Publications related to Plasma cutting

Scenario optimization for the tokamak ramp-down phase in RAPTOR: A. Analysis and model validation on ASDEX Upgrade

Olivier Sauter, Federico Alberto Alfredo Felici, Simon Van Mulders, Cassandre Ekta Contré, Anna Teplukhina, Bernhard Sieglin

We discuss how the combination of experimental observations and rapid modeling has enabled to improve understanding of the tokamak ramp-down phase in ASDEX Upgrade. A series of dedicated experiments has been performed, to disentangle the effect of individu ...

Iop Publishing Ltd2024

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

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

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

The effect of plasma shaping on high density H-mode SOL profiles and fluctuations in TCV

Holger Reimerdes, Benoît Labit, Christian Gabriel Theiler, Umar Sheikh, Guang-Yu Sun, Luke Simons, Nicola Vianello, Sophie Danielle Angelica Gorno, Cedric Kar-Wai Tsui, Claudia Colandrea, Adriano Stagni, Yi Wang

The impact of plasma shaping on the properties of high density H-mode scrape-off layer (SOL) profiles and transport at the outer midplane has been investigated on Tokamaka configuration variable. The experimental dataset has been acquired by evolving the u ...

IOP Publishing Ltd2024

Design Progress of Structural Components of the EU DEMO EC Equatorial Launcher

René Chavan, Jean-Philippe Hogge

The EU DEMO Tokamak is foreseen to be equipped with an electron cyclotron (EC) system for plasma heating, magnetohydrodynamic (MHD) control, and thermal instability suppression. Up to six launchers will be installed into equatorial ports with the aim to in ...

Ieee-Inst Electrical Electronics Engineers Inc2024

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

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

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

Sensitivity Analysis of the Lumped Thermal Model of the EU 170 GHz Gyrotron Magnetron Injection Gun

Jean-Philippe Hogge, Francisco Sanchez

The ITER Electron Cyclotron Resonance Heating and Current Drive (ECRH&CD) system relies on 1 MW 170 GHz Gyrotrons to provide the mm-wave power needed for plasma heating, current drive, and magneto-hydrodynamic control. The design and modeling of the contro ...

Ieee-Inst Electrical Electronics Engineers Inc2024

Studies on EU-DEMO 3D coils requirements and conceptual design for error field correction and plasma control

Pierluigi Bruzzone, Hartmut Zohm, Leonardo Pigatto

This work presents the initial studies on the requirements for the design of 3D coils on EU-DEMO. The use of 3D coils in present machines includes two main purposes: the first one is the Error Field Correction (EFC). The EFC aims at minimizing the intrinsi ...

Elsevier Science Sa2023

The MAgnet Design Explorer algorithm (MADE) for LTS, Hybrid or HTS toroidal and poloidal systems of a tokamak with a view to DEMO

The European Roadmap to Fusion Electricity (Federici et al., 2018) [1] details the path to complete within the next three decades the DEMOnstration power plant, DEMO, aiming to a net gain of Energy Q=40. The 2018 DEMO baseline considers a 2 GW tokamak devi ...

2023

Full-discharge simulation and optimization with the RAPTOR code, from present tokamaks to ITER and DEMO

Simon Van Mulders

Tokamak devices aim to magnetically confine a hydrogen plasma at sufficiently high pressure to achieve net energy production from nuclear fusion of light isotopes. Predictive modeling and optimization is crucial for reliable operation of tokamak reactors, ...

EPFL2023

A model of non-Maxwellian electron distribution function for the analysis of ECE data in JET discharges

Mikhail Maslov, Javier García Hernández, Samuele Mazzi

Recent experiments performed in JET at high level of plasma heating, in preparation of, and during the DT campaign have shown significant discrepancies between electron temperature measurements by Thomson Scattering (TS) and Electron Cyclotron Emission (EC ...

E D P SCIENCES2023

Measuring the electron energy distribution in tokamak plasmas from polarized electron cyclotron radiation

Arsène Stéphane Tema Biwole

In this doctoral thesis, a promising technique has been used for the measurement of non-thermal electrons in TCV. The technique employs a Vertical viewing ECE to more easily discriminate the radiation according to the energy of the electrons. Successful ...

EPFL2023

Impact of the plasma operation on the technical requirements in EU-DEMO

Olivier Sauter, Minh Quang Tran, Emiliano Fable, Simon Van Mulders, Hartmut Zohm

The plasma design point during stationary phase operation of EU-DEMO has been described extensively in the past, and the assumptions employed for its definition have been supported by various investigations. However, a stationary snapshot is by far not suf ...

2022

Study of impurity ion transport using charge exchange spectroscopy on TCV

Filippo Bagnato

The study of impurity transport in fusion plasmas has gained interest over the years due to its implication with tokamak performances. In TCV (Tokamak à Configuration Variable), as in many other facilities, impurity ions can be studied through the CXRS (Ch ...

EPFL2022

Modelling of sawtooth-induced fast ion transport in positive and negative triangularity in TCV

Olivier Sauter, Basil Duval, Alexander Karpushov, Duccio Testa, Mario Ludovico Podesta, Antoine Pierre Emmanuel Alexis Merle, Marcelo Baquero Ruiz, Dmytry Mykytchuk, Matteo Vallar, Lorenzo Stipani

Internal kinks are a common magneto hydro-dynamic (MHD) instability observed in tokamak operation when the q profile in the plasma core is close to unity. This MHD instability impacts both the transport of the bulk plasma (current, particle and energy tran ...

IOP Publishing Ltd2022

New insights on divertor parallel flows,E x B drifts, and fluctuations from in situ, two-dimensional probe measurement in the Tokamak a Configuration Variable

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Artur Perek, Cedric Kar-Wai Tsui, Hugo De Oliveira, Sophie Danielle Angelica Gorno

In situ, two-dimensional (2D) Langmuir probe measurements across a large part of the TCV outer divertor are reported in L-mode discharges with and without divertor baffles. This provides detailed insights into time averaged profiles, particle fluxes, and f ...

IOP Publishing Ltd2022

Femtosecond laser-shockwave induced densification in fused silica

Yves Bellouard, Pieter Vlugter, Arunkrishnan Radhakrishnan, Julien Gilles Edgar Gateau

A tightly focused femtosecond laser-beam in the non-ablative regime can induce a shockwave sufficiently intense to reach local pressures in the giga-Pascal range or more. In a single beam configuration, the location of the highest-pressure zone is nested w ...

2022

Model for current drive induced crash cycles in W7-X

Joaquim Loizu Cisquella, Ajay Kumar

In the Wendelstein 7-X (W7-X) stellarator, the vacuum rotational transform, ι, has a flat radial profile and does not cross any major rational resonance. Nevertheless, during plasma operation the ι‐profile can be strongly modified by electron cyclotron cur ...

IOP Publishing Ltd2021

Neural network surrogate of QuaLiKiz using JET experimental data to populate training space

Henri Weisen, Yann Camenen

Within integrated tokamak plasma modeling, turbulent transport codes are typically the computational bottleneck limiting their routine use outside of post-discharge analysis. Neural network (NN) surrogates have been used to accelerate these calculations wh ...

AMER INST PHYSICS2021