Work

Gyrokinetic simulation of turbulence under lower hybrid wave and electron cyclotron wave combined heating on EAST

Year: 2024

Type: article

Abstract: On the Experimental Advanced Superconducting Tokamak (EAST), the electron cyclotron wave (ECW) and lower hybrid wave (LHW) are actively used to achieve a high-performance plasma. Turbulence associated with the combined heating experiment is studied numerically based on the gyrokinetic toroidal code (GTC). The linear simulation results show that the unstable mode peaks at $k_{\theta }\rho _{s}\approx 0.65$ and $k_{\theta }\rho _{s}\approx 1.42$ . Meanwhile, all of the frequencies of these instabilities are positive, which suggests that the collisionless trapped electron mode (CTEM) is the dominant instability. In the process of nonlinear simulations, a higher transport level is locally achieved during the two waves combined heating due to a formation of a steeper electron temperature gradient. In addition, a low-frequency geodesic acoustic mode (GAM) is observed in the nonlinear stage. Effects of the electron beta, the dimensionless ratio of $T_e/T_i$ and $R/L_{T_e}$ on the growth rate of instability, are also discussed in the paper.

Source: Journal of Plasma Physics

DOI: 10.1017/s0022377824000874

Authors: Zhengyao Xiao, Xinxia Li, Qi Zhong, Miaohui Li

Institutions: University of South China, Zhejiang University, Chinese Academy of Sciences, Institute of Plasma Physics

Language: English

Topic: Magnetic confinement fusion research

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,450

Funders: National Natural Science Foundation of China, Chinese Academy of Sciences, Institute of Plasma Physics, Chinese Academy of Sciences