Ionization of water molecules by fast dressed H, He + and He ion beam impact

C. CHAMPION; M. A. QUINTO; J.M. MONTI; R. D. RIVAROLA

Foz de Iguazu

Conferencia; 9th International Symposium on BioPIXE (BioPIXE 2018); 2018

Ionization of water molecules by multi-charged fast ions has been vastly studied over the lastyears in both theoretical and experimental aspects (e.g. [1-3]). This is not the same for the caseof water molecules ionization by dressed or neutral projectiles impact where only a fewexperimental results are found in the bibliography, mainly for total cross sections [4-7]. Even lessare the experiments that were performed in a way that electron emission from the water moleculetarget as well as from the ionic or atomic projectile can be distinguished. It is important to highlightthat the study of electron emission from molecular targets by bare, partially-dressed, or neutralprojectiles is of main interest not only in atomic and molecular physics but also in other areassuch as plasma physics and radiobiology.With the intention of encouraging the scientific community to perform experiments where thetarget and projectile ionization can be distinguished, we present theoretical results regarding theionization of vapour water molecules by impact of neutral H and He atoms and He + ion. A set oftotal, simply, and doubly differential cross sections are calculated within the Continuum DistortedWave-Eikonal Initial State (CDW-EIS) model. For neutral projectile, this theoretical description isreduced to a first-order Born approximation.Comparison with the scarce existing experimental results will be presented (see Figure). Detailson the theoretical model and calculations will be given during the conference.