Asymptotic preserving finite-volume method for fluid models in low-temperature partially-magnetized plasma applications involving instabilities.

Multi-fluid plasma models are able to represent the scale disparity between the different species within plasmas while being theoretically less expensive than kinetic approaches. In a previous work, we have demonstrated the capability of advanced finite-volume methods for electrostatic multi-fluid models to simulate the onset and physics of instabilities in magnetized partially-ionized plasma at low pressure in the presence of sheaths. Nevertheless, stability constraints, which typically imply that the time step must be lower than the inverse of the electron plasma frequency and that the mesh size should be below the Debye length, are extremely restrictive and prevent finite-volume method from significantly outperforming PIC methods in terms of computational cost. We propose a so-called asymptotic preserving scheme that remains stable even when these conditions are not met. As a result, this approach allows for a significant reduction of the simulation time and fully benefits from the potential of fluid methods. The results are compared to reference PIC simulation obtained via the LPPic code and other fluid models found in the literature.