Publications related to Characterization of plasmas in negative ion sources using a Cs-H Collisional Radiative model

Related publications (27)

Impurity-seeded detachment in conventional and optimized TCV divertor geometry

Nuclear fusion provides a potentially unlimited and clean energy source which motivates the development of fusion power plants. The tokamak is one of the most promising concepts for a future reactor, confining the fusion plasmas in a torus using strong mag ...

EPFL2025

X-point radiation: From discovery to potential application in a future reactor

Holger Reimerdes, Christian Gabriel Theiler, Umar Sheikh, Olivier Claude Martin Février

Power exhaust is a crucial issue for future fusion reactors. Divertor detachment and the required power dissipation fractions of about 95% are foreseen to be achieved by impurity seeding. In a tokamak, at high seeding levels the radiation often concentrate ...

Elsevier2025

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

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

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

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

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

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

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

Investigation of scrape-off layer and divertor transport using infrared thermography and SOLPS-ITER simulations

Claudia Colandrea

Nuclear fusion, with its potential to provide a nearly unlimited energy source, has inspired scientists to work on the development of fusion power plants. Among the various devices designed to harness nuclear fusion, the tokamak confines the fusion fuel, w ...

EPFL2024

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

Olivier Sauter, Emiliano Fable, Federico Alberto Alfredo Felici, 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

Isotope effects and Alfvén eigenmode stability in JET H, D, T, DT, and He plasmas

Ambrogio Fasoli

While much about Alfvén eigenmode (AE) stability has been explored in previous and current tokamaks, open questions remain for future burning plasma experiments, especially regarding exact stability threshold conditions and related isotope effects; the lat ...

IOP Publishing Ltd2024

Validating reduced models for detachment onset and reattachment times on MAST-U

Holger Reimerdes

Two reduced models for predicting detachment onset and divertor reattachment times are validated on MAST Upgrade (MAST-U). These models are essential for future tokamak reactor design, providing rapid calculations based primarily on engineering parameters. ...

Elsevier2024

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

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

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, Elena Tonello, Massimo Carpita, Artur Perek, Emanuel Paul Huett, Martim Zurita

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

Experimental validation of momentum transport theory in the core of H-mode plasmas in the ASDEX Upgrade tokamak

Basil Duval

This study employs the established momentum transport analysis at ASDEX Upgrade [Zimmermann et al., Nucl. Fusion 63, 124003 (2023)] to investigate the parametric variations of the momentum transport coefficients in the core of H-mode plasmas. These experim ...

Aip Publishing2024

Quench Detection and Temperature Measurement With Fiber Optic Sensors

Davide Uglietti, Kamil Sedlák

For the EU DEMO conductor testing, a temperature sensor based on Fiber Bragg Grating (FBG) optical fiber is studied at the EPFL Swiss Plasma Center. The SULTAN test facility has been upgraded to use fiber optic sensor for temperature monitoring and quench ...

IEEE Institute of Electrical and Electronics Engineers2024

Numerical study of fully baffled Super-X L-mode discharges on TCV

Christian Gabriel Theiler, Davide Galassi

We present a numerical study of three fully baffled L-mode TCV discharges with three different values of the outer strike-point major radius/total flux expansion, showing that the beneficial effect of large strike point radius is partially screened in thes ...

Elsevier2023

4D and 5D phase-space tomography using slowing-down physics regularization

Marcelo Baquero Ruiz, Dmytry Mykytchuk, Jacob Emil Mencke

We compute reconstructions of 4D and 5D fast-ion phase-space distribution functions in fusion plasmas from synthetic projections of these functions. The fast-ion phase-space distribution functions originating from neutral beam injection (NBI) at TCV and We ...

IOP Publishing Ltd2023

Investigating the impact of the molecular charge-exchange rate on detached SOLPS-ITER simulations

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Kevin Henricus Annemarie Verhaegh

Plasma-molecular interactions generate molecular ions which react with the plasma and contribute to detachment through molecular activated recombination (MAR), reducing the ion target flux, and molecular activated dissociation (MAD), both of which create e ...

IOP Publishing Ltd2023

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

Olivier Sauter, Alessandro Pau

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

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