Part of the High-Energy-Density-Matter group activity is devoted to the theoretical study of plasma sources for nanolithography and to the rather complex physical phenomena involved in such sources. One will find first an overview of the motivations of this work.

A first formalism used is based on the superconfiguration theory.

In order to improve the atomic description, noticeably to describe the non-independent character of the ionic electrons which appears as configuration interaction we are using a parametric potential code. The improvements of the current formalism are oriented towards a description out of local thermodynamic equilibrium, based here on a semi-empirical computation of the ionic distribution. Moreover, it is foreseen to use collisional-radiative codes to compute more accurately the level populations.