Basic microscopic plasma physics unified and simplified by N-body classical mechanics

Dominique Escande (1) , Fabrice Doveil (1) , Yves Elskens (1)

1 PIIM - Physique des interactions ioniques et moléculaires

One considers an infinite plasma made up of the periodic replication of $N$ electrons coupled by Coulomb forces in a volume $L^3$ with a neutralizing ionic background. Using Fourier and Laplace transforms, a rigorous fundamental equation is derived for the electrostatic potential. A first coarse graining of this equation reveals the potential to be the sum of the screened Coulomb potentials of the individual particles. A second coarse graining yields the classical Vlasovian expression including initial conditions in Landau contour calculations of Langmuir wave growth or damping. Using the screened potential, the collisional diffusion coefficient is computed by a convergent expression including the deflections for all impact parameters. Screening and collisional transport are found to be two related aspects of the repulsive deflections of electrons. The theory is extended to accommodate a correct description of trapping or chaos due to Langmuir waves. In the linear regime, the amplitude of such a wave is found to be ruled by Landau growth or damping and by spontaneous emission.

Domaines: Physique des plasmas [physics.plasm-ph]

Dominique Escande, Fabrice Doveil, Yves Elskens. Basic microscopic plasma physics unified and simplified by N-body classical mechanics. 2012. ⟨hal-00725424v1⟩