Experimental and theoretical results on electron emission in collisions between partially-dressed

MONTI, J. M.; FREGENAL, D.; SUÁREZ, S.; HORSDAL, E.; WOLFF, W.; FAINSTEIN, P. D.; RIVAROLA, R. D.; BERNARDI, G.; FIOL, J.

Heidelberg

Congreso; 16th International Conference on the Physics of Highly Charged Ions; 2012

The study of electronic reactions in collisions between partially-dressed projectiles with atomic targets has received increasing interest over the last two decades. These systems have provided suitable framework to investigate the relative importance of the electron-electron interaction in comparison to the interaction of the emitted electron with the screened nucleus. In this work we present experimental and theoretical results on the electron emission between swift partially-dressed Liq+ and Alq+ ions (q = 1, 2, 3) impinging on He atoms. The interesting feature of these systems relies on the fact that in both cases the projectile electrons are not bound enough to be considered passive electrons (frozen in their orbitals during all the reaction)and thus target, projectile and even simultaneous ionization can occur.Experimental doubly differential cross sections for electron emision induced by intermediate energy projectiles are compared with classical CTMC and quantum CDW and CDW-EIS theoretical models. In the case of CTMC, electrons from both centers are considered. The interactions of the electrons with both nuclei as well as the interaction between electrons fromdifferent centers are shown to produce ionization. The quantum CDW and CDW-EIS models, originally developed to the case of bare projectiles, where recently extended by Monti et al. [1,2] to the case of partially-dressed ones. In this extension the target active electron-projectile interaction is approximated in terms of a GSZ two-parameter potential [3]. Results of doubly differential cross sections as a function of electron energy for a wide variety of angles and several impact energies will be presented at the conference along with theoretical details. The comparison between the three theories, and with the experimental data, allow us to discuss the role played by short- and long-range interactions, as well as the relative importanceof target, projectile and simultaneous ionization in the observed spectra.References[1] Monti J M, Rivarola R D and Fainstein P D 2008 J. Phys. B: At. Mol. Opt. Phys. 41 201001[2] Monti J M, Rivarola R D and Fainstein P D 2011 J. Phys. B: At. Mol. Opt. Phys. 44 195206[3] Green A E S, Sellin D L and Zachor A S 1969 Phys. Rev. 184 1