Nonlinear excitation of finite-radial-scale zonal structures by toroidal Alfvén eigenmode

  title={Nonlinear excitation of finite-radial-scale zonal structures by toroidal Alfv{\'e}n eigenmode},
  author={Zhiyong Qiu and Liu Chen and Fulvio Zonca},
  journal={Nuclear Fusion},
The set of equations describing nonlinear evolution of a single toroidal Alfvén eigenmode are derived, including both zero frequency zonal structure (ZFZS) generation and wave-particle phase space nonlinearities. The simplified case of neglecting wave-particle phase space nonlinearity is then investigated to focus on different roles of energetic particles and bulk plasmas on ZFZS generation. It is shown that energetic particles and bulk plasma play dominant roles in ZFZS generation in different… 

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Two novel nonlinear mode coupling processes for reversed shear Alfvén eigenmode (RSAE) nonlinear saturation are proposed and investigated. In the first process, the RSAE nonlinearly couples to a

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Nonlinear Decay and Plasma Heating by a Toroidal Alfvén Eigenmode.

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Generation of zonal ow (ZF) by energetic particle (EP) driven toroidal Alfven eigenmode (TAE) is investigated using nonlinear gyrokinetic theory. It is found that, nonlinear resonant EP contri-

Nonlinear excitations of zonal structures by toroidal Alfvén eigenmodes.

This work shows that proper accounting for plasma equilibrium geometry as well as including kinetic thermal ion treatment in the nonlinear simulations of Alfvénic modes are important ingredients for realistic comparisons with experimental measurements, where the existence of zonal fields has been clearly observed.

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Nonlinear saturation of toroidal Alfvén eigenmodes via ion compton scattering.

  • HahmChen
  • Physics
    Physical review letters
  • 1995
It is shown that nonlinear ponderomotive force produced by TAE's interaction drives sound-wave-like density fluctuation with low phase velocity which can resonantly interact with the bulk ion parallel motion.

Nonlinear gyrokinetic equations for low-frequency electromagnetic waves in general plasma equilibria

A nonlinear gyrokinetic formalism for low‐frequency (less than the cyclotron frequency) microscopic electromagnetic perturbations in general magnetic field configurations is developed. The nonlinear

Theory on excitations of drift Alfvén waves by energetic particles. I. Variational formulation

A unified theoretical framework is presented for analyzing various branches of drift Alfven waves and describing their linear and nonlinear behaviors, covering a wide range of spatial and temporal

Analysis of the nonlinear behavior of shear-Alfvén modes in tokamaks based on Hamiltonian mapping techniques

We present a series of numerical simulation experiments set up to illustrate the fundamental physics processes underlying the nonlinear dynamics of Alfvenic modes resonantly excited by energetic

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The confinement of energetic particles (EPs) is crucial in the efficient heating of tokamak plasmas. Plasma instabilities such as Alfvén eigenmodes (AEs) can redistribute the EP population, making