摘要
Characteristics of the magnetic-island-induced ion temperature gradient （MITG） mode are studied through gyrofluid simulations in the slab geometry, focusing on the effects of Landau damping, equilibrium magnetic shear （EMS）, and pressure flattening. It is shown that the magnetic island may enhance the Landau damping of the system by inducing the radial magnetic field. Moreover, the radial eigenmode numbers of most MITG poloidal harmonics are increased by the magnetic island so that the MITG mode is destabilized in the low EMS regime. In addition, the pressure profile flattening effect inside a magnetic island hardly affects the growth of the whole MITG mode, while it has different local effects near the O-point and the X-point regions. In comparison with the non-zero-order perturbations, only the quasi-linear flattening effect due to the zonal pressure is the effective component to impact the growth rate of the mode.
Characteristics of the magnetic-island-induced ion temperature gradient （MITG） mode are studied through gyrofluid simulations in the slab geometry, focusing on the effects of Landau damping, equilibrium magnetic shear （EMS）, and pressure flattening. It is shown that the magnetic island may enhance the Landau damping of the system by inducing the radial magnetic field. Moreover, the radial eigenmode numbers of most MITG poloidal harmonics are increased by the magnetic island so that the MITG mode is destabilized in the low EMS regime. In addition, the pressure profile flattening effect inside a magnetic island hardly affects the growth of the whole MITG mode, while it has different local effects near the O-point and the X-point regions. In comparison with the non-zero-order perturbations, only the quasi-linear flattening effect due to the zonal pressure is the effective component to impact the growth rate of the mode.
作者
Wei WANG
Zhengxiong WANG
Jiquan LI
Yasuaki KISHIMOTO
Jiaqi DONG
Shu ZHENG
王玮;王正汹;李继全;Yasuaki KISHIMOTO;董家齐;郑殊(Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics,Dalian University of Technology;Southwestern Institute of Physics;Graduate School of Energy Science, Kyoto University;Institute for Fusion Theory and Simulation, Zhejiang University)
基金
supported by National Natural Science Foundation of China with Nos.11305027,11322549 and 11675038
National Magnetic Confinement Fusion Science Program of China with No.2014GB124000
partly supported by the Fundamental Research Funds for the Central Universities with Grant No.DUT15YQ103
