Geometric effect on profile flattening of magnetic island in Tokamak

Abstract

Magnetic island is manifestation of magnetic field reconnection by tearing mode, particularly, neoclassical tearing mode in tokamaks. Considering that neoclassical tearing mode has been observed to degrade plasma confinement and even cause plasma disruption, understanding its physics is getting more and more important in moving toward stable operation of Tokamak. In this research we carried out electrostatic gyrokinetic turbulence simulations with fixed magnetic island using GENE ( Gyrokinetic Electromagnetic Numerical Experiment ). We present effect of geometric parameters on profile flattening inside the magnetic island and discuss its implication and underlying physics. This work has been supported by National Research Foundation under basic research program of nuclear fusion, NRF-2019M1A7A1A03088462 and NRF-2017M1A7A03072766.