Publications associées à Bohm diffusion

Nonlinear simulation of plasma turbulence using a gyrokinetic moment-based approach

Plasma turbulence plays a fundamental role in determining the performances of magnetic confinement fusion devices, such as tokamaks. Advances in computer science, combined with the development of efficient physical models, have significantly improved our u ...

EPFL2024

Simulating Microswimmers Under Confinement With Dissipative Particle (Hydro) Dynamics

Ignacio Pagonabarraga Mora

In this work we study microwimmers, whether colloids or polymers, embedded in bulk or in confinement. We explicitly consider hydrodynamic interactions and simulate the swimmers via an implementation inspired by the squirmer model. Concerning the surroundin ...

FRONTIERS MEDIA SA2022

Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X

Jieping Zhu, Nicola Vianello, Jonathan Marc Philippe Faustin, Eduardo Sanchez, Jonathan Graves, Alberto Bottino, Emiliano Fable, Joaquim Loizu Cisquella, Frank Rüdiger Wagner, Thomas Binderup Jensen, Attila Bencze, Gregory Vogel, Antoine Baillod, Mike Machielsen

We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been ...

IOP Publishing Ltd2022

Interpretation of electromagnetic modes in the sub-TAE frequency range in JET plasmas with elevated monotonic q-profiles

Paulo Giovane Paschoali Pereira Puglia

Recent JET deuterium experiments with an advanced tokamak scenario using an internal transport barrier (ITB) have been performed to clearly observe destabilized toroidicity-induced Alfven eigenmodes (TAEs) by fast ions; interestingly, these also exhibit un ...

2021

A fast-moving Langmuir probe array for the divertor of the Tokamak à Configuration Variable

Hugo De Oliveira

In next step tokamaks such as ITER and future fusion power plants, wall materials will be subjected to considerably higher heat and particle fluxes than in present-day machines. Maintaining plasma facing components in good condition and simultaneously assu ...

EPFL2021

Development of free-boundary equilibrium and transport solvers for simulation and real-time interpretation of tokamak experiments

Francesco Carpanese

To exploit fusion as a source of energy, a hot and dense confined plasma is needed. This is achieved in tokamaks by actively controlling the plasma state meaning shape, position and internal kinetic profiles. This thesis addresses two topics: the developme ...

EPFL2021

RF plasma simulations using the TOMATOR 1D code: a case study for TCV helium ECRH plasmas

Stefano Coda

The 1-dimensional reaction-diffusion-convection code TOMATOR-1D describes plasma production by RF waves inside a tokamak using the Braginskii continuity and heat balance equations. The model simulates self-consistent radial density and temperature profiles ...

2020

Effect of periodic gas-puffs on drift-tearing modes in ADITYA/ADITYA-U tokamak discharges

Harshita Raj

The effect of a periodic train of short gas-puff pulses on the rotation frequency and amplitude of drift-tearing modes has been studied in ADITYA/ADITYA-U tokamak. The short gas puffs, injecting approximately similar to 10(17)-10(18) molecules of fuel gas ...

IOP Publishing Ltd2020

Validation of the BEAMS3D neutral beam deposition model on Wendelstein 7-X

Jonathan Graves, David Pfefferlé, Mike Machielsen

The neutral beam deposition model in the BEAMS3D code is validated against neutral beam attenuation data from Wendelstein 7-X (W7-X). A set of experimental discharges where the neutral beam injection system of W7-X was utilized were reconstructed. These di ...

IOP Publishing Ltd2020

Characterizing time intermittency in non-diffusive fast ion transport through plasma turbulence

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Marcelo Baquero Ruiz, Oulfa Chellaï, Fabian Manke

Turbulent fast ion transport has been investigated in astrophisycal, laboratory and fusion plasmas. When gyro- and drift-averaging across plasma structures manifest as non-markovian and non-local effects, this results in generally non-diffusive transport. ...

IOP PUBLISHING LTD2020

Fast ion transport phenomena in turbulent toroidal plasmas

Fabian Manke

In the field of plasma physics, suprathermal ions are encountered e.g. in astrophysical jets, the solar wind, as well as fusion plasmas, where they originate from neutral beam injection or fusion reactions. One aspect of shared interest with astrophysical ...

