Eur. Phys. J. D 44, 525-532 (2007)
https://doi.org/10.1140/epjd/e2007-00216-4

Fragmentation induced by charge exchange in collisions of charged alkaline clusters with alkali atoms

¹ Institut de Minéralogie et Physique des Milieux Condensés, Université Pierre et Marie Curie, Campus Boucicaut, 140 rue de Lourmel, 75015 Paris, France
² Departamento de Química, C-9, Universidad Autónoma de Madrid, 28049 Madrid, Spain
³ Laboratoire de Physique Moléculaire et des Collisions, Institut J. Barriol (FR-CNRS 2843), Université de Metz, Technopôle 2000, 1 boulevard Arago, 57078 Metz Cedex 03, France
⁴ Université Paul Sabatier, Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, 118 route de Narbonne, 31062 Toulouse, France
⁵ Institut de Physique et Chimie des Matériaux de Strasbourg, GONLO, 23 rue Loess, 67034 Strasbourg, France

Corresponding author: ^a mpolitis@ccr.jussieu.fr

Received: 16 March 2007
Published online: 27 June 2007

Abstract

We present a theoretical study of the dissociative charge transfer processes induced by collisions between doubly-charged alkaline clusters and alkaline atoms at slow and intermediate impact energies. Charge-exchange cross sections have been evaluated for the collisions of Li₃₁²⁺ and Na₃₁²⁺ clusters with neutral alkaline atoms (Cs and Na) at impact energies between 500 and 4000 eV. The branching ratios of the evaporation processes have been calculated within the framework of the microcanonical statistical theory of Weisskopf. The key ingredient of this model is the cluster vibrational density of states. An approach based on quantum tight-binding Hamiltonian is introduced, allowing us to evaluate this quantity at a microscopic level, including quantum vibrational effects at low temperatures. Comparison with previously reported results obtained using a macroscopic description of the level density are presented and discussed.