Publications de Stefano Coda | EPFL Graph Search

Modelling of ETG turbulent transport in the TCV pedestal

Stephan Brunner, Stefano Coda, Benoît Labit, Oleg Krutkin

Results of the first gyrokinetic simulations of the TCV pedestal are presented. Two discharges at varying levels of gas puffing are considered as input parameters for the local GENE simulations. Linear and nonlinear simulations are carried out for electron ...

2025

Milestone in predicting core plasma turbulence: successful multi-channel validation of the gyrokinetic code GENE

Basil Duval, Timothy Goodman, Olivier Sauter, Stefano Coda, Laurie Porte, Benoît Labit, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Umar Sheikh, Mengdi Kong, Simon Van Mulders, Cristian Sommariva, Alessandro Pau

On the basis of several recent breakthroughs in fusion research, many activities have been launched around the world to develop fusion power plants on the fastest possible time scale. In this context, high-fidelity simulations of the plasma behavior on lar ...

2025

An upper pressure limit for low-Z benign termination of runaway electron beams in TCV

Basil Duval, Holger Reimerdes, Stefano Coda, Joan Decker, Umar Sheikh, Claudia Colandrea, Luke Simons

We present a model for the particle balance in the post-disruption runaway electron plateau phase of a tokamak discharge. The model is constructed with the help of, and applied to, experimental data from TCV discharges investigating the so-called 'low-Z be ...

IOP Publishing Ltd2025

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

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

Implementation of an Iter-relevant Qp-based Current Limit Avoidance Algorithm in the Tcv Tokamak

Stefano Coda, Cristian Galperti

The problem of avoiding saturation of the coil currents is critical in large tokamaks with superconducting coils like ITER. Indeed, if the current limits are reached, a loss of control of the plasma may lead to a major disruption. Therefore, a current limi ...

IOP Publishing Ltd2025

Nonlinear excitation of energetic particle driven geodesic acoustic mode by resonance overlap with Alfvén instability in ASDEX Upgrade

Basil Duval, Timothy Goodman, Olivier Sauter, Stefano Coda, Laurie Porte, Benoît Labit, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Umar Sheikh, Mengdi Kong, Simon Van Mulders, Cristian Sommariva, Alessandro Pau

The Alfvén instability nonlinearly excited the energetic-particle-driven geodesic acoustic mode on the ASDEX-Upgrade tokamak, as demonstrated experimentally. The mechanism of the energetic-particle-driven geodesic acoustic mode excitation and the mode nonl ...

Nature Research2025

Survey of the Edge Radial Electric Field in L-mode Tcv Plasmas Using Doppler Backscattering

Stefano Coda, Benoît Labit

A Doppler backscattering (DBS) diagnostic has recently been installed on the Tokamak & agrave; Configuration Variable (TCV) to facilitate the study of edge turbulence and flow shear in a versatile experimental environment. The dual channel V-band DBS syste ...

IOP Publishing Ltd2025

Isotope effects in linear and saturated ohmic confinement of TCV tokamak and gyrokinetic validation

Basil Duval, Olivier Sauter, Henri Weisen, Stefano Coda, Alexander Karpushov, Benoît Labit, Lorenzo Martinelli, Dmytry Mykytchuk, Oleg Krutkin, Artur Perek

We investigated isotope effects during the tokamak à configuration variable (TCV) ohmic discharge of a diverted positive triangular shape configuration of deuterium (D) and hydrogen (H) plasmas. The transition from the linear ohmic confinement (LOC) regime ...

2025

Effect of energetic ions on edge-localized modes in tokamak plasmas

Patrick Blanchard, Timothy Goodman, Jean-Marc Moret, Olivier Sauter, Holger Reimerdes, Stefano Coda, Alexander Karpushov, Yanis Andrebe, Duccio Testa, Benoît Labit, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Hugo De Oliveira, Claudio Marini, Antoine Pierre Emmanuel Alexis Merle, Anna Teplukhina, Joan Decker, Cedric Kar-Wai Tsui, Umar Sheikh, Cristian Galperti, Kevin Henricus Annemarie Verhaegh, Dahye Choi, Aylwin Iantchenko, Mengdi Kong, Roberto Maurizio, Francesco Carpanese, Mirko Wensing, Lorenzo Stipani, Federico Pesamosca, Olivier Claude Martin Février, Filippo Bagnato, Cristian Sommariva, Davide Galassi

The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is the high-confinement mode. In this regime, however, periodic relaxations of the plasma edge can occur. These edge-localized modes pose a ...

2025

Nonlinear Effects in Fluctuation Short Pulse Reflectometry

Stephan Brunner, Stefano Coda, Oleg Krutkin

The fluctuation short pulse reflectometry diagnostic is simulated with the full-wave CUWA code for ad-hoc turbulence and simplified geometry. The nonlinear effects on the measurements are investigated while accounting for the plasma curvature, probing angl ...

