect of the differentialoverlap (CNDO) approximation [5]. A trinomial distribution analysis has beenemployed to compute exclusive probabilities using the independent electron(IEL) model, where electron correlation is neglected [6]. A unitarizationprocedure is employed to avoid overestimations of 3B-CDW-EIS impact parameterprobabilities. From the comparison with the available theoretical and recentexperimental results, we conclude that inclusive probabilities are required fora reliable description of the processes of interest for single-electron removalprocesses (see Figure 1) and exclusive probability analysis formultiple-electron ones. The developed method for calculation of one-electronionization and capture probabilities allows to study multiple electronprocesses for complex targets in particular such as macromolecules of DNA andRNA to model scenarios for the radiobiological consequences of the impact ofcharged energetic particles on those macromolecules.