Publications associées à Operation Above the Greenwald Density Limit in High Performance DIII-d Negative Triangularity Discharges

Publications associées (20)

Neutral pressure measurement in TCV tokamak using ASDEX-type pressure gauges

Holger Reimerdes, Marcelo Baquero Ruiz, Guang-Yu Sun, Elena Tonello, Marc Noël, Mateusz Gospodarczyk, Hammam Elaian

Probing the neutral gas distribution at the edge of magnetic confinement fusion devices is critical for plasma exhaust studies. In the TCV tokamak, a set of ASDEX-type hot ionization pressure gauges (APGs) has been installed for fast, in situ measurements ...

2025

Plasma state monitoring and disruption characterization using multimodal VAEs

Giulio Romanelli, Olivier Sauter, Alessandro Pau, Yoeri Renier Johannes Poels, Cristina Venturini

When a plasma disrupts in a tokamak, significant heat and electromagnetic loads are deposited onto the surrounding device components. These forces scale with plasma current and magnetic field strength, making disruptions one of the key challenges for futur ...

IOP Publishing Ltd2025

Global gyrokinetic study of density gradient driven instability in tokamaks: the ubiquitous mode

Laurent Villard

The ubiquitous mode is investigated in the linear regime for the first time using a global gyrokinetic model. These modes are driven by the density gradient in trapped electron population but with mode frequency in the ion diamagnetic drift direction, in c ...

2024

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

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

Optimizing the ITER NBI ion source by dedicated RF driver test stand

Riccardo Agnello

The experimental fusion reactor ITER will feature two (or three) heating neutral beam injectors (NBI) capable of delivering 33(or 50) MW of power into the plasma. A NBI consists of a plasma source for production of negative ions (extracted negative ion cur ...

Institute of Physics2024

Overview of physics results from MAST upgrade towards core-pedestal-exhaust integration

Olivier Sauter, Holger Reimerdes, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Matteo Vallar, Samuele Mazzi

Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening understanding of key physics issues for the operation of ITER and the design of future fusion power plants. The impact of MHD instab ...

IOP Publishing Ltd2024

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

Real-time implementation of the high-fidelity NBI code RABBIT into the discharge control system of ASDEX Upgrade

Federico Alberto Alfredo Felici

For the first time, a real-time capable NBI code, which has a comparable fidelity to the much more computationally expensive Monte Carlo codes such as NUBEAM, has been coupled to the discharge control system of a tokamak. This implementation has been done ...

IOP Publishing Ltd2023

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

Development of the self-modulation instability of a relativistic proton bunch in plasma

Ambrogio Fasoli, Sun Hee Kim, Ivo Furno, Patrick Blanchard, Ana Francisca Leal Silva Soares, Yanis Andrebe, Riccardo Agnello, Samuel Rey-Mermet, Christine Stollberg, Alban Sublet

Self-modulation is a beam-plasma instability that is useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing the ratio between the initial transverse size ...

2023

On the relationship between the multi-region relaxed variational principle and resistive inner-layer theory

Joaquim Loizu Cisquella

We show that the variational energy principle of the multi-region relaxed magnetohydrodynamic (MRxMHD) model can be used to predict finite-pressure linear tearing instabilities. In this model, the plasma volume is sliced into sub-volumes separated by 'idea ...

2023

Three-dimensional inhomogeneity of electron-temperature-gradient turbulence in the edge of tokamak plasmas

Justin Richard Ball

Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has a rich three-dimensional structure, varying strongly according to the local magnetic-field configu ...

