Hybrid Particle-Fluid Modeling of Plasmas

There are many interesting physical processes which involve the generation of high density plasmas in large volumes. However, when modeling these systems numerically, the large densities and volumes present a significant computational challenge. One technique for modeling plasma physics, the particle in cell (PIC) approach, is very accurate but requires increasing computation time and numerical resolution as the density of the plasma grows. In this paper we present a new technique for mitigating the extreme computational load as the plasma density grows by combining existing PIC methods with a dielectric fluid approach. By using both descriptions in a hybrid particle-fluid model, we now can probe the physics in large volume, high density regions. The hybrid method also provides a smooth transition as the plasma density increases and the ionization fraction grows to values that are well described by the fluid description alone. We present the hybrid technique and demonstrate the validity of the physical model by benchmarking against a simple example with an analytic solution.