Density pump-out compensation during type-I edge localized mode control experiments with n = 1 perturbation fields on JET

Experiments to balance the density pump-out effect during edge localized mode (ELM) control through the application of an n = 1 magnetic perturbation in type-I H-mode plasmas at JET are presented, describing the effect on Te, ne and pe profiles. Reference discharges during H-mode with and without resonant magnetic perturbation are first considered, and compared with results obtained in previous work. Pellet and gas injection are the two applied techniques; on the basis of previous experience, various particle fuelling rates have been tested on two different divertor configurations, finding those for which the compensation takes place. In terms of plasma confinement, while core pressure is found to be almost unvaried with the particle fuelling, the edge pressure pedestal improves towards the value obtained during the H-mode without the application of the magnetic perturbation. The edge stability analysis shows that the mitigated edge plasma even with the addition of particle fuelling is in the stable region against the type-I ELM triggering peeling–ballooning modes.