Perda e captura eletrônica de Li2+ colidindo com Ar, na faixa de energia entre 0,5 e 3,0 MeV

Abstract

Total cross sections of loss and electron capture of Li2+ in Ar were measured in the range of energy from 0,5 to 3,0 MeV. The experimental data for loss are compared with theoretical calculations based in the Plane Wave Born Approximation (PWBA) and on the Model of Free Collisions. The electronic loss may happen basically from two different modes, the so-called screening and antiscreening. In the screening mode the loss is due to the interaction of the screened target nucleus with the electron active of projectile and in the antiscreening mode the loss is due the interaction of the electron active of target with the electron active of projectile. The measures of the total cross sections of loss in this work present values well bellow of the theoretical calculations, this can due to a coupling of the loss and electronic capture channels on a same collision that are not taken into account in such a way in the PWBA how much in the MCL; and in the case of the PWBA the difference experiment-theory is bigger, therefore this approach is perturbative. For the treatment with heavy targets, the nonperturbative theories show a description more satisfactory, but it must be considered the coupling of competitive channels of loss and electronic capture on the same collision for a correct description of the problem. These measures are unpublished on the literature, and come in order to contribute for the treatment of collisions that involves multicharged ions and heavy targets.