Mesh Refinement Based Simulation of Complex Plasma Dynamics during High Power Millimeter Wave Breakdown

The fluid-based simulation of high power millimeter(HPM) wave interaction with plasma is a computationally challenging problem. The complex phenomenon is a multi-physics and a multi-scale problem due to the involvement of coupled EM wave and plasma solvers with different space and time scales. The simulation requires a proper resolution in both space and time to accommodate the gradients in the fields as well as the plasma density, making it a computationally intensive problem. In this paper, we have implemented a mesh refinement based algorithm with selective refined grids in the desirable region with steep gradients in plasma density and electric(E) field. We have tested the algorithm on a test-bed problem, involving the formation of self-organized plasma filaments, for three different refinement factors (r_f = 2, 4, 8) and achieved a speedup of 4 - 100 compared to a serial implementation with uniform mesh without any refinement. We have investigated the dependence of speedup and accuracy on the refinement factor for different cases.