Screening models for laser–cluster interactions

We study the applicability of various screening approaches within the context of laser–cluster interactions. Comparisons between well-known screening models, such as the static screened Coulomb, Debye–Hückel, Thomas–Fermi and ion–sphere ones, and a more elaborated approach based on the Lindhard dielectric function within the linear response theory (Gupta and Rajagopal 1982 Phys. Rep. 87 261) show that none of the simpler classical models can be used through the complete range of plasma situations encountered in laser–cluster interactions. Therefore, we have clearly specified the validity domains of the various models as well as the regions of electronic temperature and density where Friedel oscillations appear.