scholarly journals The Transition to Collisionless Ion-temperature-gradient-driven Plasma Turbulence: A Dynamical Systems Approach

2004 ◽  
Author(s):  
R.A. Kolesnikov ◽  
J.A. Krommes
Keyword(s):  
Dynamical Systems ◽  
Temperature Gradient ◽  
Systems Approach ◽  
Plasma Turbulence ◽  
Ion Temperature ◽  
Ion Temperature Gradient

scholarly journals Nonlinear electromagnetic interplay between fast ions and ion-temperature-gradient plasma turbulence

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
A. Di Siena ◽  
T. Görler ◽  
E. Poli ◽  
A. Bañón Navarro ◽  
A. Biancalani ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Turbulent Transport ◽  
Turbulence Models ◽  
Zonal Flow ◽  
Plasma Turbulence ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Beneficial Effects ◽  
Scale Turbulence ◽  
Flow Activity

In strong electromagnetic regimes, gyrokinetic simulations have linked a substantial ion-scale turbulence stabilization to the presence of supra-thermal particles, capturing qualitatively well the experimental observations in different devices worldwide. An explanation for the underlying physical mechanism responsible for the fast-ion-induced turbulent transport reduction observed in the numerical simulations has been proposed only recently by Di Siena et al. (Nucl. Fusion, vol. 59, 2019, p. 124001; Nucl. Fusion, vol. 60, 2020, p. 089501). It involves a nonlinear cross-scale coupling (nonlinear interaction involving different modes at different wavenumbers) between ion-temperature-gradient and marginally stable Alfvén eigenmodes, which in turn increases zonal flow activity. In view of an optimization of this turbulence-stabilizing effect, the key parameters controlling the nonlinear cross-scale coupling are here identified. At the same time, these findings provide useful insights for reduced-turbulence models and integrative approaches, which might be trained on the results presented in this paper to grasp the underlying physics and the parameter scaling of the beneficial effects of fast particles on plasma turbulence.

scholarly journals Enstrophy non-conservation and the forward cascade of energy in two-dimensional electrostatic magnetized plasma turbulence

2020 ◽  
Vol 86 (4) ◽  
Author(s):  
G. G. Plunk
Keyword(s):  
Temperature Gradient ◽  
Plasma Turbulence ◽  
Magnetized Plasma ◽  
Larmor Radius ◽  
Ion Temperature ◽  
Fluid System ◽  
Ion Temperature Gradient ◽  
Zonal Flows ◽  
Electron Temperature Gradient ◽  
Enstrophy Cascade

A fluid system is derived to describe electrostatic magnetized plasma turbulence at scales somewhat larger than the Larmor radius of a given species. It is related to the Hasegawa–Mima equation, but does not conserve enstrophy, and, as a result, exhibits a forward cascade of energy, to small scales. The inertial-range energy spectrum is argued to be shallower than a $-11/3$ power law, as compared to the $-5$ law of the Hasegawa–Mima enstrophy cascade. This property, confirmed here by direct numerical simulations of the fluid system, may help explain the fluctuation spectrum observed in gyrokinetic simulations of streamer-dominated electron-temperature-gradient driven turbulence (Plunk et al., Phys. Rev. Lett., vol. 122, 2019, 035002), and also possibly some cases of ion-temperature-gradient driven turbulence where zonal flows are suppressed (Plunk et al., Phys. Rev. Lett., vol. 118, 2017, 105002).

scholarly journals Short wavelength ion temperature gradient turbulence

2012 ◽  
Vol 19 (10) ◽  
pp. 102508 ◽  
Author(s):  
J. Chowdhury ◽  
S. Brunner ◽  
R. Ganesh ◽  
X. Lapillonne ◽  
L. Villard ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Short Wavelength ◽  
Ion Temperature ◽  
Ion Temperature Gradient
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