Characteristics of the H-mode pedestal in improved confinement scenarios in ASDEX Upgrade, DIII-D, JET and JT-60U

Maggi, C. F.*; Groebner, R. J.*; Oyama, Naoyuki; Sartori, R.*; Horton, L. D.*; Sips, A. C. C.*; Suttrop, W.*; ASDEX Upgrade Team; Leonard, T.*; Luce, T. C.*; Wade, M. R.*; DIII-D Team*; Kamada, Yutaka; Urano, Hajime; JT-60U Team; Andrew, Y.*; Giroud, C.*; Joffrin, E.*; la Luna, E. de.*; EFDA-JET Contributors* for the Pedestal and Edge Physics and the Steady State Operation Topical Grou*

Pedestal and global plasma parameters are compared in ELMy H-mode discharges from ASDEX Upgrade (AUG), DIII-D, JET and JT-60U. The increase in pedestal pressure (p) with power is continuous, reflecting the continuous transition from "standard H-mode" to "improved confinement scenario". In AUG improved H-modes p increases with power due to an increase of both pedestal top density and temperature. In DIII-D p increases primarily due to an increase of the pedestal temperature. In JT-60U high H-modes at = 6.5 and high the improved confinement is due to an increase of , while in reversed shear H-modes to an increase of . In JET hybrid discharges at 1.4 MA increases with power and due to an increase of . In all four tokamaks improved edge stability is correlated to increasing total and H98(y,2) increases with pedestal .