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Title: Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas

Abstract

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. __________________________________________________

Authors:
; ; ;
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1007180
Report Number(s):
PPPL-4599
TRN: US1101928
DOE Contract Number:  
DE-ACO2-09CHO11466
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASYMMETRY; ELECTRIC CURRENTS; ELECTRONS; FLUCTUATIONS; ORIGIN; PHYSICS; PLASMA; PRESSURE GRADIENTS; ROTATION; SAFETY; SHEAR; SYMMETRY BREAKING; TORQUE; TRANSPORT; TRAPPED ELECTRONS; TURBULENCE; Turbulence, Transport Phenomena, Tokamaks

Citation Formats

Wang, W. X., Hahm, T. S., Ethier, S., and Zakharov, L. E. Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas. United States: N. p., 2011. Web. doi:10.2172/1007180.
Wang, W. X., Hahm, T. S., Ethier, S., & Zakharov, L. E. Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas. United States. doi:10.2172/1007180.
Wang, W. X., Hahm, T. S., Ethier, S., and Zakharov, L. E. Mon . "Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas". United States. doi:10.2172/1007180. https://www.osti.gov/servlets/purl/1007180.
@article{osti_1007180,
title = {Trapped Electron Mode Turbulence Driven Intrinsic Rotation in Tokamak Plasmas},
author = {Wang, W. X. and Hahm, T. S. and Ethier, S. and Zakharov, L. E.},
abstractNote = {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. __________________________________________________},
doi = {10.2172/1007180},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2011},
month = {2}
}