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Since it is uncertain if ITER operation is compatible with type-l edge localized modes (ELMS), the study of alternative ELM regimes is an urgent issue. This paper reports on experiments on JET aiming to find scenarios with small ELMS and good confinement, such as the type-II ELMS in ASDEX Upgrade, the enhanced D-alpha H-mode in Alcator C-mod or the grassy ELMS in JT-60U. The study includes shape variations, especially the closeness to a double-null configuration, variations of q(95), density and beta poloidal. H-mode pedestals without type-I ELMs have been observed only at the lowest currents (

The characteristics of the H-mode density pedestal are determined by a balance between two competing processes ­ plasma transport across the region and neutral particle fuelling of the edge plasma. Identifying the relative role of plasma physics vs atomic physics of neutral fuelling is important for advancing our understanding of H-mode pedestal. A dimensionless identity technique can be used for this purpose, which is based on the fundamental fact that conservation of dimensionless plasma parameters (collisionality n*, normalized plasma pressure b, and normalized gyroradius n*) leads to invariance of plasma physics with respect to changes of dimensional parameters (plasma density ne and temperature Te). A first experiment applying this technique to tokamak pedestal studies was carried out on the Alcator C-Mod and DIII-D tokamaks. In this paper we compare the results of that experiment with the results of another experiment on JET and C-Mod and present a preliminary analysis of neutral fuelling in the discharges under consideration on all three tokamaks with the one-dimensional kinetic neutral transport code KN1D.