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Related papers: On How Zonal Fields Suppress Reversed Shear Alfv\'…

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General nonlinear equations describing reversed shear Alfven eigenmode (RSAE) self-modulation via zero frequency zonal structure (ZFZS) generation are derived using nonlinear gyrokinetic theory, which are then applied to study the…

Plasma Physics · Physics 2021-10-04 Shizhao Wei , Tao Wang , Ningfei Chen , Zhiyong Qiu

Following the analysis on linear spectra of shear Alfv\'en fluctuations excited by energetic particles (EPs) in the Divertor Tokamak Test (DTT) facility plasmas [T. Wang et al., Phys. Plasmas 25, 062509 (2018)], in this work, nonlinear…

Plasma Physics · Physics 2019-01-30 Tao Wang , Xin Wang , Sergio Briguglio , Zhiyong Qiu , Gregorio Vlad , Fulvio Zonca

A novel channel for fuel ions heating in tokamak core plasma is proposed and analyzed using nonlinear gyrokinetic theory. The channel is achieved via spontaneous decay of reversed shear Alfv\'en eigenmode (RSAE) into low frequency Alfv\'en…

Plasma Physics · Physics 2023-07-11 Zhiyong Qiu , Shizhao Wei , Tao Wang , Liu Chen , Fulvio Zonca

A novel channel for fuel ions heating in tokamak core plasma is proposed and analyzed using nonlinear gyrokinetic theory. The channel is achieved via spontaneous decay of reversed shear Alfven eigenmode (RSAE) into low frequency Alfven…

Plasma Physics · Physics 2022-04-14 Shizhao Wei , Tao Wang , Liu Chen , Fulvio Zonca , Zhiyong Qiu

Chirping Alfv\'{e}n modes are considered as potentially harmful in burning Tokamak plasmas. In this paper, the nonlinear evolution of a single-toroidal-number chirping mode is analysed by numerical particle simulation. This analysis can be…

Hybrid MHD-gyrokinetic code simulations are used to investigate the dynamics of frequency sweeping reversed shear Alfv\'en eigenmode (RSAE) strongly driven by energetic particles (EPs) during plasma current ramp-up in a conventional tokamak…

Plasma Physics · Physics 2020-08-28 Tao Wang , Zhiyong Qiu , Fulvio Zonca , Sergio Briguglio , Gregorio Vlad

The linear destabilization and nonlinear saturation of energetic-particle driven Alfv\'enic instabilities in tokamaks strongly depend on the damping channels. In this work, the collisionless damping mechanisms of Alfv\'enic modes are…

A general methodology is proposed to differentiate the likelihood of energetic-particle-driven instabilities to produce frequency chirping or fixed-frequency oscillations. The method employs numerically calculated eigenstructures and…

We demonstrate analytically that, in toroidal plasmas, scattering by drift wave turbulence could lead to appreciable damping of toroidal Alfven eigenmodes via generation of short-wavelength electron Landau damped kinetic Alfven waves. A…

Plasma Physics · Physics 2022-07-20 Liu Chen , Zhiyong Qiu , Fulvio Zonca

A nonlinear saturation mechanism for reversed shear Alfven eigenmode (RSAE) is proposed and analysed, and is shown to be of relevance to typical reactor parameter region. The saturation is achieved through the generation of high-frequency…

Plasma Physics · Physics 2024-06-11 Zhiwen Cheng , Guangyu Wei , Lei Ye , Zhiyong Qiu

The nonlinear saturation of toroidal Alfven eigenmode (TAE) due to thermal plasma nonlinearities is investigated using gyrokinetic particle-in-cell simulations and theoretical analysis. In the single toroidal mode number simulations with…

A new analytic expression is derived for the resonant drive of high n Alfvenic modes by particles accelerated to high energy by Ion Cyclotron Resonance Heating. This derivation includes finite orbit effects, and the formalism is completely…

Plasma Physics · Physics 2009-11-05 I. G. Abel , B. N. Breizman , S. E. Sharapov , JET-EFDA Contributors

A novel 2D nonlinear dynamical paradigm is constructed to interpret the fast and repetitive frequency chirping and amplitude oscillation of Alfv\'en eigenmodes excited by energetic particles in fusion plasmas as observed in global…

Plasma Physics · Physics 2021-12-01 Junyi Cheng , Wenlu Zhang , Zhihong Lin , Jian Bao , Chao Dong , Jintao Cao , Ding Li

We report the first experimental detection of a zero-frequency fluctuation that is pumped by an Alfv\`en mode in a magnetically confined plasma. Core-localized bidirectional Alfv\`en modes of frequency inside the toroidicity-induced gap…

Strongly driven ion-scale turbulence in tokamak plasmas is shown to be regulated by a new propagating zonal flow mode, the toroidal secondary mode, which is nonlinearly supported by the turbulence. The mode grows and propagates due to the…

Plasma Physics · Physics 2026-03-24 Richard Nies , Felix Parra , Michael Barnes , Noah Mandell , William Dorland

The linear dynamics of Alfven modes in tokamaks is investigated here by means of the global gyrokinetic particle-in-cell code NEMORB. The model equations are shown and the local shear Alfven wave dispersion relation is derived, recovering…

Plasma Physics · Physics 2016-02-17 A. Biancalani , A. Bottino , S. Briguglio , A. Koenies , Ph. Lauber , A. Mishchenko , E. Poli , B. D. Scott , F. Zonca

Currents driven by rf (radio frequency) waves in the interior of magnetic islands can stabilize deleterious tearing modes in tokamaks. Present analyses of stabilization assume that the local electron acceleration is unaffected by the…

Plasma Physics · Physics 2018-12-05 A. H. Reiman , N. J. Fisch

The Earth's magnetosheath provides a high $\beta$ (ratio of electron thermal pressure to magnetic pressure) plasma environment where kinetic Alfv\'en waves (KAWs) strongly influence turbulence and energy dissipation. This study investigates…

Plasma Physics · Physics 2025-12-11 Mani K. Chettri , Hemam D. Singh , Vivek Shrivastav , Britan Singh , Rupak Mukherjee

In this work, we use the global electromagnetic and electrostatic gyro kinetic approaches to investigate the effects of zonal flows forced-driven by Alfv\'en modes due to their excitation by energetic particles (EPs), on the dynamics of ITG…

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- bution dominates over the usual Reynolds and…

Plasma Physics · Physics 2016-10-12 Zhiyong Qiu , Liu Chen , Fulvio Zonca
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