Modelling of ETG turbulent transport in the TCV pedestal

Results of the first gyrokinetic simulations of the TCV pedestal are presented. Two discharges at varying levels of gas puffing are considered as input parameters for the local GENE simulations. Linear and nonlinear simulations are carried out for electron scale turbulence to determine the role of the electron temperature gradient (ETG) mode in the pedestal transport. The heat flux associated with ETG is found to be negligible compared to the total experimental electron heat flux at lower gas puff. At higher gas puff, computed heat flux was find to account for experimental values, demonstrating the importance of the ETG-driven transport in this case. Additional simulations are carried out with modified density profiles to investigate the difference between the two discharges. The change of the electron heat flux is found to be associated with the transition from slab- to toroidal-ETG due to the reduction of the normalized density gradient in the pedestal at the higher gas puffing.