Publications associées à Plasma confinement

Towards practical reinforcement learning for tokamak magnetic control

Federico Alberto Alfredo Felici, Cristian Galperti, Jonas Buchli, Brendan Tracey

Reinforcement learning (RL) has shown promising results for real-time control systems, including the domain of plasma magnetic control. However, there are still significant drawbacks compared to traditional feedback control approaches for magnetic confinem ...

Elsevier Science Sa2024

Re-design of EU DEMO with a low aspect ratio

Hartmut Zohm

The design point that had been chosen for EU DEMO in 2016 is reviewed here and a modification is proposed with a lower aspect ratio. Previously the same aspect ratio, A, was chosen for EU DEMO as in major tokamak experiments including ITER (A = 3.1), and, ...

2024

Experimental study and interpretative modelling of the Power Exhaust in Configurations with Multiple X-Points in TCV

Sophie Danielle Angelica Gorno

Nuclear fusion presents a promising clean energy source to mitigate future energy crises, with magnetic confinement fusion well-positioned to provide a baseload scenario to power future reactors. The unmitigated power exhaust of such reactors threatens its ...

EPFL2024

Integrated modelling of neon impact on JET H-mode core plasmas

Yann Camenen, Michele Marin

Nuclear fusion reactor plasmas will need to exhaust a significant proportion of energy flux through radiative processes, to enable acceptable divertor loads. This can be obtained by line radiation from impurities, injected from the plasma edge. There are h ...

IOP Publishing Ltd2023

A machine-learning-based tool for last closed-flux surface reconstruction on tokamaks

Olivier Sauter, Alessandro Pau, Xiaojuan Liu, Chenguang Wan

Tokamaks allow to confine fusion plasma with magnetic fields. The prediction/reconstruction of the last closed-flux surface (LCFS) is one of the primary challenges in the control of the magnetic configuration. The evolution in time of the LCFS is determine ...

IOP Publishing Ltd2023

3D Characterisation of Turbulent Plasma Filaments Using Gas Puff Imaging in the Tokamak à Configuration Variable

Nicola Offeddu

A key challenge for the development of fusion reactors based on magnetic confinement, such as tokamaks and stellarators, is the control of the turbulent processes. The most prominent feature of turbulence in the Scrape-Off Layer (SOL), the volume between t ...

EPFL2023

Modelling of nonneutral plasmas trapped by electric and magnetic fields relevant to gyrotron electron guns

Guillaume Michel Le Bars

Gyrotrons are a class of high-power vacuum-electronics microwave sources, which are envisioned to play an important role in the domain of magnetically confined fusion plasmas. Indeed, only gyrotrons are capable of producing continuous electromagnetic waves ...

EPFL2023

Magnetic control of tokamak plasmas through deep reinforcement learning

Ambrogio Fasoli, Olivier Sauter, Basil Duval, Stefano Coda, Jean-Marc Moret, Federico Alberto Alfredo Felici, Cristian Sommariva, Antoine Pierre Emmanuel Alexis Merle, Cristian Galperti, Francesco Carpanese, Jonas Buchli, Federico Pesamosca, Brendan Tracey, Jonas Degrave

Nuclear fusion using magnetic confinement, in particular in the tokamak configuration, is a promising path towards sustainable energy. A core challenge is to shape and maintain a high-temperature plasma within the tokamak vessel. This requires high-dimensi ...

2022

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

Jonathan Graves, Jieping Zhu, Joaquim Loizu Cisquella, Eduardo Sanchez, Antoine Baillod, Mike Machielsen, Xiaoxue Han, Nicola Vianello, Jonathan Marc Philippe Faustin, Alberto Bottino, Emiliano Fable, Thomas Binderup Jensen, Attila Bencze, Michel Haas, Ajay Kumar, Shuai Liu, Hui Wang, Hartmut Zohm, Konstantinos Avramidis, Frank Rüdiger Wagner, Gregory Vogel, Sheng Xu, Adnan Ali

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

Superconductors for fusion: a roadmap

Pierluigi Bruzzone, Kamil Sedlák, Nikolay Bykovskiy, Rainer Wesche

With the first tokamak designed for full nuclear operation now well into final assembly (ITER), and a major new research tokamak starting commissioning (JT60SA), nuclear fusion is becoming a mainstream potential energy source for the future. A critical par ...

2021

Physics and applications of three-ion ICRF scenarios for fusion research

Henri Weisen, Mikhail Maslov, Javier García Hernández, Samuele Mazzi

This paper summarizes the physical principles behind the novel three-ion scenarios using radio frequency waves in the ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique ...

2021

Power exhaust by core radiation at COMPASS tokamak

Olivier Claude Martin Février, Davide Mancini

Substantial power dissipation in the edge plasma is required for the safe operation of ITER and next-step fusion reactors, otherwise unmitigated heat fluxes at the divertor plasma-facing components (PFCs) would easily exceed their material limits. Traditio ...

IOP Publishing Ltd2021

A phase-contrast-imaging core fluctuation diagnostic and first-principles turbulence modeling for JT-60SA

Stefano Coda, Stephan Brunner, Matthieu Toussaint, Aylwin Iantchenko, Kenji Tanaka

A core fluctuation diagnostic based on the phase-contrast imaging (PCI) technique has been designed for the JT-60SA tokamak, with the assistance of a synthetic diagnostic coupled to a gyrokinetic code. Using a tangentially viewing geometry, this system wou ...

IOP Publishing Ltd2021

Approaching detachment in I-mode-response of core confinement and the edge pedestal in the ASDEX Upgrade tokamak

Antoine Pierre Emmanuel Alexis Merle

Experiments on nitrogen assisted divertor detachment in the improved energy confinement mode (I-mode) are reported from the ASDEX Upgrade tokamak. When nitrogen is introduced into the divertor and radiation losses cool the divertor plasma down, a loss of c ...

IOP Publishing Ltd2021

Neutronics Analyses of EU DEMO 2020 EC Port Configuration

Minh Quang Tran, René Chavan

The DEMOnstration fusion power plant (DEMO) is being developed within EUROfusion and one of the challenges is the integration of all the systems into a fusion reactor by designs that meet strict design criteria required for safe and reliable long-term reac ...

NUCLEAR SOCIETY SLOVENIA2021

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

Assessment of alternative divertor configurations as an exhaust solution for DEMO

Holger Reimerdes, Roberto Maurizio, Seungkyu Ha, Hartmut Zohm

Plasma exhaust has been identified as a major challenge towards the realisation of magnetic confinement fusion. To mitigate the risk that the single null divertor (SND) with a high radiation fraction in the scrape-of-layer (SOL) adopted for ITER will not e ...

IOP Publishing Ltd2020

Analysis of the inter-species power balance in JET plasmas

Henri Weisen, Mikhail Maslov

Most auxiliary heating methods provide heating to more than one particle species (electrons, ions, impurities) in a fusion plasma. This can lead to substantial temperature differences between species, depending on conditions such as heating power to the di ...

IOP Publishing Ltd2020

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

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

Disruption Prediction Approaches Using Machine Learning Tools in Tokamaks

Alessandro Pau

Nuclear fusion is one of the best options to achieve a virtually limitless energy source in the future. However, sustaining burning plasma reactions is very challenging because disruptive events cause the loss of plasma confinement and damages to the tokam ...

IEEE2019