Effects of Collisional Zonal Flow Damping on Turbulent Transport

Abstract

Results from 3D global gyrokinetic particle simulations of ion-temperature-gradient driven microturbulence in a toroidal plasma show that the ion thermal transport level in the interior region exhibits significant dependence on the ion-ion collision frequency even in regimes where the instabilities are collisionless. This is identified as arising from the Coulomb collisional damping of turbulence-generated zonal flows.