MODELING OF PLASMA MOMENTUM TRANSFERENCE TO SIDE-WALLS BY NEUTRAL PARTICLES

Monte Carlo modelling of plasma extinction by neutral particles requir es energy and momentum sinks to be determined with sufficient statisti cal significance. We focus on this aspect using calculations of an ide alized 1D plasma-gas interface with the Eirene code. A novel non-linea r version including self-collisions amongst neutral particles is also applied to admit gas viscosity. It emerges that statistically signific ant momentum losses often cannot practicably be determined, even at mo dest plasma temperatures (similar to 10 eV), using conventional collis ion-estimator techniques. Gas viscosity effects also tend to inhibit e xtraction of plasma momentum and hinder extinction. Certain possibilit ies to improve numerical methods are mentioned.