Cooking strongly coupled plasmas

Abstract

We present the orbital-free method for dense plasmas which allows for efficient variable ionisation molecular dynamics. This approach is a literal application of density functional theory where the use of orbitals is bypassed by a semi-classical estimation of the electron kinetic energy through the Thomas-Fermi theory. Thanks to a coherent definition of ionisation, we evidence a particular regime in which the static structure no longer depends on the temperature: the -plateau. With the help of the well-known Thomas-Fermi scaling laws, we derive the conditions required to obtain a plasma at a given value of the coupling parameter and deduce useful fits. Static and dynamical properties are predicted as well as a a simple equation of state valid on the -plateau. We show that the one component plasma model can be helpful to describe the correlations in real systems.

Parametrization of pair correlation function and static structure factor of the one component plasma across coupling regimes

“…15,16 Interestingly, when the plasma is partially ionized, the coupling parameter Γ can stay constant along isochores as a result of the increase of ionization compensating the increase of temperature. [17][18][19][20] In plasma mixtures, the coupling parameter Γ may be different for each species giving rise to interesting coexistences between different coupling regimes. [21][22][23] In the Yukawa model, the polarization of the electrons close to each ion is accounted for by a screened potential V Y (r) = Qe exp(−κr)/r, where κ is an inverse screening length.…”