Nonlinear transfer in heated L-modes approaching the L–H transition threshold in Alcator C-Mod
Author(s)Cziegler, I.; Tynan, G.R.; Diamond, P.H.; Hughes, J.W.; Hubbard, Amanda E; Irby, James Henderson; Terry, James L; ... Show more Show less
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Nonlinear transfer processes between large-scale edge flows and the ambient broadband fluctuations have been shown to play a significant role in the dynamics of edge turbulence, including spreading power from coherent modes and suppressing turbulence at the formation of edge transport barriers. In order to predict thresholds of confinement regimes, both the transition dynamics and the parametric dependence of the nonlinear energy transfer must be studied. Since the expected flow damping terms depend on ion collision rates and local safety factors, recent experiments aimed also to explore the nonlinear drive at various values of the plasma current, density and amount of auxiliary heating. Nonlinear interactions between zonal flows and turbulence in L-mode are estimated using bispectral as well as time-resolved methods based on gas-puff-imaging in Alcator C-Mod .
DepartmentMassachusetts Institute of Technology. Plasma Science and Fusion Center
Cziegler, I. et al. “Nonlinear Transfer in Heated L-Modes Approaching the L–H Transition Threshold in Alcator C-Mod.” Nuclear Fusion 55, 8 (June 2015): 083007. © 2015 IAEA, Vienna
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