Publications associées à Drift stabilization of ballooning modes in a high-$\langle \beta \rangle$ LHD configuration

Publications associées (41)

Helicon normal modes in radially non-uniform plasma column

Ivo Furno, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Renat Karimov

Helicon discharges are often considered somewhat mysterious, exhibiting experimental behaviors that are challenging to explain, such as abrupt plasma density jumps, hysteresis, and ‘blue core’ formation, among others. A significant part of the difficulty i ...

2025

The quasi-continuous exhaust regime in ASDEX Upgrade and JET

Olivier Sauter, Benoît Labit

The quasi-continuous exhaust (QCE) regime is a type-I ELM-free high confinement regime obtained at high plasma shaping and high separatrix density. A comparison with various ELM-free regimes in the literature is presented together with potential physics mo ...

Elsevier2025

Design and implementation of a model-based hierarchical architecture for plasma shape control in the TCV tokamak

Olivier Sauter, Stefano Coda, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Cristian Galperti, Adriano Mele, Alessandro Tenaglia

Plasma shape control is a fundamental tool for effective tokamak operation, allowing improved plasma performance and the pursuit of challenging scientific objectives. In this framework, the Tokamak á Configuration Variable (TCV) of the École Polytechnique ...

IOP Publishing2025

Turnstile flux as a measure for chaotic transport in magnetic confinement fusion devices

Ludovic Rais, Joaquim Loizu Cisquella, Christopher Berg Smiet

We analyze a measure for the degree of chaos in the magnetic fields of magnetic confinement fusion reactors by calculating the lobe fluxes of turnstiles - a method developed for characterizing transport into and out of resonance zones in Hamiltonian dynami ...

2025

Real-time density profile simulations on ASDEX Upgrade and the impact of the edge boundary condition

Olivier Sauter, Francesco Pastore

The plasma density is a crucial parameter of tokamak discharge as it impacts the fusion power, stability limits, influences detachment onset and impurities transport. The electron density profile shaping affects the deposition location of the external heat ...

Elsevier BV2025

Machine learning methods for locked-mode predictions in MAST-U plasmas

Alessandro Pau

In tokamaks, rotating magneto-hydro-dynamic modes frequently decelerate as their amplitude increases. Once a critical threshold in amplitude is reached, these modes stop rotating into a specific toroidal and poloidal position and are commonly named Locked ...

IOP Publishing Ltd2025

Investigating the influence of divertor baffles on nitrogen-seeded detachment in TCV with SOLPS-ITER simulations and TCV experiments

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Olivier Claude Martin Février, Guang-Yu Sun, Claudia Colandrea, Sophie Danielle Angelica Gorno, Luke Simons, Massimo Carpita, Elena Tonello, Richard Alexander David Ducker

Plasma edge simulations with the SOLPS-ITER code are performed to study the influence of divertor baffles on nitrogen-seeded detachment in Tokamak & agrave; Configuration Variable (TCV) single-null, L-mode discharges. Scans of nitrogen seeding rate are con ...

IOP Publishing Ltd2025

Re-design of EU DEMO with a low aspect ratio

Xabier Sarasola Martin

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, ...

Elsevier2024

Direct prediction of saturated neoclassical tearing modes in slab using an equilibrium approach

Jonathan Graves, Joaquim Loizu Cisquella, Christopher Berg Smiet, Erol Balkovic

We demonstrate for the first time that the nonlinear saturation of neoclassical tearing modes (NTMs) can be found directly using a variational principle based on Taylor relaxation, without needing to simulate the intermediate, resistivity-dependent dynamic ...

IOP Publishing2024

Full-F turbulent simulation in a linear plasma device using a gyro-moment approach

Paolo Ricci, Baptiste Jimmy Frei

Simulations of plasma turbulence in a linear plasma device configuration are presented. These simulations are based on a simplified version of the gyrokinetic (GK) model proposed by Frei et al. [J. Plasma Phys. 86, 905860205 (2020)], where the full-F distr ...

Aip Publishing2024

Global fluid simulation of plasma turbulence in stellarators with the GBS code

Paolo Ricci, Joaquim Loizu Cisquella, António João Caeiro Heitor Coelho, Zeno Tecchiolli

The implementation of three-dimensional magnetic fields, such as the ones of stellarators, in the GBS code (Ricci et al 2012 Plasma Phys. Control. Fusion54 124047; Giacomin et al 2022 J. Comput. Phys.464 111294) is presented, and simulation results are dis ...

IOP Publishing Ltd2024

Gyrokinetic simulations of turbulence in magnetic fusion plasmas using a delta-f PIC scheme with evolving background

Moahan Murugappan

Using the GKEngine code which simulates an electrostatic plasma with adiabatic electron response under a sheared-slab geometry, an attempt at developing a hybrid approach between the delta-f and full-f schemes to describe plasma profiles exhibiting high fl ...

EPFL2024

Interplay of plasma resistivity and rotation on β limits in free boundary diverted tokamaks

Jonathan Graves

A plasma resistivity-β driving mechanism aimed at explaining the appearance of long wavelength global instabilities in free boundary high-β tokamak plasmas with a divertor is presented. These perturbations resemble very closely the resistive wall mode phen ...

2024

Iterative removal of sources to model the turbulent electromotive force

Salim Bennouna, Abhijit Bhausaheb Bendre

We describe a novel method to compute the components of dynamo tensors from direct magnetohydrodynamic (MHD) simulations. Our method relies upon an extension and generalization of the standard H & ouml;gbom CLEAN algorithm widely used in radio astronomy to ...

Oxford Univ Press2024

Scenario optimization for the tokamak ramp-down phase in RAPTOR. Part B: safe termination of DEMO plasmas

Olivier Sauter, Federico Alberto Alfredo Felici, Emiliano Fable, Anna Teplukhina, Simon Van Mulders, Cassandre Ekta Contré

An optimized plasma current ramp-down strategy is critical for safe and fast termination of plasma discharges in a tokamak demonstration fusion reactor (DEMO), both in planned and emergency scenarios, avoiding plasma disruptions and excessive heat loads to ...

Iop Publishing Ltd2024

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

Global fluid simulations of plasma turbulence in stellarators

António João Caeiro Heitor Coelho

In order to cope with the decarbonization challenge faced by many countries, fusion is one of the few alternatives to fossil fuels for the production of electricity. Two devices invented in the middle of the previous century have emerged as the most promis ...

EPFL2024

Equilibrium pressure limits in stellarators

Antoine Baillod

This thesis delves into the potential of magnetic fusion energy, and in particular focuses on the stellarator concept. Stellarators use external coils to produce 3-dimensional (3D) magnetic fields that confine a thermonuclear plasma in a topologically toro ...

EPFL2023

Benign termination of runaway electron beams on ASDEX Upgrade and TCV

Stefano Coda, Basil Duval, Joan Decker, Umar Sheikh, Claudia Colandrea, Luke Simons, Jean Arthur Cazabonne

This paper discusses the development of a benign termination scenario for runaway electron (RE) beams on ASDEX Upgrade and TCV. A systematic study revealed that a low electron density (n e) companion plasma was required to achieve a large MHD instability, ...

Iop Publishing Ltd2024

Exploration of the parameter space for the excitation and saturation of Edge Harmonic Oscillations

Guillermo Bustos Ramirez

This thesis presents advancements in the understanding of the plasma conditions leading to the excitation and saturation of the Edge Harmonic Oscillations (EHOs) observed during QH-mode operation in tokamak plasmas. Such operations represent a safer altern ...

EPFL2023