An Advanced EM-Plasma Simulator Based on the DGTD Algorithm With Dynamic Adaptation and Multirate Time Integration Techniques

In a numerical simulation of the interactions between high-intensity electromagnetic (EM) waves and plasma fluids, a good numerical resolution is required for all the physical quantities of interest, especially the plasma density distribution around the edge of the plasma bulk. Since the plasma formation and evolution is a dynamic process, it is difficult to predetermine the appropriate resolution at a given location. In this paper, we describe a discontinuous Galerkin time-domain (DGTD) based dynamic adaptation algorithm, which is able to adjust either the local mesh size or the local polynomial order in real time of a simulation to provide a sufficient numerical resolution of the physics while keeping the total computational cost low. To alleviate the constraint of the time step size of an explicit time integrator, a multirate time integration method is employed to advance the physics in time, which permits the application of different time step sizes in elements with different sizes or polynomial orders. With these techniques, the DGTD simulation of EM-plasma interactions can achieve a good accuracy and high efficiency.