Theoretical description of two- and three-particle interactions in single ionization of helium by ion impact

M. CIAPPINA; WALTER R. CRAVERO; M. SCHULZ; R. MOSHAMMER; J. ULLRICH

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

American Physical Society

Lugar: Ridge, New Yor, USA; Año: 2006 vol. 74 p. 427021 - 427029

1050-2947

In this work we calculate doubly differential cross sections (DDCS) for single ionization of helium by highly charged ion impact. We study the importance of two-particle interactions in these processes by considering the cross sections as a function of all two-particle subsystems momenta. Experimental DDCSs were obtained recently from kinematically complete experiments on single ionization of He by 100  MeV/amu C6+ and 3.6  MeV/amu Au24,53+ impact. Furthermore, we evaluated the importance of three-particle interactions by plotting the squared momenta of all three collision fragments simultaneously in a Dalitz plot. Using the first Born and distorted-wave approximations for fully differential cross sections, together with Monte Carlo integration techniques, we were able to reproduce the main features observed in experimental data and to assess the quality of the models implied by the different employed approximations.