Characteristics of H-mode Pedestals in Improved Confinement Regimes in DIII-D

The characteristics of H-mode pedestals in improved confinement regimes are studied and compared to conventional ELMing H-mode discharges in DIII-D. These improved regimes include VH-mode, hybrid H-mode and Advanced Tokamak (AT) discharges. Initial results of this study show that across all regimes, 1)~confinement improves as the pedestal electron beta-poloidal [beta-pol$_{e(ped)}$] increases; 2)~the global beta-poloidal of the plasma is linearly related to beta-pol$_{e(ped)}$; and 3)~the scale length for the electron pedestal pressure profile is of similar magnitude. Thus, the initial results of this study show that there is a continuum of pedestal parameters with various confinement regimes falling within this continuum. In other words, the improved confinement in these regimes does not result from a dramatic change in pedestal characteristics.