Publications related to Kink instability

Characterization of Transverse Instabilities Driven by Electron Cloud

Electron cloud continues to be one of the main limiting factors of the Large Hadron Collider (LHC), the biggest accelerator at CERN. These clouds form in the beam chamber when positively charged particles are passing through and cause unwanted effects in b ...

EPFL2024

Numerical studies on saturated kink and sawtooth induced fast ion transport in JET ITER-like plasmas

Mario Ludovico Podesta, Matteo Vallar

This presentation examines the energetic particle transport induced by saturated kink modes and sawtooth crashes in JET deuterium plasmas. It is known that kink mode-resonant transport and phase-space redistribution from sawtooth crashes can drive strong f ...

IOP Publishing Ltd2022

Excitation of Alfven eigenmodes by fusion-born alpha-particles in D-He-3 plasmas on JET

Henri Weisen, Javier García Hernández

Alfven eigenmode (AE) instabilities driven by alpha-particles have been observed in D-He-3 fusion experiments on the Joint European Torus (JET) with the ITER-like wall. For the efficient generation of fusion alpha-particles from D-He-3 fusion reaction, the ...

2022

A Fast Ion Loss Detector for the TCV Tokamak

Lorenzo Stipani

A Fast Ion Loss Detector (FILD) was designed, assembled, installed and commissioned for TCV. This is a radially positionable, scintillator based detector that provides information on the 2D fast-ion velocity space lost at the probe's location. The collecte ...

EPFL2021

Studying the effect of non-adiabatic passing electron dynamics on microturbulence self-interaction in fusion plasmas using gyrokinetic simulations

Ajay Chandrarajan Jayalekshmi

Microturbulence driven by plasma instabilities is in most cases the dominant cause of heat and particle loss from the core of magnetic confinement fusion devices and therefore presents a major challenge in achieving burning plasma conditions. The role of p ...

EPFL2020

Negative ion characterization in a helicon plasma source for fusion neutral beams by cavity ring-down spectroscopy and Langmuir probe laser photodetachment

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello, Gennady Plyushchev

Negative ions are characterized in the helicon plasma source resonant antenna ion device (RAID) at the Swiss plasma center by means of cavity ring-down spectroscopy (CRDS) and Langmuir probe (LP)-assisted laser photodetachment. A high density and axially h ...

IOP Publishing Ltd2020

Progress in disruption prevention for ITER

Olivier Sauter, Mengdi Kong, Alessandro Pau, Francesca Maria Poli, Umar Sheikh, Ji Hyun Kim

Key plasma physics and real-time control elements needed for robustly stable operation of high fusion power discharges in ITER have been demonstrated in recent research worldwide. Recent analysis has identified the current density profile as the main drive ...

IOP Publishing Ltd2019

Simulation of neutron emission in neutral beam injection heated plasmas with the real-time code RABBIT

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Henri Weisen, Alessandro Pau, Federico Nespoli, Cristian Sommariva, David Pfefferlé, Richard Pitts, Jonathan Marc Philippe Faustin, Yann Camenen, Hamish William Patten, Jan Horacek, Samuel Lanthaler, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov, Yao Zhou, Davide Galassi, Antonio José Pereira de Figueiredo, Liang Yao, Dalziel Joseph Wilson, Bernhard Sieglin, Otto Asunta

In plasmas heated with deuterium beams a deficit of the expected fusion neutron rate is an indicator of the deterioration of the fast-ion confinement, caused, for instance, by magnetohydrodynamic instabilities. The capability of predicting this deficit dur ...

IOP Publishing Ltd2019

Advanced linear models for gyro-backward wave instabilities in gyrotrons

Jérémy Genoud

Parasitic oscillations excitation is one of the main point hindering high-power gyrotron operation for fusion application. These instabilities, besides being dangerous for the gyrotron components, could possibly degrade the electron beam quality before it ...

EPFL2019

A Variable Structure Control Scheme Proposal for the Tokamak a Configuration Variable

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Ivo Furno, Duccio Testa, Minh Quang Tran, Paolo Ricci, Patrick Blanchard, Holger Reimerdes, Benoît Labit, Jean-Philippe Hogge, Christian Gabriel Theiler, Laurie Porte, Alessandro Pau, Alexander Karpushov, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Joan Decker, Xavier Llobet, Umar Sheikh, Cristian Galperti, Christian Schlatter, Yanis Andrebe, Rémy Jacquier, Mengdi Kong, Oulfa Chellaï, Falk Hans Braunmüller, Francesco Carpanese, Henri Weisen, Federico Nespoli, Yann Camenen, Fabio Riva, Jan Horacek, Anna Teplukhina, Marco Wischmeier, Roberto Maurizio, , , , , , , , , , , , , ,

Analysis of runaway electron expulsion during tokamak instabilities detected by a single-channel Cherenkov probe in FTU

Cristian Galperti, Gabriele Grosso, Filippo Bagnato

The expulsion of runaway electrons (REs) during different types of tokamak instabilities is analysed by means of a Cherenkov probe inserted into the scrape-off layer of the FTU tokamak. One such type of instability, the well-known tearing mode, is involved ...

