Multielectron Processes in Heavy Ion–Atom Collisions at Intermediate Velocity

Abstract

International audienceUsing high resolution x-ray spectroscopy, we have measured projectile electron single and multiple cross sections when a two-electron Ar16+ ion collides with neutral target atoms. For a fixed impact velocity (vp = 23 a.u.), but using various targets from He to Xe, a range from the perturbative regime to the strong interaction regime has been investigated. Double excitation cross sections are found to be well reproduced by an independent electron model. First measurements of capture-ionization cross sections are also reported and show the importance of this often-neglected process

Fast ion-induced CO molecule fragmentation in the strong interaction regime

“…We present here the coincident time of flight technique and the procedure used to determine these kinetic energy release (KER) distributions, the branching ratios between the different dissociation pathways (C q1+ /O q2+ ) and the multi-electron removal cross sections. All of these results will be discussed in the light of recent theoretical (Rodriguez andSalin 1992, Martín andSalin 1995) and experimental (Vernhet et al 1997, Adoui et al 1999 advances in ion-atom collision works as well as with the scarce fast ion-molecule results. Finally, one channel of dissociative single ionization, involving a neutral fragment, was studied by recoil ion momentum spectroscopy (RIMS).…”

Extension of charge-state-distribution calculations for ion-solid collisions towards low velocities and many-electron ions

“…colliding with neutral targets of increasing atomic number. Here PWBA starts overestimating cross sections for K p values above 0.4, whereas the SEIK model reproduces well the experiment up to K p values larger than 2 [21,22].…”

Charge dependence of electron emission in swift heavy-ion collisions with carbon

“…20 It was shown that such a so-called ''saturation effect'' ͑sometimes also called the ''nonlinear effect''͒ is not predicted by the first Born approximation, which would end up as a Q P 2 law and is only valid for small perturbations. It is then conceivable that this ''saturation effect'' observed in ion-atom collisions also takes place in a solid target, where, however, the electronic structure of the target and consequently the interaction cross sections are different.…”