An asymptotic preserving scheme for the streamer simulation

In this work we describe the development of a robust simulator of the streamer phenomenon. A very common problem of computational plasma physics is the stability of the numerical scheme when the quasi-neutral regime is approached. Actually the stability condition may imply very tight time step constraints. We prove, both numerically and analytically, the good behavior of our approach when the system approaches the quasi-neutral regime. In particular, the semi-implicit method we employ requires mild time step restrictions to guarantee the stability. Some other properties such as the positivity of the scheme are investigated and a detailed review of the numerical implementation is included.