  The electric potential is an essential quantity for the confinement process
of tokamak plasmas, with important impact on the performances of fusion
reactors. Understanding its evolution in the peripheral region - the part of
the plasma interacting with the wall of the device - is of crucial importance,
since it governs the boundary conditions for the burning core plasma. The aim
of the present paper is to study numerically the evolution of the electric
potential in this peripheral plasma region. In particular, we are interested in
introducing an efficient Asymptotic-Preserving numerical scheme capable to cope
with the strong anisotropy of the problem as well as the non-linear boundary
conditions, and this with no huge computational costs. This work constitutes
the numerical follow-up of the more mathematical paper by C. Negulescu, A.
Nouri, Ph. Ghendrih, Y. Sarazin, "Existence and uniqueness of the electric
potential profile in the edge of tokamak plasmas when constrained by the
plasma-wall boundary physics".
