TIME-IMPLICIT FLUID SIMULATION OF COLLISIONAL PLASMAS

A one-dimensional algorithm for fluid simulation of interpenetrating multi-component plasmas, developed earlier for the collisionless case [1], is extended to include collisions between species. The finite-differenced fluid equations, including collision forces, are coupled with the Poisson equation to give time-implicit solutions, which are stable and accurate over a wide range of the time scale parameters ωpΔt and vcΔt (ωp is the plasma frequency, vc is a typical collision frequency, and Δt is the time step). In regions where ωpΔt ≪ 1 and vcΔt ≪ 1, electron dynamics and space-charge effects are resolved, while in regions where ωpΔt ≫ 1 and/or vcΔt ≫ 1, the ambipolar and/or diffusion models are recovered. Results of tests are presented, including ohmic heating, shocks with an interface between different fluids, colliding plasmas in which a region of interpenetrating fluids is created, and plasma shocks with separate electron and ion fluids. © 1992.