Edge Transport Barrier Models for Simulating H-Mode Operation Scenarios in DEMO with Integrated Plasma Transport Code TOTAL

Abstract

Edge transport barrier (ETB) models are developed and introduced into an integrated transport code TOTAL. The transitions between L-mode and H-mode are triggered by comparing the net heating power with the threshold powers. At the L to H transition, quick reduction in transport in the pedestal region causes back transition due to reduced net heating power and then gradual change in the transport in the pedestal region is needed. The pedestal pressure is adjusted to the value predicted by an empirical scaling. Three models, the PID control model, the ELM model, and the empirical continuous ELM model, are compared for the pedestal pressure control. The control is possible in all of three models but it is observed that larger pellet injection is needed to increase the density and a lower pedestal density is obtained in the ELM model. During tungsten injection, the pedestal pressure is well controlled in the empirical continuous ELM model and in the PID control model.