Related papers: Zero frequency zonal flow excitation by energetic …
The role of self-generated zonal flows in the collisionless trapped-electron mode (CTEM) turbulence is a long-standing open issue in tokamak plasmas. Here we show, for the first time, that the zonal flow excitation in the CTEM turbulence is…
The goal of magnetic fusion research is to extract the power released by fusion reactions and carried by the product of these reactions, liberated at energies of the order of a few MeV. The feasibility of fusion energy production relies on…
The derivation of an intermediate-scale gyrokinetic-electron theory in nonuniform tokamak plasmas [Chen H. et al 2021 Nucl. Fusion 61 066017] has shown that a Navier-Stokes type nonlinearity couples electron-temperature-gradient (ETG) modes…
In the present work the generation of zonal flows in collisionless trapped electron mode (TEM) turbulence is studied analytically. A reduced model for TEM turbulence is utilized based on an advanced fluid model for reactive drift waves. An…
The generation of large-scale zonal flows by small-scale electrostatic drift waves in electron temperature gradient(ETG) driven turbulence model is considered. The generation mechanism is based on the modulational instability of a finite…
The excitation of toroidicity induced Alfv{\'e}n eigenmodes (TAEs) using prescribed external electromagnetic perturbations (hereafter ``antenna") acting on a confined toroidal plasma as well as its nonlinear couplings to other modes in the…
In this letter, it is reported that the first experimental results are associated with the GAM induced by energetic electrons (eEGAM) in HL-2A Ohmic plasma. The energetic-electrons are generated by parallel electric fields during magnetic…
Compressional Alfv\'en eigenmodes (CAE) driven by energetic ions have been observed in magnetic fusion experiments. In this paper, we show that the modes can also be driven by runaway electrons formed in post-disruption plasma, which may…
Nonlinear generation of high frequency mode (HFM) by toroidal Alfven eigenmode (TAE) observed in HL-2A tokamak is analyzed using nonlinear gyrokinetic theory. It is found that, the HFM can be dominated by $|nq-m|=1$ perturbations with…
The resonant and non-resonant effects of core plasma on the excitation of low frequency modes with $\omega < \omega_{BAE}$, such as Beta-induced Alfv\'en Acoustic Eigenmodes (BAAEs) and Kinetic Ballooning Modes (KBMs) are examined in the…
The indirect nonlinear interactions between toroidal Alfv\'en eigenmode (TAE) and ion temperature gradient mode (ITG) are investigated using nonlinear gyrokinetic theory and ballooning mode formalism. More specifically, the local nonlinear…
It is shown that force-free electrodynamics (FFE) breaks down in regions where $B^2 -E^2 <0$ (electric zones) even if $\pmb{E}\cdot\pmb{B} =0$. Spontaneous creation of such regions will inevitably lead to plasma oscillations that will…
Novel mechanisms for zonal flow (ZF) generation for both large relative density fluctuations and background density gradients are presented. In this non-Oberbeck-Boussinesq (NOB) regime ZFs are driven by the Favre stress, the large…
The confinement of energetic particles (EP) is crucial for an efficient heating of tokamak plasmas. Plasma instabilities such as Alfven Eigenmodes (AE) can redistribute the EP population making the plasma heating less effective, and leading…
In nonlinear systems, small perturbations are conventionally attributed to negligible nonlinearity, justifying linear approximations. Here, we uncover a notable exception to this paradigm in an electrokinetic (EK) flow. Using a novel dual…
Using electron drift wave (eDW) as a paradigm model, we have investigated analytically direct wave-wave interactions between a test DW and ambient toroidal Alfv\'en eigenmodes (TAE) in toroidal plasmas, and their effects on the stability of…
The linear properties of the low-frequency shear Alfv\'en waves such as those associated with the beta-induced Alfv\'en eigenmodes (BAEs) and the low-frequency modes observed in reversed-magnetic-shear DIII-D discharges (W. Heidbrink, et al…
We present a procedure to examine energetic particle phase-space during long range frequency chirping phenomena in tokamak plasmas. To apply the proposed method, we have performed self-consistent simulations using the MEGA code and analyzed…
Fully self-consistent hybrid MHD/particle simulations reveal strong energetic particle modifications to sub-cyclotron global Alfv\'{e}n eigenmodes (GAE) in low-aspect ratio, NSTX-like conditions. Key parameters defining the fast ion…
Alfven Eigenmodes (AE) can be destabilized by energetic particles in neutral beam injection (NBI) heated plasmas through inverse Landau damping and couplings with gap modes in the shear Alfven continua. We describe the linear evolution of…