A Drift-Asymptotic scheme for a fluid description of plasmas in strong magnetic fields

Abstract

We present a numerical scheme for the ion Euler equations with Braginskii closure, in the quasi-neutral regime with an adiabatic electron response. The scheme is constructed with the aid of asymptotic-preserving (AP) techniques in order to avoid the singularity in the drift-limit. When the normalized gyro-radius tends to zero, the scheme performs the drift-limit numerically. Depending on the choice of the time step, it can resolve different physical phenomena, ranging from cyclotron motion to plasma transport or ion drifts. Since the development of AP-schemes for the Braginskii equations is in its exploratory phase, the plasma is assumed a three-dimensional slab in a uniform external magnetic field. We use the ion-temperature-gradient dispersion relation for the scheme’s verification. The promising results show that the method offers the possibility to adapt the numerical parameters to the desired resolution in the full fluid model, instead of switching to reduced models in the drift-limit.