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Concept

Coronal seismology

Publications associées (13)

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

Laurent Villard, Alberto Bottino

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, Antonio José Pereira de Figueiredo, Matteo Vallar

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

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

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

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 ...

IOP Publishing Ltd2019

MHD spectroscopy of JET plasmas with pellets via Alfven eigenmodes

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

Alfven eigenmodes (AEs) are routinely seen in present-day tokamaks and stellarators with energetic particles and they represent an attractive form of MHD spectroscopy that provides valuable information on background plasma and on the energetic particles. P ...

IOP Publishing Ltd2018

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

Jonathan Graves, Wilfred Anthony Cooper

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