Nonlinear saturation of collisionless trapped electron mode turbulence: Zonal flows and zonal density

2008 ◽  
Vol 15 (5) ◽  
pp. 055907 ◽  
Author(s):  
Jianying Lang ◽  
Scott E. Parker ◽  
Yang Chen
Keyword(s):  
Nonlinear Saturation ◽  
Zonal Flows ◽  
Electron Mode ◽  
Trapped Electron

scholarly journals Role of zonal flows in trapped electron mode turbulence through nonlinear gyrokinetic particle and continuum simulation

2009 ◽  
Vol 16 (5) ◽  
pp. 055906 ◽  
Author(s):  
D. R. Ernst ◽  
J. Lang ◽  
W. M. Nevins ◽  
M. Hoffman ◽  
Y. Chen ◽  
...  
Keyword(s):  
Zonal Flows ◽  
Electron Mode ◽  
Trapped Electron

Gyrokinetic simulation of collisionless trapped-electron mode turbulence

2005 ◽  
Vol 12 (7) ◽  
pp. 072309 ◽  
Author(s):  
Tilman Dannert ◽  
Frank Jenko
Keyword(s):  
Electron Mode ◽  
Trapped Electron

Study of turbulence in the high betap discharge using only RF heating on EAST

2022 ◽  
Author(s):  
shuyu Zheng ◽  
Debing Zhang ◽  
Erbing Xue ◽  
Limin Yu ◽  
Xianmei Zhang ◽  
...  
Keyword(s):  
Electron Collision ◽  
Rf Heating ◽  
Plasma Parameters ◽  
Equilibrium Data ◽  
Electron Mode ◽  
Radio Frequency Waves ◽  
Thermal Diffusivities ◽  
Gyrokinetic Simulations ◽  
Trapped Electron ◽  
Scale Length

Abstract High poloidal beta scenarios with favorable energy confinement (β_p~1.9, H_98y2~1.4) have been achieved on Experimental Advanced Superconducting Tokamak (EAST) using only radio frequency waves heating. Gyrokinetic simulations are carried out with experimental plasma parameters and tokamak equilibrium data of a typical high β_p discharge by the GTC code. Linear simulations show that electron temperature scale length and electron density scale length destabilize the turbulence, collision effects stabilize the turbulence, and the instability propagates in the electron diamagnetic direction. These indicate that the dominant instability in the core of high β_p plasma is collisionless trapped electron mode. Ion thermal diffusivities calculated by nonlinear gyrokinetic simulations are consistent with the experimental value, in which the electron collision effects play an important role. Further analyses show that instabilities with k_θ ρ_s>0.38 are suppressed by collision effects and collision effects reduce the radial correlation length of turbulence, resulting in the suppression of the turbulence.

scholarly journals Effect of the electron redistribution on the nonlinear saturation of Alfvén eigenmodes and the excitation of zonal flows

2020 ◽  
Vol 86 (3) ◽  
Author(s):  
A. Biancalani ◽  
A. Bottino ◽  
P. Lauber ◽  
A. Mishchenko ◽  
F. Vannini
Keyword(s):  
Magnetic Field ◽  
Zonal Flow ◽  
Large Aspect Ratio ◽  
Nonlinear Saturation ◽  
Energetic Ions ◽  
Electron Population ◽  
Zonal Flows ◽  
Particle In Cell ◽  
Alfven Eigenmodes ◽  
Reversed Shear

Numerical simulations of Alfvén modes driven by energetic particles are performed with the gyrokinetic (GK) global particle-in-cell code ORB5. A reversed shear equilibrium magnetic field is adopted. A simplified configuration with circular flux surfaces and large aspect ratio is considered. The nonlinear saturation of beta-induced Alfvén eigenmodes (BAE) is investigated. The roles of the wave–particle nonlinearity of the different species, i.e. thermal ions, electrons and energetic ions are described, in particular for their role in the saturation of the BAE and the generation of zonal flows. The nonlinear redistribution of the electron population is found to be important in increasing the BAE saturation level and the zonal flow amplitude.

Regulation of electron temperature gradient turbulence by zonal flows driven by trapped electron modes

2014 ◽  
Vol 21 (5) ◽  
pp. 052306 ◽  
Author(s):  
Y. Asahi ◽  
A. Ishizawa ◽  
T.-H. Watanabe ◽  
H. Tsutsui ◽  
S. Tsuji-Iio
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Zonal Flows ◽  
Electron Temperature Gradient ◽  
Trapped Electron

scholarly journals Intrinsic rotation drive by collisionless trapped electron mode turbulence

2016 ◽  
Vol 23 (4) ◽  
pp. 042309 ◽  
Author(s):  
Lu Wang ◽  
Shuitao Peng ◽  
P. H. Diamond
Keyword(s):  
Electron Mode ◽  
Trapped Electron
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