Multiscale Methods and Numerical Strategies for Magnetized Plasma Models

by Chang Yang

Tuesday Jul 8, 2025, 11:15 AM → 12:15 PM Europe/Paris

The aim of this work is to introduce a numerical method to cope with the multiscale nature of confined plasma physics. These investigations are focused on fluid plasma description under large magnetic field. The difficulties in this context stem from intense magnetization of the plasma, inducing a severe anisotropy, possible quasi-neutrality breakdowns, which may occur locally in the plasma and, eventually, the drift regime which prevails for the description of the electrons. These characteristics bring small parameters compared to the scale of the studied device, the linear plasma device HIT-PSI. For numerical resolutions, we will construct asymptotic-preserving (AP) schemes by employing appropriate explicit-implicit temporal discretization methods and introducing necessary auxiliary variables, ensuring numerical stability across scales. However, AP schemes also increase computational costs, particularly by introducing more complex block-structured linear systems. To address this, we will first study a simplified toy model to develop corresponding block preconditioning methods, aiming to accelerate numerical solving efficiency.