Eur. Phys. J. D 29, 379-389 (2004)
https://doi.org/10.1140/epjd/e2004-00036-0

Fokker-Planck modeling for particle slowing down and thermalization in a Maxwellian plasma

¹ Department of Mathematics and Statistics, Texas Tech University, Lubbock, Texas 79409-1042, USA
² DIENCA, University of Bologna, Via dei colli 16, 40136 Bologna, Italy

Corresponding author: ^a federico.rocchi@mail.ing.unibo.it

Received: 25 July 2003
Revised: 1 December 2003
Published online: 16 March 2004

Abstract

In this paper the Fokker-Planck equation, which takes into account the medium absorption and the Maxwellian behavior of the field particles at low energy for Coulomb interactions is obtained. The analytical solution of the stationary distribution function is obtained in both angle and velocity variables. In particular the electron distribution for electron-ion collisions has been obtained using this diffusion approximation for beam and isotropic sources. If the absorption is neglected the solution recovers the classical stationary Maxwell distribution. For low absorption rates the solution shows a typical slowing down spectrum for high energy and a Maxwellian-like distribution at thermal energy. For moderate and high absorption rates the test particles do not reach the thermal equilibrium and the Maxwell distribution at low energies does not appear.