Gyrokinetic theory of the nonlinear saturation of toroidal Alfven eigenmode

TL;DR

This paper investigates how ion-induced scatterings lead to the nonlinear saturation of toroidal Alfven eigenmodes in gyrokinetic regimes, highlighting the dependence on plasma beta and deriving related saturation levels and transport coefficients.

Contribution

It introduces a gyrokinetic theory for the nonlinear saturation of TAE, emphasizing the role of ion scatterings and plasma beta in the process.

Findings

Saturation levels depend on plasma beta value.

Derived energetic-particle transport coefficients.

Nonlinear evolution varies with ion thermal pressure ratio.

Abstract

Nonlinear saturation of toroidal Alfven eigenmode (TAE) via ion induced scatterings is investigated in the short-wavelength gyrokinetic regime. It is found that the nonlinear evolution depends on the thermal ion \b{eta} value. Here, \b{eta} is the plasma thermal to magnetic pressure ratio. Both the saturation levels and associated energetic-particle transport coefficients are derived and estimated correspondingly.