Skip to Main content Skip to Navigation
Theses

Etude de l'influence de l'environnement plasma sur les sections efficaces d'excitation collisionnelle électron-ion dans un plasma chaud et dense

Abstract : Collisional excitation cross-sections are essential for the modeling of the properties of non equilibrium plasmas. There has been a lot of work on electron impact excitation of isolated ions, but in dense plasmas, neighboring particles are expected to widely disturb these electron transitions in atoms. Plasma modeling through a radially perturbated potential has already been done but is not satisfactory as it does not account for levels degeneracy breaking and its consequences. Introduction of a quasistatic electric microfield of neighboring ions allows us to break spherical symmetry. Our original theoretical study has given birth to a numerical code that accurately computes collisional strengths and rates (in the Distorted Waves approach) in atoms submited to a realistic microfield. Hydrogen- and helium-like aluminium is studied. Stark mixing widely increases rates of transitions from high l levels and forbidden transitions are field-enhanced by many orders of magnitude until they reach allowed ones. Eventually, we conduct an elementary stationary collisional radiative study to investigate field-enhancement effects on corresponding line shapes. In cases we study (aluminium, hydrogen- and helium-like) we find a relatively weak increase of K-shell line broadening.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00008508
Contributor : François de Gaufridy de Dortan <>
Submitted on : Wednesday, February 16, 2005 - 12:36:34 PM
Last modification on : Monday, October 19, 2020 - 11:05:58 AM
Long-term archiving on: : Friday, April 2, 2010 - 9:34:34 PM

Identifiers

  • HAL Id : tel-00008508, version 1

Collections

CEA | DAM

Citation

François de Gaufridy de Dortan. Etude de l'influence de l'environnement plasma sur les sections efficaces d'excitation collisionnelle électron-ion dans un plasma chaud et dense. Physique Atomique [physics.atom-ph]. Université Paris Sud - Paris XI, 2003. Français. ⟨tel-00008508⟩

Share

Metrics

Record views

250

Files downloads

397