Publications associées à Toroidal and poloidal coordinates

Shedding light on the MRI-driven dynamo in a stratified shearing box

We study the magneto-rotational instability (MRI) dynamo in a geometrically thin disc (H/R < 1) using stratified zero net (vertical) flux shearing box simulations. We find that mean fields and electromotive forces (EMFs) oscillate with a primary frequency ...

2024

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

DEMO toroidal field coil fast discharge unit integration studies

Roberto Guarino, Alberto Ferro

The Fast Discharge Units (FDUs) of the Superconducting (SC) Toroidal Field (TF) coils in the European demonstration fusion power plant DEMO warrant the machine integrity over its full lifetime against severe failure events, such as SC coil quenches or any ...

Elsevier Science Sa2024

Occam's razor on the mechanism of resistive-wall-mode-induced beta limits in diverted tokamaks

Jonathan Graves, Daniele Brunetti

External kink modes, believed to be the drive of the 0-limiting resistive wall mode, are strongly stabilized by the presence of a separatrix. We thus propose a novel mechanism explaining the appearance of long-wavelength global instabilities in free bounda ...

2023

Excitation of toroidal Alfvén eigenmodes with counter-current NBI in the TCV tokamak

Laurie Porte, Matteo Vallar, Alexander Karpushov, Samuele Mazzi

In TCV, unstable modes excited by resonant interaction between the shear Alfvèn waves in con- tinuum gaps and energetic particles have been observed in scenarios with Neutral Beam Injection (NBI). TCV is a middle-size device (R 0 /a = 0.88/0.25) equipped w ...

IOP Publishing Ltd2023

Nonlinear interaction of Alfvénic instabilities and turbulence via the modification of the equilibrium profiles

Laurent Villard, Alberto Bottino, Xiao Wang

Nonlinear simulations of Alfvén modes (AMs) driven by energetic particles (EPs) in the presence of turbulence are performed with the gyrokinetic particle-in-cell code ORB5. The AMs carry a heat flux, and consequently they nonlinearly modify the plasma temp ...

Cambridge University Press2023

Vertical electron cyclotron emission diagnostic on the tokamak à configuration variable

Ambrogio Fasoli, Stefano Coda, Laurie Porte

In this paper, a diagnostic for the measurement of the electron cyclotron emission (ECE) from non-thermal electrons in magnetically confined fusion plasmas is presented. The diagnostic employs a vertical viewing line of sight that allows us to directly inf ...

2023

The role of isotope mass and transport for H-mode access in tritium containing plasmas at JET with ITER-like wall

Henri Weisen, Haomin Sun, Javier García Hernández, Marco Wischmeier, Nicola Vianello, Mikhail Maslov

The required heating power, P-LH, to access the high confinement regime (H-mode) in tritium containing plasmas is investigated in JET with ITER-like wall at a toroidal magnetic field of B-t = 1.8 T and a plasma current of I-p = 1.7 MA. PLH, also referred t ...

IOP Publishing Ltd2023

AC loss and electrical resistance of the RW3 diffusion-bonded joint

Vincenzo D'Auria

For the European DEMO fusion reactor, several options of the Toroidal Field (TF) coil design were proposed. The winding of the TF coil option 1 is based on React&Wind (RW), Nb3Sn, graded conductors in order to optimize the amount of superconductor accordin ...

2023

Optimization of X-mode electron cyclotron current drive in high-electron-temperature plasma in the EAST tokamak

Joan Decker, Chunmin Zhang, Fang Liu

A discharge with electron temperature up to 14 keV has been achieved in EAST. Analysis of the electron cyclotron current drive (ECCD) efficiency at high electron temperature under EAST parameters is presented using C3PO/LUKE code. Simulation results show t ...

2023

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

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

The JET hybrid scenario in Deuterium, Tritium and Deuterium-Tritium

Matteo Fontana, Haomin Sun, Javier García Hernández, Mikhail Maslov

The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with the ITER-like Be/W wall. The development started in pure Deuterium with refinement of the plasm ...

IOP Publishing Ltd2023

Linear and nonlinear excitation of TAE modes by external electromagnetic perturbations using ORB5

Laurent Villard, Emmanuel Lanti, Alberto Bottino, Mohsen Sadr

The excitation of toroidicity-induced Alfven eigenmodes (TAEs) using prescribed external electromagnetic perturbations (hereafter 'antenna') acting on a confined toroidal plasma, as well as its nonlinear couplings to other modes in the system, is studied. ...

IOP Publishing Ltd2022

Validation of edge turbulence codes against the TCV-X21 diverted L-mode reference case

Paolo Ricci, Holger Reimerdes, Christian Gabriel Theiler, Nicola Vianello, Davide Galassi, Cedric Kar-Wai Tsui, Hugo De Oliveira, Maurizio Giacomin, Sophie Danielle Angelica Gorno, Eric Serre, Claudia Colandrea, Nicola Offeddu

Self-consistent full-size turbulent-transport simulations of the divertor and scrape-off-layer (SOL) of existing tokamaks have recently become feasible. This enables the direct comparison of turbulence simulations against experimental measurements. In this ...

IOP Publishing Ltd2022

Feasibility Study of GaToroid Gantries for Carbon Ions

Bertrand Dutoit, Luca Bottura, Enrico Felcini, Bertrand Dutoit

The use of carbon ions in particle therapy can enhance the treatment quality, introducing higher biological effectiveness compared to photons and protons. Rotating gantries are nowadays used to deliver particle beams from different directions to obtain pre ...

IEEE Institute of Electrical and Electronics Engineers2022

Global fluid simulation of plasma turbulence in a stellarator with an island divertor

Paolo Ricci, Joaquim Loizu Cisquella, Maurizio Giacomin, António João Caeiro Heitor Coelho

Results of a three-dimensional, flux-driven, electrostatic, global, two-fluid turbulence simulation for a five-field period stellarator with an island divertor are presented. The numerical simulation is carried out with the GBS code, recently extended to s ...

IOP Publishing Ltd2022

Numerical study of delta-function current sheets arising from resonant magnetic perturbations

Joaquim Loizu Cisquella, Yao Zhou

General three-dimensional toroidal ideal magnetohydrodynamic equilibria with a continuum of nested flux surfaces are susceptible to forming singular current sheets when resonant perturbations are applied. The presence of singular current sheets indicates t ...

2022

Turbulent transport regimes in the tokamak boundary

Maurizio Giacomin

The overall performance of a tokamak strongly depends on phenomena that take place in a thin region between the main plasma and the vessel wall, which is denoted as tokamak boundary. In fact, the formation of transport barriers in this region can significa ...

EPFL2022

Computation of multi-region, relaxed magnetohydrodynamic equilibria with prescribed toroidal current profile

Jonathan Graves, Joaquim Loizu Cisquella, Antoine Baillod, Ajay Kumar

The stepped-pressure equilibrium code (SPEC) (Hudson et al., Phys. Plasmas, vol. 19, issue 11, 2012, 112502) is extended to allow the computation of multi-region, relaxed magnetohydrodynamics (MRxMHD) equilibria at prescribed toroidal current profile. Toro ...

Cambridge University Press2021