title: Extent of validity of the hydrodynamic description of ions in dense plasmas.
abstract: We show that the hydrodynamic description can be applied to modeling the ionic response in dense plasmas for a wide range of length scales that are experimentally accessible. Using numerical simulations for the Yukawa model, we find that the maximum wave number k(max) at which the hydrodynamic description applies is independent of the coupling strength, given by k(max)λ(s)≃0.43, where λ(s) is the ionic screening length. Our results show that the hydrodynamic description can be used for interpreting x-ray scattering data from fourth generation light sources and high power lasers. In addition, our investigation sheds new light on how the domain of validity of the hydrodynamic description depends on both the microscopic properties and the thermodynamic state of fluids in general.
authors.affiliation: Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom. james.mithen@physics.ox.ac.uk
authors.forename: James P
authors.initials: JP
authors.lastname: Mithen
authors.forename: Jérôme
authors.initials: J
authors.lastname: Daligault
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gregori