Electrical conductivity of a partially ionized plasma with allowance for the effect of plasma screening on the electron
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DEAL PLASMA
Electrical Conductivity of a Partially Ionized Plasma with Allowance for the Effect of Plasma Screening on the Electron Scattering by Neutral Atoms V. S. Karakhtanov Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow oblast, 142432 Russia Received April 11, 2006
Abstract—Using linear response theory, the effect of electron–atom scattering on the electrical conductivity of a partially ionized hydrogen plasma is studied in the relevant statistical operator approximation. A relationship is analyzed between the polarization potential, which is routinely used in the problem, and the adiabatic potential, which results from the separation of electrons into bound and unbound ones. An approximation accounting for the effect of unbound electrons on the interaction between neutral and charged plasma particles is constructed. It is found that, in a high-density plasma, the parameters of the interaction of an atom with charged particles can change significantly, so these changes should be taken into account in calculating kinetic plasma properties. PACS numbers: 52.25.Fi, 52.27.Gr DOI: 10.1134/S1063780X07030087
1. INTRODUCTION Investigation of plasmas under strong heating and compression conditions is very interesting both from a general physical standpoint and from a practical standpoint for astrophysics, the physics of giant planets, and promising energy applications [1]. Experiments on shock and multiple compression of hydrogen and noble gases made it possible to derive empirical information on a new (previously uninvestigated) portion of the phase diagram [2]. The densities achieved in compression are one order of magnitude higher than those of solid hydrogen and noble gases, in which the mean distance between the protons is comparable to the characteristic sizes of molecules and atoms in the ground state. Physically, this range of states is interesting in that it provides strong interaction conditions that may lead to nonstandard phase transitions [3, 4]. The electrical conductivity, being an important parameter of the medium, carries information on its state. The most convenient method for studying kinetic plasma parameters is provided by linear response theory [5]. For the density and temperature ranges in which the multiparticle interaction nature should be taken into account, this theory gives a systematic description of interactions by invoking the mathematical apparatus of Green’s functions [6]. In comparison with the Kubo method [5], a more general approach based on a relevant statistical operator [7] substantially simplifies the calculations. In a number of papers (see, e.g., [8, 9]), it was demonstrated
that this approach has a wide range of applicability. It was also shown that the results of the approach coincide asymptotically with those of the Spitzer–Härm theory [10] (for a low density of unbound electrons) and of Ziman’s formula [11] (in the degenerate case). In order to determine the equilibrium and kinetic properties of a partially ionized plasma, it is necessar
