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Title: Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation

Abstract

Toroidal plasma flow driven by turbulent torque associated with nonlinear residual stress generation is shown to recover the observed key features of intrinsic rotation in experiments. Specifically, the turbulence-driven intrinsic rotation scales close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing empirical scalings obtained from a large experimental data base. The effect of magnetic shear on the symmetry breaking in the parallel wavenumber spectrum is identified. The origin of the current scaling is found to be the enhanced kll symmetry breaking induced by increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic rotation on the pressure gradient comes from the fact that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving the residual stress, are increased with the strength of the turbulence drives, which are R/LTe and R/Lne for the collisionless trapped electron mode (CTEM). Highlighted results also include robust radial pinches in toroidal flow, heat and particle transport driven by CTEM turbulence, which emerge "in phase", and are shown to play important roles in determining plasma profiles. Also discussed are experimental tests proposed to validate findingsmore » from these gyrokinetic simulations.« less

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1010968
Report Number(s):
PPPL-44608
TRN: US1102428
DOE Contract Number:  
DE-ACO2-09CH111466
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ELECTRIC CURRENTS; ORIGIN; PHYSICS; PLASMA; PRESSURE GRADIENTS; ROTATION; SAFETY; SHEAR; SYMMETRY BREAKING; TORQUE; TRANSPORT; TRAPPED ELECTRONS; TURBULENCE; Tokamaks, Turbulence, Transport Phenomena

Citation Formats

Wang, W. X., Hahm, T. S., Ethier, S., Rewoldt, G., Tang, W. M., Lee, W. W., and Diamond, P. H. Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation. United States: N. p., 2011. Web. doi:10.2172/1010968.
Wang, W. X., Hahm, T. S., Ethier, S., Rewoldt, G., Tang, W. M., Lee, W. W., & Diamond, P. H. Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation. United States. doi:10.2172/1010968.
Wang, W. X., Hahm, T. S., Ethier, S., Rewoldt, G., Tang, W. M., Lee, W. W., and Diamond, P. H. Sun . "Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation". United States. doi:10.2172/1010968. https://www.osti.gov/servlets/purl/1010968.
@article{osti_1010968,
title = {Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation},
author = {Wang, W. X. and Hahm, T. S. and Ethier, S. and Rewoldt, G. and Tang, W. M. and Lee, W. W. and Diamond, P. H.},
abstractNote = {Toroidal plasma flow driven by turbulent torque associated with nonlinear residual stress generation is shown to recover the observed key features of intrinsic rotation in experiments. Specifically, the turbulence-driven intrinsic rotation scales close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing empirical scalings obtained from a large experimental data base. The effect of magnetic shear on the symmetry breaking in the parallel wavenumber spectrum is identified. The origin of the current scaling is found to be the enhanced kll symmetry breaking induced by increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic rotation on the pressure gradient comes from the fact that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving the residual stress, are increased with the strength of the turbulence drives, which are R/LTe and R/Lne for the collisionless trapped electron mode (CTEM). Highlighted results also include robust radial pinches in toroidal flow, heat and particle transport driven by CTEM turbulence, which emerge "in phase", and are shown to play important roles in determining plasma profiles. Also discussed are experimental tests proposed to validate findings from these gyrokinetic simulations.},
doi = {10.2172/1010968},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2011},
month = {3}
}