We report on a numerical analysis of luminescence signals observed during pellet injection into magnetically confined plasmas. Data from the ASDEX tokamak and the Wendelstein W7-AS advanced stellarator are considered in the form of a comparative study. We investigate how far the safety factor q and other plasma parameters influence the luminescence signals. Thus, we try to clarify the validity of the so-called neutral gas shielding model and an extension of it that takes into account the influence of resonant surfaces on the ablation process. Resonant values play only a minor role in the appearance of minima in the luminescence signals.
Modelling of pellet ablation in additionally heated plasmas