Collisionless Drift Waves Ranging from Current-Driven, Shear-Modified, and Electron-Temperature-Gradient Modes

2010 ◽  
Vol 51 (6) ◽  
pp. 537-545 ◽  
Author(s):  
R. Hatakeyama ◽  
C. Moon ◽  
S. Tamura ◽  
T. Kaneko
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Drift Waves ◽  
Electron Temperature Gradient

scholarly journals Excitation of zonal flow by the modulational instability in electron temperature gradient driven turbulence

2008 ◽  
Vol 74 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Yu. A. ZALIZNYAK ◽  
A. I. YAKIMENKO ◽  
V. M. LASHKIN
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Large Scale ◽  
Modulational Instability ◽  
Zonal Flow ◽  
Finite Amplitude ◽  
Small Scale ◽  
Drift Waves ◽  
Zonal Flows ◽  
Electron Temperature Gradient

AbstractThe generation of large-scale zonal flows by small-scale electrostatic drift waves in electron temperature gradient driven turbulence model is considered. The generation mechanism is based on the modulational instability of a finite amplitude monochromatic drift wave. The threshold and growth rate of the instability as well as the optimal spatial scale of zonal flow are obtained.

Effect of electron temperature gradient on the modulational instability of drift waves and anomalous transport due to drift-wave turbulence

1988 ◽  
Vol 40 (2) ◽  
pp. 253-262 ◽  
Author(s):  
D. Majumdar
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Nonlinear Evolution ◽  
Modulational Instability ◽  
Wave Turbulence ◽  
Drift Waves ◽  
Multiple Time ◽  
Third Order ◽  
Drift Wave Turbulence ◽  
Electron Temperature Gradient

A nonlinear drift-mode equation including the effect of an electron-temperature gradient has been derived. To discuss modulational instability, we have obtained a nonlinear evolution equation for the drift mode from a third-order secularity-elimination condition using a multiple time- and space-scales technique. The effect of localized structure on the transport process has been investigated.

Ion scale nonlinear interaction triggered by disparate scale electron temperature gradient mode

2015 ◽  
Vol 22 (5) ◽  
pp. 052301
Author(s):  
Chanho Moon ◽  
Tatsuya Kobayashi ◽  
Kimitaka Itoh ◽  
Rikizo Hatakeyama ◽  
Toshiro Kaneko
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Nonlinear Interaction ◽  
Electron Temperature Gradient ◽  
Gradient Mode

Comparison of dynamical features between the fast H-L and the H-I-L transition for EAST RF-heated plasmas

2021 ◽  
Author(s):  
Liang Chen ◽  
Guo Sheng Xu ◽  
Linming Shao ◽  
Wei Gao ◽  
Yifeng Wang ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Intermediate Phase ◽  
Critical Role ◽  
Potential Gradient ◽  
Flow Shear ◽  
Important Distinction ◽  
Radial Gradient ◽  
Electron Temperature Gradient ◽  
Dynamical Features

Abstract In this paper, a comparison of dynamical features between the fast H-L and the H-I-L transition, which can be identified by the intermediate phase, or ‘I-phase’, has been made for radio-frequency (RF) heated deuterium plasmas in EAST. The fast H-L transition is characterized by a rapid release of stored energy during the transition transient, while the H-I-L transition exhibits a ‘soft’ H-mode termination. One important distinction between the transitions has been observed by dedicated probe measurements slightly inside the separatrix, with respect to the radial gradient of the floating potential, which corresponds to the E×B flow and/or the electron temperature gradient. The potential gradient inside the separatrix oscillates and persists during the stationary I-phase, and shows a larger amplitude than that before the fast H-L transition. The reduction of the gradient leads to the final transition to the L-mode for both the fast H-L and the H-I-L transition. These findings indicate that the mean E×B flow shear and/or edge electron temperature gradient play a critical role underlying the H-L transition physics. In addition, the back transition in EAST is found to be sensitive to magnetic configuration, where the vertical configuration, i.e., inner strike-point located at vertical target, favours access to the H-I-L transition, while the horizontal shape facilitates achievement of the fast H-L transition. The divertor recycling level normalized to electron density is higher before the fast H-L transition, as compared to that before the I-phase, which strongly suggest that the density of the recycled neutrals is an important ingredient in determining the back transition behaviour.

Electron temperature gradient turbulence induced energy flux in the large volume plasma device

2019 ◽  
Vol 26 (5) ◽  
pp. 052303
Author(s):  
Prabhakar Srivastav ◽  
Rameswar Singh ◽  
L. M. Awasthi ◽  
A. K. Sanyasi ◽  
P. K. Srivastava ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Electron Temperature ◽  
Energy Flux ◽  
Large Volume ◽  
Electron Temperature Gradient ◽  
Plasma Device
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