IOP Publishing Ltd2019

A novel approach to Landau damping of transverse collective instabilities in future hadron colliders

Michael Schenk

Transverse collective instabilities induced by the beam-coupling impedance of the accelerator structure lead to beam quality degradation and pose a major limitation to the machine performance. Landau damping, a powerful stabilising mechanism that can be em ...

EPFL2019

Absolute/convective secondary instabilities and the role of confinement in free shear layers

François Gallaire, Cristobal Manuel Arratia Martinez, Saviz Mowlavi

We study the linear spatiotemporal stability of an infinite row of equal point vortices under symmetric confinement between parallel walls. These rows of vortices serve to model the secondary instability leading to the merging of consecutive (Kelvin-Helmho ...

2018

Turbulence studies in TCV using the Correlation ECE diagnostic

Matteo Fontana

In this thesis work, the flexibility of the Tokamak à Configuration Variable (TCV) is exploited to study the influence of plasma parameters on turbulent fluctuations. The correlation electron cyclotron emission (CECE) diagnostic is used to measure low ampl ...

EPFL2018

Sliding Surface Based Schemes for the Tokamak a Configuration Variable

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Stefano Alberti, Ivo Furno, Duccio Testa, Minh Quang Tran, Paolo Ricci, Patrick Blanchard, Holger Reimerdes, Benoît Labit, Jean-Philippe Hogge, Christian Gabriel Theiler, Laurie Porte, Alessandro Pau, Alexander Karpushov, Federico Alberto Alfredo Felici, Bernard Schneider, Antoine Pierre Emmanuel Alexis Merle, Joan Decker, Xavier Llobet, Umar Sheikh, Cristian Galperti, Christian Schlatter, Yanis Andrebe, Rémy Jacquier, Mengdi Kong, Oulfa Chellaï, Falk Hans Braunmüller, Francesco Carpanese, Pedro Andres Molina Cabrera, Yann Camenen, Miguel Filipe Silva Füglister, Henri Weisen, Jan Horacek, Marco Wischmeier, , , , , , , , , , , , , , , , , , ,

Observation of short time-scale spectral emissions at millimeter wavelengths with the new CTS diagnostic on the FTU tokamak

Cristian Galperti, Gabriele Grosso

On the FTU tokamak, the collective Thomson scattering (CTS) diagnostic was renewed for investigating the possible excitation of parametric decay instabilities (PDI) by electron cyclotron (EC) or CTS probe beams in presence of magnetic islands and measure t ...

IOP Publishing Ltd2017

Self-consistent interaction of fast particles and ICRF waves in 3D applications of fusion plasma devices

Jonathan Marc Philippe Faustin

Tokamaks and stellarators are the most promising reactor concepts using the magnetic confinement to contain the plasma fuel. Reactors capable of sustaining deuterium-tritium (D-T) fusion reactions requires the confinement of a very high temperature plasma ...

EPFL2017

Upgrades of Diagnostic Techniques and Technologies for JET Next D-T Campaigns

Patrick Blanchard

In the perspective of reducing ITER risks, JET next DT campaign presents a unique potential, since the device can combine the right first wall material mix, the reactor fuel mixture and sufficient dimensions and fields to confine the alpha particles. An in ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Spatio-temporal stability of the Kármán vortex street and the effect of confinement

François Gallaire, Cristobal Manuel Arratia Martinez, Saviz Mowlavi

The instability of the Kármán vortex street is revisited under a spatio-temporal perspective that allows the taking into account of the advection of the vortices by the external flow. We analyse a simplified point vortex model and show through numerical si ...

Cambridge University Press2016

Free boundary equilibrium in 3D tokamaks with toroidal rotation

Olivier Sauter, Jonathan Graves, Wilfred Anthony Cooper, Minh Tâm Tran, David Pfefferlé, Jonathan Marc Philippe Faustin, Daniele Brunetti, Madhusudan Raghunathan

The three-dimensional VMEC equilibrium solver has been adapted to numerically investigate the approximate toroidal rotation model we have derived. We concentrate our applications on the simulation of JET snakes and MAST long-lived modes under free boundary ...

IOP Publishing Ltd2015