SINGLE AND DOUBLE ELECTRON PROCESSES OF HELIUM TARGETS INDUCED BY FULLY STRIPPED ION IMPACT

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

Kielce

Conferencia; HCI 2016 is the 18th in a series of International Conferences on the Physics of Highly Charged Ions.; 2016

Collisions between fully stripped ions and He targets are the simplest systems forinvestigation of multiple electron transitions. The study of these collisional systems is crucialto fully understand the mechanisms underlying these basic reactions. Moreover, they are ofinterest in several fields such as heavy-ion therapy [1], thermonuclear fusion [2], hot plasmas[3], etc.In this work, multiple electron processes (single and double ionization or capture, as well astransfer-ionization) of He targets impacted by H + , He 2+ and Li 3+ projectiles are analyzedtheoretically in detail at intermediate and high collision energies. Absolute cross sections forthese processes are obtained by computation of transition probabilities as a function of theimpact parameter in the framework of the Continuum Distorted Wave-Eikonal Initial Statetheory (CDW-EIS) [4]. A binomial analysis is employed to calculate exclusive probabilitiesusing the independent electron (IEL) model, where electron correlation is neglected [5], aswell as the independent event (IEV) model, in which the ionization is viewed as a two-stepprocess [6]. It is worthy to note that only exclusive probabilities are able to describe properlythe measured cross sections taking into account all possible processes.The comparison with the available theoretical and experimental results shows that exclusiveprobabilities are needed for a reliable description of the experimental data. The total crosssections obtained within the IEV model and using exclusive probabilities are in betteragreement with the experimental results than previous IEV calculations. The developedapproach may be used to obtain the input database for modeling multiple electron processesof energetic charged particles passing through matter.References[1] U. Amaldi and G. Kraft, Rep. Prog. Phys. 68, 1861 (2005)[2] Simon S. Yu, B.G. Logan, J.J. Barnard et al., Nucl. Fusion 47, 721 (2007)[3] I. Murakami, J. Yan, H. Sato et al., At. Data Nucl. Data Tables 94, 161 (2008)[4] P.D. Fainstein, V.H. Ponce and R.D. Rivarola, Phys. B: At. Mol. Opt. Phys. 24, 3091(1991)[5] J. Bradley, R. J. S Lee, M. McCartney and D. S. F. Crothers, J. Phys. B: At. Mol. Opt.Phys. 37, 3723 (2004)[6] D. S. F. Crothers and R. McCarroll, J. Phys. B: At. Mol. Phys. 20, 2835 (1987)