Primary processes: from atoms to diatomic molecules and clusters

X Fléchard ,D Hennecart ,Martino Trassinelli ,Jean-Yves Chesnel ,A Méry ,L Adoui ,P Jardin ,O Naviliat‐Cuncic ,D Lelièvre ,E Liénard ,A Cassimi ,G Ban ,J P Grandin ,J.m Ramillon ,J.p Rozet ,L Maunoury ,S Steydli ,E Jacquet ,F Frémont ,P Boduch ,Christophe Prigent ,Jimmy Rangama ,Dominique Durand ,S Guillous ,Emily Lamour ,Dominique Vernhet

doi:10.1088/1742-6596/629/1/012001

Abstract

This article presents a short review of the main progresses achieved at the GANIL facilities during the last thirty years in the field of ion-atom and ion-diatomic molecule collisions. Thanks to the wide range of projectile energies and species available on the different beam lines of the facility, elementary processes such as electron capture, ionization and excitation have been extensively studied. Beside primary collision mechanisms, the relaxation processes of the collision partners after the collision have been another specific source of interest. Progresses on other fundamental processes such as Young type interferences induced by ion-molecule collisions or shake off ionization resulting from nuclear beta decay are also presented.

Highlights

For the electronic structures of atoms and molecules, precise theoretical knowledge and highresolution experimental data are available
Combined with complementary experiments using He+ and He2+ projectiles in the 0.1-0.2 MeV/u energy range on neon and argon dimer targets, the results suggest that inter atomic Coulombic decay (ICD) is omnipresent and a major contributor of low-energy electron emission in fast ion collisions with loosely bound targets [154]
The kinetic energy release (KER) spectrum of the Ar+ + Ar+ fragmentation channel allowed to identify one-site double capture process populating bound transient states that can only decay through radiative charge transfer (RCT)

Summary

Introduction

For the electronic structures of atoms and molecules, precise theoretical knowledge and highresolution experimental data are available. The collision strength parameter K = (ve/vp) (Zt/Zp) defines the collision regime such as the strong interaction regime (K>>1) where electron capture is by far the most probable process, the perturbative regime (K

Achievements in ion-atom collisions

Collisions with diatomic covalent molecules

Probing other fundamental processes

Findings

Conclusions and perspectives