IOP Publishing Ltd2025

Present status of heating neutral beam injection system at TCV

Patrick Blanchard, Basil Duval, Damien Fasel, Ambrogio Fasoli, Yves Martin, Olivier Sauter, Stefano Coda, Ugo Siravo, Alexander Karpushov, Yanis Andrebe, Jérémie Dubray, Frédéric Dolizy, Rémy Jacquier, Matthieu Toussaint, Dmytry Mykytchuk

The paper describes the operation and upgrade of the Heating Neutral Beam Injection (HNBI) system as well as the related infrastructure at the Tokamak Configuration Variable (TCV) during the last years. In 2023, the installation of new TCV neutron shieldin ...

2025

Tangentially viewing phase contrast imaging for turbulence measurements in toroidal fusion devices

Stefano Coda

Phase contrast imaging (PCI) is an established and powerful technique for measuring density fluctuations in plasmas and has been successfully applied to several fusion devices. Rooted in a concept first developed for microscopy, PCI belongs to the category ...

2024

Dynamic steady-state coil current allocation for plasma shape control: A study on the TCV tokamak

Stefano Coda, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle

This work addresses the input current allocation problem for the magnetic control system of the Tokamak à Configuration Variable (TCV). Given the available actuators (i.e. poloidal field coils) on the TCV device, this work aims to optimize the input curren ...

Institute of Electrical and Electronics Engineers Inc.2024

Progress in the development of the ITER baseline scenario in TCV

Olivier Sauter, Stefano Coda, Alexander Karpushov, Yann Camenen, Benoît Labit, Antoine Pierre Emmanuel Alexis Merle, Olivier Claude Martin Février, Simon Van Mulders, Filippo Bagnato, Alessandro Pau, Matteo Vallar, Cassandre Ekta Contré, Stefano Marchioni, Oleg Krutkin, Reinart Andreas J. Coosemans

Under the auspices of EUROfusion, the ITER baseline (IBL) scenario has been jointly investigated on AUG and TCV in the past years and this paper reports on the developments on TCV. It is found that the performance of TCV IBL is mainly limited by (neoclassi ...

2024

Study of impurity C transport and plasma rotation in negative triangularity on the TCV tokamak

Basil Duval, Olivier Sauter, Stefano Coda, Alexander Karpushov, Laurie Porte, Benoît Labit, Antoine Pierre Emmanuel Alexis Merle, Justin Richard Ball, Filippo Bagnato, Alessandro Pau, Dmytry Mykytchuk

Carbon impurity transport is studied in the TCV tokamak using a charge exchange recombination diagnostic. TCVs flexible shaping capabilities were exploited to extend previous impurity transport studies to negative triangularity (delta < 0). A practical way ...

Iop Publishing Ltd2024

Comparison of detachment in Ohmic plasmas with positive and negative triangularity

Basil Duval, Olivier Sauter, Holger Reimerdes, Stefano Coda, Laurie Porte, Christian Gabriel Theiler, Olivier Claude Martin Février, Garance Hélène Salomé Durr-Legoupil-Nicoud, Sophie Danielle Angelica Gorno, Claudia Colandrea, Artur Perek

In recent years, negative triangularity (NT) has emerged as a potential high-confinement L-mode reactor solution. In this work, detachment is investigated using core density ramps in lower single null Ohmic L-mode plasmas across a wide range of upper, lowe ...

Iop Publishing Ltd2024

Automated shot-to-shot optimization of the plasma start-up scenario in the TCV tokamak

Basil Duval, Stefano Coda, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Curdin Tobias Wüthrich, Pedro Andres Molina Cabrera, Cristian Galperti, Artur Perek

Plasma start-up is typically achieved manipulating poloidal magnetic fields, gas injection and possibly auxiliary heating. Model-based design techniques have been gaining increasing attention in view of future large tokamaks which have more stringent const ...

IOP Publishing Ltd2024

Experiments and gyrokinetic simulations of TCV plasmas with negative triangularity in view of DTT operations

Olivier Sauter, Stefano Coda, Alberto Mariani, Justin Richard Ball, Filippo Bagnato, Matteo Vallar

Negative triangularity (NT) scenarios in TCV have been compared to positive triangularity (PT) scenarios using the same plasma shapes foreseen for divertor tokamak test tokamak operations. The experiments provided a NT/PT L-mode pair and a PT H-mode with d ...

Iop Publishing Ltd2024

DIII-D research to provide solutions for ITER and fusion energy

Olivier Sauter, Stefano Coda

The DIII-D tokamak has elucidated crucial physics and developed projectable solutions for ITER and fusion power plants in the key areas of core performance, boundary heat and particle transport, and integrated scenario operation, with closing the core-edge ...

IOP Publishing Ltd2024

Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas

Stefano Coda, Justin Richard Ball

In this work, we study the impact of aspect ratio A = R 0 / r (the ratio of major radius R 0 to minor radius r) on the confinement benefits of negative triangularity (NT) plasma shaping. We use high-fidelity flux tube gyrokinetic GENE simulations and consi ...

Iop Publishing Ltd2024