Pedestal Modelling Based on Ideal MHD and Gyrokinetic Stability Analyses on MAST and JET Plasmas
The H-mode pressure pedestal is crucial for the confinement of a tokamak fusion device. In order to predict the height of the pedestal, we need to understand the instabilities controlling the pedestal evolution. Pedestal performance has been successfully predicted for several current tokamaks using the EPED model which combines pedestal pressure gradient limiting Kinetic Ballooning Modes (KBM) with pedestal top pressure limiting peeling-ballooning modes to produce a prediction for the pedestal width and height. In this paper, we exploit high resolution diagnosis of pedestal profiles from Type I ELM cycles on MAST and JET to perform MHD and gyrokinetic stability analyses that allow us to test rigorously the ideas behind the EPED model.