IOP Publishing Ltd2022

Overview of the TCV tokamak experimental programme

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Henri Weisen, Timothy Goodman, Yves Martin, Stefano Alberti, Duccio Testa, Jean-Marc Moret, Ivo Furno, Patrick Blanchard, Benoît Labit, Jan Horacek, Paolo Ricci, Jean-Philippe Hogge, Jonathan Graves, Stephan Brunner, Holger Reimerdes, Laurie Porte, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Alexander Karpushov, Joaquim Loizu Cisquella, Antoine Pierre Emmanuel Alexis Merle, Umar Sheikh, Xavier Llobet, Matteo Fontana, Simon Van Mulders, Alessandro Pau, Yanis Andrebe, Cristian Galperti, Joan Decker, Marcelo Baquero Ruiz, Cedric Kar-Wai Tsui, Mengdi Kong, Matteo Vallar, Olivier Claude Martin Février, Davide Galassi, Guang-Yu Sun, Pedro Andres Molina Cabrera, Filippo Bagnato, Roberto Maurizio, Oulfa Chellaï, Mirko Wensing, Claudia Colandrea, Curdin Tobias Wüthrich, Sophie Danielle Angelica Gorno, Francesco Carpanese, Nicola Offeddu, Aylwin Iantchenko, Maurizio Giacomin, Lorenzo Martinelli, Oleg Krutkin, Dahye Choi, Federico Pesamosca, Hugo Antoine Georges Arnichand, Dmytry Mykytchuk, Benjamin Alexandre Vincent, Umesh Kumar, Arsène Stéphane Tema Biwole, Lorenzo Stipani, Anna Ngoc Minh Trang Vu, Jean Arthur Cazabonne, Stefano Marchioni, Miguel Filipe Silva Füglister, Renat Karimov, Ajay Chandrarajan Jayalekshmi

The tokamak a configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its c ...

IOP Publishing Ltd2022

A novel path to runaway electron mitigation via deuterium injection and current-driven MHD instability

Cristian Sommariva

Relativistic electron (RE) beams at high current density (low safety factor, q ( a )) yet very low free-electron density accessed with D-2 secondary injection in the DIII-D and JET tokamak are found to exhibit large-scale MHD instabilities that benignly te ...

IOP Publishing Ltd2021

Controlling the rotation of drift tearing modes by biased electrode in ADITYA-U tokamak

Harshita Raj

The influence of background plasma poloidal rotation on the rotation frequency of the m/n = 2/1 drift tearing mode (DTM) has been studied in ADITYA-U tokamak. The poloidal rotation velocity of the background plasma in the ion diamagnetic direction is incre ...

2021

L-H transition threshold studies in helium plasmas at JET

Henri Weisen

We present a study of the power threshold for L-H transitions (P-LH) in almost pure helium plasmas, obtained in recent experiments at JET with an ITER-like wall (Be wall and W divertor). The most notable new result is that the density at which P-LH is mini ...

IOP Publishing Ltd2021

Effect of collisions on non-adiabatic electron dynamics in ITG-driven microturbulence

Stephan Brunner, Justin Richard Ball

Non-adiabatic electron response leads to significant changes in ion temperature gradient (ITG) eigenmodes, leading, in particular, to fine-structures that are significantly extended along the magnetic field lines at corresponding mode rational surfaces (MR ...

2021

Kinetic-MHD stability of virtually collisionless plasmas

Samuel Lanthaler

The stability of pressure driven modes such as the 1/1 internal kink is known to depend sensitively on a multitude of physical effects such as toroidal rotation, kinetic effects due to thermal and suprathermal particle species and finite Larmor radius effe ...

EPFL2020

First demonstration of real-time kinetic equilibrium reconstruction on TCV by coupling LIUQE and RAPTOR

Olivier Sauter, Jean-Marc Moret, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Cristian Galperti, Francesco Carpanese

Kinetic equilibrium reconstruction (KER) in tokamaks is the solution of the free-boundary MHD equilibrium that best fits the external magnetic measurements and the internal plasma profiles as imposed from modeling and/or available internal measurements. In ...

IOP Publishing Ltd2020

Effect of the tangential NBI current drive on the stability of pressure and energetic particle driven MHD modes in LHD plasma

Wilfred Anthony Cooper

The aim of the present study is to analyze the stability of the pressure gradient driven modes (PM) and Alfven eigenmodes (AE) in the large helical device (LHD) plasma if the rotational transform profile is modified by the current drive of the tangential n ...

IOP Publishing Ltd2020