Exploring novel electromagnetic algorithms for efficient Hybrid Fluid-Kinetic Multiphysics Simulations

In particle-based fluid-kinetic plasma simulations¹, an electromagnetic field solver is coupled to the particles via a mesh. Explicit finite-difference time-domain (FDTD) methods solve Maxwell's equations and require very small time steps when high-resolution meshes are used. Long time-scale simulations might require 10⁵-10⁷ time steps in order to reach the hydrodynamic time of interest. A critical area of research is to accelerate these computations using GPU hardware. The use of implicit methods generally requires additional operations to solve banded matrices and has more complex algorithm design, but benefits by being unconditionally stable and unrestricted by the need to resolve the speed of light on the mesh. This enables larger time steps and shorter computation times. The fundamental locally one dimensional complying divergence (FLOD-CD-FDTD²) method is an unconditionally stable semi-implicit noniterative method. We report on our efforts to test this and similar algorithms for accuracy, efficiency, memory use, and how well they can be accelerated and parallelized. Our goal is to stably and accurately achieve very long simulation times for ICF, HEDP, and MFE applications.