Species dependence of the impurity injection induced poloidal flow and magnetic island rotation in a tokamak

TL;DR

This paper investigates how impurity species affect poloidal flow and magnetic island rotation in tokamaks, revealing that impurity injection influences local plasmoid formation and electromagnetic torque, which in turn drive island dynamics.

Contribution

It demonstrates through resistive MHD simulations that impurity species determine poloidal flow direction and magnetic island rotation via local plasmoid formation and electromagnetic torque effects.

Findings

Impurity poloidal flow depends on impurity species.

Magnetic island rotation is driven by electromagnetic torque.

Local plasmoid formation influences impurity flow.

Abstract

Recent experiments have demonstrated the species dependence of the impurity poloidal drift direction along with the magnetic island rotation in the poloidal plane. Our resistive MHD simulations have reproduced such a dependence of the impurity poloidal flow, which is found mainly determined by a local plasmoid formation due to the impurity injection. The synchronized magnetic island rotation is dominantly driven by the electromagnetic torque produced by the impurity radiation primarily through the modification to the axisymmetric components of current density.