Two-dimensional particle simulation of the flow control in SOL and divertor plasmas

Two-dimensional (2D) particle simulations are performed by using PARASOL code to study the flow control in SOL and divertor plasmas in a double-null magnetic configuration with the separatrix. The divertor asymmetry is induced by the drift effect. The E×B drift (VE×B) and the diamagnetic drift (Vdia) work to induce the asymmetric flow in different ways with each other. The condition of 2D sheath formation is developed. Different influences of VE×B and Vdia on the asymmetric flow generation are clearly explained. Effects of divertor biasing and gas puffing on the flow are investigated with PARASOL simulations. The divertor asymmetry can be controlled by both the biasing and the gas puffing. It is found that the control of the drifts is essential to control the flow and the asymmetry.