Energy conservation tests of a coupled kinetic plasma–kinetic neutral transport code

Abstract

An approach to coupling two kinetic particle codes for the simulation of neutral–plasma interactions in magnetic fusion devices is described. The behavior of the neutral atoms and molecules is modeled with a Monte Carlo code. The plasma species are simulated with a particle-in-cell code that integrates the guiding center equations of motion and computes a self-consistent electric field. The coupling algorithm is designed to conserve mass in the neutral–plasma exchanges to statistical accuracy. Although energy is not fully conserved due to the velocity dependence of the charge exchange cross section and the kinetic character of both species, the impact of this non-conservation on the overall simulation is negligible.