Finite-grid instability in quasineutral hybrid simulations
Hybrid simulation models some physical plasma species by particles while the others by fluids. Sometimes this procedure offers very useful insight into physical phenomena, especially in the case of long time scales. However, the influence of the finite grid upon the simulation (numerical instability) has not yet been thouroughly investigated. Now the linear stability, the nonlinear heating, and the saturation of quasineutral hybrid simulation are investigated with respect to the finite computational spatial grid. Cold ion distribution with no drift relative to the grid is stable whereas finite ion temperature or drift are destabilizing. Warm and cold plasma dispersion relations are evaluated taking into account the role of drifting to show ameliorating effects of the nearest particle weighting or linear (cloud in cell) weighting. Relevant applications to laser produced plasmas are promising.
scientific article; zbMATH DE number 758621