EPFL2020

Identification of an Optimized Heating and Fast Ion Generation Scheme for the Wendelstein 7-X Stellarator

Wilfred Anthony Cooper, David Pfefferlé, Jonathan Graves, Hamish William Patten

A Doppler shifted resonance minority species ion cyclotron range of frequency (ICRF) scheme for heating neutral beam ions has been identified and optimized for theWendelstein 7-X stellarator. Compared with more conventional methods, the synergetic scheme i ...

2020

EDGE2D-EIRENE simulations of the influence of isotope effects and anomalous transport coefficients on near scrape-off layer radial electric field

Olivier Sauter, Basil Duval, Henri Weisen, Martinus Adela Maria Gijs, Jonathan Graves, Ambrogio Fasoli, Stefano Coda, Patrick Blanchard, Richard Pitts, Yves Martin, Yann Camenen, Javier García Hernández, Duccio Testa, Marco Wischmeier, Miguel Fernández Ruiz, Nicola Vianello, Sun Hee Kim, Federico Nespoli, Alessandro Pau, David Pfefferlé, Davide Galassi, Jonathan Marc Philippe Faustin, Dalziel Joseph Wilson, Cristian Sommariva, Hamish William Patten, Samuel Lanthaler, Jan Horacek, José Pedro Rebelo Ferreira Marques, Mikhail Maslov, Liang Yao, Daniel Scott Alessi, Jonnathan Cesar Hidalgo Acosta, Antonio José Pereira de Figueiredo, Alberto Hernando de Castro, Julio Rodriguez, Li Shuai, Rebecca Hill

EDGE2D-EIRENE (the 'code') simulations show that radial electric field, Er, in the near scrape-off layer (SOL) of tokamaks can have large variations leading to a strong local E x B shear greatly exceeding that in the core region. This was pointed out in si ...

2019

Direct gyrokinetic comparison of pedestal transport in JET with carbon and ITER-like walls

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

This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). Th ...

IOP Publishing Ltd2019

Role of fast ion pressure in the isotope effect in JET L-mode plasmas

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, Alberto Mariani, Michele Marin

This paper presents results of JET ITER-like wall L-mode experiments in hydrogen and deuterium (D) plasmas, dedicated to the study of the isotope dependence of ion heat transport by determination of the ion critical gradient and stiffness by varying the io ...

IOP Publishing Ltd2019

Convection‐Diffusion Competition Within Mixed Layers of Stratified Natural Waters

Alfred Johny Wüest, Damien Bouffard, Oscar Rodrigo Sepúlveda Steiner

In stratified natural waters, convective processes tend to form nearly homogeneous mixed layers. However, shear‐driven turbulence generated by large‐scale background flow often rapidly smooths them through mixing with the stratified surroundings. Here we s ...

2019

Radial variation of heat transport in L-mode JET discharges

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

In this paper, we analyze heat transport in the JET tokamak using data from its high resolution ECE diagnostic and analyses based on the transfer entropy (TE). The analysis reveals that heat transport is not smooth and continuous, but is characterized by ' ...

IOP Publishing Ltd2019

Heat flux analysis of Type-I ELM impact on a sloped, protruding surface in the JET bulk tungsten divertor

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

Tungsten (W) melting due to transient power loads, for example those delivered by edge localised modes (ELMs), is a major concern for next step fusion devices. A series of experiments has been performed on JET to investigate the dynamics of Type-I ELM-indu ...

Elsevier2018

Analysis of ELM stability with extended MHD models in JET, JT-60U and future JT-60SA tokamak plasmas

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

The stability with respect to a peeling-ballooning mode (PBM) was investigated numerically with extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI code was used to analyze the linear stability, including the effects of ...

IOP PUBLISHING LTD2018

The effect of the secondary x-point on the scrape-off layer transport in the TCV snowflake minus divertor

Basil Duval, Benoît Labit, Holger Reimerdes, Christian Gabriel Theiler, Cedric Kar-Wai Tsui, Umar Sheikh, Roberto Maurizio

The snowflake (SF) magnetic configuration is investigated as a potential power exhaust solution for a fusion reactor, but also to improve our understanding of divertor physics in general. Unlike a conventional single null (SN), it features an additional ne ...

IOP Publishing Ltd2018