ELMs and the H-mode pedestal in NSTX

Evolution of the H-mode edge pedestal between ELMs

The evolution of edge pedestal parameters between edge-localized modes (ELMs) is analyzed for an H-mode DIII-D [J Luxon, Nucl. Fusion 42, 612 (2002)] discharge. Experimental data are averaged over the same sub-intervals between successive ELMs to develop data that characterize the evolution of density, temperature, rotation velocities, etc. over the interval between ELMs. These data are interpr...

Varying the pre-discharge lithium wall coatings to alter the characteristics of the ELM-free H-mode pedestal in NSTX

The Role of Neutrals in H–mode Pedestal Formation

Resonant magnetic perturbation effects on pedestal structure and ELMs

The plasma transport processes by which externally applied resonant magnetic field perturbations (RMPs) mitigate or suppress edge localized modes (ELMs) in low collisionality tokamak H-mode plasmas are explored. Experimental data from DIII-D indicates the dominant RMP-induced transport occurs at the pedestal top where electron temperature gradient scale lengths increase up to 3 times more than ...

Global gyrokinetic simulations of the H-mode tokamak edge pedestal

Global gyrokinetic simulations of DIII-D H-mode edge pedestal show two types of instabilities may exist approaching the onset of edge localized modes: an intermediate-n, high frequency mode which we identify as the “kinetic peeling ballooning mode (KPBM),” and a high-n, low frequency mode. Our previous study [W. Wan et al., Phys. Rev. Lett. 109, 185004 (2012)] has shown that when the safety fac...