Publications associées à Coronal seismology

Nonlinear interaction of Alfvénic instabilities and turbulence via the modification of the equilibrium profiles

Laurent Villard, Alberto Bottino, Xiao Wang

Nonlinear simulations of Alfvén modes (AMs) driven by energetic particles (EPs) in the presence of turbulence are performed with the gyrokinetic particle-in-cell code ORB5. The AMs carry a heat flux, and consequently they nonlinearly modify the plasma temp ...

Cambridge University Press2023

Predictive modeling of Alfvén eigenmode stability in inductive scenarios in JT-60SA

Javier García Hernández, Matteo Vallar, Antonio José Pereira de Figueiredo

The JT-60SA device offers unique conditions before ITER for the study of the interaction of energetic particles with plasma waves. With similar dimensions to JET, e.g., a major radius but with a slightly more elongated plasma volume, JT-60SA is used as a h ...

Frontiers Media Sa2023

The Alfvenic nature of chromospheric swirls

Aleksi Antoine Bossart, Andrea Francesco Battaglia

Context. Observations show that small-scale vortical plasma motions are ubiquitous in the quiet solar atmosphere. They have received increasing attention in recent years because they are a viable candidate mechanism for the heating of the outer solar atmos ...

EDP SCIENCES S A2021

Modification of the Alfven wave spectrum by pellet injection

Olivier Sauter, Ambrogio Fasoli, Yiming Li, Basil Duval, Jonathan Graves, Duccio Testa, Patrick Blanchard, Henri Weisen, Federico Nespoli, Alessandro Pau, Federico Alberto Alfredo Felici, Hamish William Patten, Samuel Lanthaler, Cristian Sommariva, Soo-Jin Moon, Antoine Pierre Emmanuel Alexis Merle, Ricardo Lima, Haomin Sun, Michele Marin, Richard Pitts, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Yao Zhou, Davide Galassi, Antonio José Pereira de Figueiredo, Emiliano Fable, Francesca Maria Poli, Daniele Brunetti, Anna Teplukhina, Alberto Mariani, Kenji Tanaka, Bernhard Sieglin, Otto Asunta, Gergely Papp, Leonardo Pigatto

Alfven eigenmodes driven by energetic particles are routinely observed in tokamak plasmas. These modes consist of poloidal harmonics of shear Alfven waves coupled by inhomogeneity in the magnetic field. Further coupling is introduced by 3D inhomogeneities ...

2019

MHD spectroscopy of JET plasmas with pellets via Alfven eigenmodes

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Martinus Gijs, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Bruno Emanuel Ferreira De Sousa Correia, Alessandro Pau, Pierre-Thomas Paul Brun, Cristian Sommariva, Henri Weisen, Richard Pitts, Sun Hee Kim, Yann Camenen, Jan Horacek, Javier García Hernández, Marco Wischmeier, Mikhail Maslov, Nicola Vianello, Miguel Fernández Ruiz, Federico Nespoli, Antonio José Pereira de Figueiredo, Liang Yao, Yao Zhou, David Pfefferlé, Dalziel Joseph Wilson, Robin Humphry-Baker, Davide Galassi, José Pedro Rebelo Ferreira Marques, Ana Francisca Leal Silva Soares, Jonathan Marc Philippe Faustin, Daniel Scott Alessi, Arnout Lodewijk M Beckers, Julio Rodriguez, Hamish William Patten, Jonnathan Cesar Hidalgo Acosta, Samuel Lanthaler, , , , , , , ,

Mode excitation by an antenna in global gyrokinetic simulations

Laurent Villard, Stephan Brunner, Emmanuel Lanti, Alberto Bottino, Ben McMillan, Noé Thomas Elie Ohana

In order to get a better understanding of the linear and non-linear plasma interaction of microinstabilities and associated turbulence with different specific modes, an antenna is implemented in the global gyrokinetic code ORB5. It consists in applying an ...

2018

Macroscopic Stability of High Beta MAST plasmas

Wilfred Anthony Cooper, Jonathan Graves

The high-beta capability of the spherical tokamak, coupled with a suite of world-leading diagnostics on MAST, has facilitated significant improvements in the understanding of performance-limiting core instabilities in high performance plasmas. For instance ...

IOP Publishing Ltd2011

Active excitation and damping rate measurement of intermediate-n Toroidal Alfvén Eigenmodes in JET, C-Mod and MAST plasmas

Ambrogio Fasoli, Duccio Testa, Theodoros Panis

The stability properties of Alfvén Eigenmodes (AEs) are investigated directly using external antenna excitation and detection of stable modes in a variety of plasma configurations in different devices. Dedicated methods to measure the AE damping rate separ ...

2010

On the Relationship Between the Signature of Close Electric Field and the Equivalent Corona Current in Lightning Return Stroke Models

Farhad Rachidi-Haeri, Carlo Alberto Nucci

Engineering return stroke models can be categorized either as current generation (traveling current source type) models or current propagation (transmission line type) models. The current generation models are described among other parameters by a corona c ...

Institute of Electrical and Electronics Engineers2008

Quantum chaos? Genericity and nongenericity in the MHD spectrum of nonaxisymmetric toroidal plasmas

Ben McMillan

The eigenmode spectrum is a fundamental starting point for the analysis of plasma stability and the onset of turbulence, but the characterization of the spectrum even for the simplest plasma model, ideal magnetohydrodynamics (MHD), is not fully understood. ...

2007

A full-wave solver of the Maxwell's equations in 3D cold plasmas

Laurent Villard, Wilfred Anthony Cooper, Pavel Popovitch

A new solver for Maxwell's equations in three-dimensional (3D) plasma configurations is presented. The new code LEMan (Low-frequency ElectroMagnetic wave propagation) determines a global solution of the wave equation in a realistic stellarator geometry at ...

2006

Stability and toroidal rotation properties of highly shaped plasmas in the TCV tokamak

Andrea Scarabosio

Magnetohydrodynamic (MHD) instabilities and plasma rotation have various impacts on particle and thermal transport in toroidal plasmas. MHD instabilities degrade the confinement, limit the maximum achievable plasma pressure, and can lead to plasma disrupti ...

EPFL2006

Studies of the 'Quiescent H-mode' regime in ASDEX Upgrade and JET

Richard Pitts

The stationary edge localized mode (ELM)-free 'Quiescent H-mode' (QH-mode) regime, obtained with counter neutral beam injection, is studied in ASDEX Upgrade and Joint European Torus. QH-mode plasmas have high pedestal and core ion temperatures together wit ...

IOP Publishing Ltd2005