Etude des processus d'ionisations (e,2e), (e, 3e) et ([gamma], 2e) des systèmes atomiques à deux électrons

Abstract : The presented work concerns the theoretical studies of (e, 2e), (e, 3e) and ([gamma], 2e) ionization process relative to two-electron targets, notably on : - the description of two-electron atomic or ionic systems, with the construction of a set of states describing the target in its ground state, and taking into account electronic correlations in the target ; - the description of the double continuum associate to the both emergence electrons with the positive energies in a coulomb field, in prolonging the method of Brauner et al. (1989). For (e, 2e) single ionization of helium, we have tempted to cover a large range of the possible kinematics, by showing in each of these regimes the importance of pre- and post-collision interactions, especially near the threshold. At low energy, and taking into account the indiscernability of electrons, we study exchange and capture effects. We have shown for the first time the importance of the capture contribution in the ionization cross sections. Furthermore, the study of dynamic screening effects (Berakdar 1996) has been also investigated. Confrontations of our results to various anterior calculations as well as to experimental data have allowed us, in most cases, to confirm the interest and the validity of our approach. We have also presented the cross sections of double ionization (e, 3e), and showing the correlation effects in the target and these resulting from the post-interactions. Furthermore, the cross sections of type (e,3-1e) have been calculated. Finally, this method has been applied to the study of the process of photo-double ionization ([gamma], 2e). It is worth noting that our results are in good agreement with recent experimental measure
Complete list of metadatas

Cited literature [65 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01777232
Contributor : Administrateur Du Ccsd <>
Submitted on : Tuesday, April 24, 2018 - 4:15:04 PM
Last modification on : Thursday, April 26, 2018 - 1:28:31 AM
Long-term archiving on : Thursday, September 20, 2018 - 12:00:58 AM

File

Najjari.Bennaceur.SMZ9753.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01777232, version 1

Collections

Citation

Bennaceur Najjari. Etude des processus d'ionisations (e,2e), (e, 3e) et ([gamma], 2e) des systèmes atomiques à deux électrons. Autre [cond-mat.other]. Université Paul Verlaine - Metz, 1997. Français. ⟨NNT : 1997METZ053S⟩. ⟨tel-01777232⟩

Share

Metrics

Record views

27

Files downloads

23