Numerical simulations of interchange/tearing instabilities in 2D slab with a numerical model for edge plasma

Abstract

Numerical simulations of interchange/tearing instabilities in a 2D slab with a numerical model for edge plasma resistivity are carried out. Plasma outside the Last Closed Flux Surface (LCFS), or the scrape-off layer (SOL), can be characterized by open magnetic fields which terminate on the divertor plates in the outside. A numerical model with current diffusivity is developed to enforce a low-level saturated current profile in the SOL region as well as a current jump across the LCFS. The numerical simulations show that interchange modes can transform into tearing modes, as the current-interchange tearing modes which has been proposed by Zheng and Furukawa [Phys. Plasmas 17, 052508 (2010)]. An applicability of the model to the tokamak edge stability and ELM studies is discussed.