A5002398922- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Tropical and Extratropical Cyclones Research
University of Science and Technology of China
2023-2024
Abstract We analytically investigate geodesic acoustic modes (GAMs) in tokamak plasmas with up-down asymmetric and non-circular cross-sections using magnetohydrodynamics (MHD) a Miller-like flux surface model. Explicit expressions for GAM frequency, magnetic field perturbations, Lagrangian displacement are presented. Our results reveal that (I) asymmetry (σ) slightly increases the frequency introduces additional sin or cos components (opposite to dominant component) perturbations; (II)...
Abstract Electromagnetic geodesic acoustic modes (GAMs) are analytically investigated in tokamak plasmas with anisotropy, utilizing gyro-kinetic equations and a rigorously self-consistent anisotropic distribution. When including first-order finite-orbit-width effects finite-Larmor-radius effects, it is proven that the anisotropy an arbitrary strength does not induce m=±1 harmonics of A ∥ , where m denote poloidal wavenumber parallel component perturbed magnetic vector potential,...
Abstract Plasma elongation effects on energetic particle-induced geodesic acoustic modes (EGAMs) are theoretically investigated by using gyro-kinetic equations and the Miller local equilibrium model. Including an arbitrary κ a finite radial derivative <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>s</mml:mi> <mml:mi>κ</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mi>r</mml:mi> <mml:mi mathvariant="normal">∂</mml:mi> <mml:mrow> <mml:mo>/</mml:mo>...
Abstract The geodesic acoustic mode (GAM) is investigated with gyro-kinetic equations in Miller local equilibrium model for shaped tokamak plasmas an arbitrary elongation κ and a finite triangularity δ . In particular, the effects of on GAM frequency damping rate are analyzed both analytically numerically. asymptotic analytical exact numerical results show that almost linearly increases but relatively more slowly negative , which agree well TCV observation trend. clearly claim effect...
Abstract This study presents an analytical investigation of energetic particle-induced geodesic acoustic modes (EGAMs) within a gyro-kinetic model, incorporating finite-orbit-width (FOW) effects up to the second order. The inclusion second-order FOW introduces two distinct types particle-wave resonances, occurring at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>ω</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mi>t</mml:mi> <mml:mi>h</mml:mi>...
Velocity, density, and magnetic fluctuations of the geodesic acoustic mode (GAM) have been measured using Doppler backscattering system, Faraday-effect polarimeter-interferometer, external pick-up coils in Experimental Advanced Superconducting Tokamak. Simultaneous measurements density velocity at midplane top plasmas demonstrate that m = 1 are quantitatively balanced by compression perpendicular flow fluctuations. Furthermore, internal associated with GAM now directly laser-based...