The effects of magnetic island on toroidal ion temperature gradient mode instability
ID:11 View Protection:PUBLIC Updated Time:2021-06-18 15:37:05 Hits:135 Poster Presentation

Start Time:2021-07-12 09:40 (Asia/Shanghai)

Duration:20min

Session:[E] E-poster [E] E-poster

Abstract
In this work, we have investigated the influences of static magnetic islands (MI) on electrostatic toroidal ion temperature gradient (ITG) mode. The ions are described by gyro-kinetic equations including MI, and adiabatic approximation is used for electrons. The eigen-equation for short-wavelength toroidal ITG mode in Fourier-ballooning representation is derived based on the quasi-neutrality condition, and eigen-value as well as mode structure is given. Both the flattening effects of MI on plasma pressure and   flow around MI separatrix are considered. it is found that when only considering the flattening effects of MI, ITG mode is stabilized as compared to the case without MI. While, the effective drive of toroidal ITG mode is enhanced when MI-scale   flow is also is considered, which even results in higher growth rate than the case without MI. This indicates that the   flow induced by MI destabilizes the toroidal ITG mode. Furthermore, when MI is taken into account, the radial profile of mode structures at MI phase ,   show different characteristic length, which can be clearly observed from the 2D contour plot of mode structure. This reveals that the mode structure is asymmetric about MI phase. Besides, the mode structure is unsmooth at the MI phase  , which may be caused by numerical integration problems.
Keywords
magnetic islands, toroidal ITG mode, growth rate, mode structure, gyro-kinetic equations
Speaker
Guodong Zhang
学生 HUST

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Contact:
Prof. Lu Wang

Email: luwang@hust.edu.cn

Prof. Zhongyong Chen

Email: zychen@hust.edu.cn

Jingwei Fu

Email: fujingwei@hust.edu.cn

Meiling Liang

Email: mlliang@hust.edu.cn

Wei Zheng

Email: zhengwei@hust.edu.cn