Numerical solution of a ionic Fokker-Planck equation with electronic temperature

We describe a numerical scheme Sor dealing with an ion electron/collision operator of the Fokker-Planck type; for that purpose, we introduce the notion of entropic average of two positive quantities. This scheme has the property to be entropic in the sense of Boltzmann's H theorem under a CFL criteria. Moreover; we prove that the solution converges when the time grows, towards a unique Maxwellian equilibrium state. (C) Academie des Sciences/Elsevier, Paris.