scholarly journals Modelling of drift wave turbulence with a finite ion temperature gradient

1990 ◽  
Author(s):  
S. Hamaguchi ◽  
W. Horton
Keyword(s):  
Temperature Gradient ◽  
Wave Turbulence ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Drift Wave Turbulence ◽  
Drift Wave

scholarly journals Investigation of tokamak turbulent avalanches using wave-kinetic formulation in toroidal geometry

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Camille Gillot ◽  
Guilhem Dif-Pradalier ◽  
Xavier Garbet ◽  
Olivier Panico ◽  
Yanick Sarazin ◽  
...  
Keyword(s):  
Coupled System ◽  
Wave Turbulence ◽  
Ion Temperature ◽  
Flow Shear ◽  
Ion Temperature Gradient ◽  
Kinetic Formulation ◽  
Drift Wave Turbulence ◽  
Drift Wave ◽  
Low Field ◽  
Primary Driver

The interplay between toroidal drift-wave turbulence and tokamak profiles is investigated using a wave-kinetic description. The coupled system is used to investigate the interplay between marginally stable toroidal drift-wave turbulence and geodesic acoustic modes (GAMs). The coupled system is found to be unstable. Notably, the most unstable mode corresponds to the resonance between the turbulent wave radial group velocity and the GAM phase velocity. For a low-field-side ballooned drift-wave growth, a background flow shear breaks the symmetry between inwards- and outwards-travelling instabilities. Although this turbulence–GAM coupling may not be the primary driver for avalanches in standard core ion temperature gradient simulations, this mechanism is generic and displays many of the expected features, and should be of interest in several other regimes, which include towards the edge or in the presence of energetic particles.

Excitation of geodesic acoustic mode continuum by drift wave turbulence

2012 ◽  
Vol 78 (6) ◽  
pp. 651-655 ◽  
Author(s):  
JUN YU ◽  
J. Q. DONG ◽  
X. X. LI ◽  
D. DU ◽  
X. Y. GONG
Keyword(s):  
Growth Rate ◽  
Acoustic Mode ◽  
Kinetic Approach ◽  
Wave Turbulence ◽  
Ion Temperature ◽  
Drift Wave Turbulence ◽  
Acoustic Modes ◽  
Drift Wave ◽  
Radial Structure ◽  
Geodesic Acoustic Mode

AbstractExcitation of the geodesic acoustic mode continuum by drift wave turbulence is studied using the wave kinetic approach. For a model profile of weak non-uniform ion temperature, the forms of growth rate and radial structure of geodesic acoustic modes are obtained analytically. The growth rate is analyzed for several conditions for present-day tokamaks and compared with that for uniform ion temperature, as well as that given by the coherent mode approach for non-uniform ion temperature.

Turbulent impurity transport modeling for Alcator C-Mod

2013 ◽  
Vol 79 (5) ◽  
pp. 837-846 ◽  
Author(s):  
X. R. FU ◽  
W. HORTON ◽  
I. O. BESPAMYATNOV ◽  
W. L. ROWAN ◽  
S. BENKADDA ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Particle Transport ◽  
Eigenvalue Problems ◽  
Ion Temperature ◽  
Transport Barrier ◽  
Quasilinear Theory ◽  
Ion Temperature Gradient ◽  
Drift Wave ◽  
Impurity Density ◽  
Impurity Transport

AbstractTurbulent particle transport is investigated with a quasilinear theory that is motivated by the boron impurity transport experiments in the Alcator C-Mod. Eigenvalue problems for sets of reduced fluid equations for multi-component plasmas are solved for the self-consistent fluctuating field vectors composed of the electric potential φ, the main ion density δni, the impurity density δnz and the ion temperature fluctuation δTi. For Alcator C-Mod parameters, we investigate two drift wave models: (1) the density-gradient-driven impurity drift wave and (2) the ion-temperature-gradient-driven ion temperature gradient (ITG) mode. Analytic and numerical results for particle transport coefficients are derived and compared with the transport data and the neoclassical theory. We explore the ability of the model to explain impurity density profiles in three confinement regimes: H-mode, I-mode and internal transport barrier (ITB) regime in C-Mod. Related experiments reported on the Large Helical Device are briefly discussed.

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