Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas

Wang, W. X. ; Hahm, T. S. ; Ethier, S. ; Zakharov, L. E.

关键词: ASYMMETRY;    ELECTRIC CURRENTS;    ELECTRONS;    FLUCTUATIONS;    ORIGIN;    PHYSICS;    PLASMA;    PRESSURE GRADIENTS;    ROTATION;    SAFETY;    SHEAR;    SYMMETRY BREAKING;    TORQUE;    TRANSPORT;    TRAPPED ELECTRONS;    TURBULENCE Turbulence;    Transport Phenomena;    Tokamaks;   

DOI  :  10.2172/1007180
RP-ID  :  PPPL-4599
PID  :  OSTI ID: 1007180
Others  :  TRN: US1101928

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

Recent progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported with emphasis on electron thermal transport dominated regimes. The turbulence driven intrinsic torque associated with nonlinear residual stress generation by the fluctuation intensity and the intensity gradient in the presence of zonal flow shear induced asymmetry in the parallel wavenumber spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current. These results qualitatively reproduce empirical scalings of intrinsic rotation observed in various experiments. The origin of current scaling is found to be due to enhanced kll symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic torque on pressure gradient is that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving residual stress, increase with the strength of turbulence drive, which is R0/LTe and R0/Lne for the trapped electron mode. __________________________________________________