Proton impact fragmentation of water molecules

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

Cairns

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

Interaction of charged particles with moleculartargets is of great interest in a number of areas of research such as nuclearfusion [1], plasma physics [2] and others. Particularly, collisions of ions withH2O are of great importance in radiotherapy [3]. The ionization ofwater molecules produce different charged species, which can damage the surroundingcells. Therefore, it is important to analyze pure ionization, capture andtransfer-ionization reactions to study fragmentation processes. We presenttheoretical calculations of fragmentation cross sections based on the modelproposed in the work [4] for water molecules interacting with H+impact. In the present work, cross sections are obtained in the framework of thethree-body Continuum Distorted Wave-Eikonal Initial State approximation(3B-CDW-EIS) [5]. The initial wavefunctions of the active electrons bound to aparticular water molecular orbital are described employing the complete neglectof the differential overlap (CNDO) approximation [6]. A trinomial distributionanalysis has been employed to compute exclusive probabilities using the independentelectron (IEL) model. A unitarization procedure is employed to avoidoverestimations of 3B-CDW-EIS impact parameter probabilities. From thecomparison with the available theoretical and recent experimental results, weconclude that exclusive probabilities are required for a reliable descriptionof the fragmentation yields (see Figure 1). The developed approach may be usedto investigate fragmentation patterns of more complex molecules.