Publications associées à Classical diffusion

Equilibrium β-limits dependence on bootstrap current in classical stellarators

Jonathan Graves, Joaquim Loizu Cisquella, Antoine Baillod

While it is important to design stellarators with high magnetohydrodynamic stability β-limit, it is also crucial to ensure that good magnetic surfaces exist in a large range of β values. As β increases, pressure-driven currents perturb the vacuum magnetic ...

Cambridge University Press2023

Effect of triangularity on plasma turbulence and the SOL-width scaling in L-mode diverted tokamak configurations

Paolo Ricci, Louis Nicolas Stenger, Davide Mancini, Maurizio Giacomin

The effect of triangularity on tokamak boundary plasma turbulence is investigated using global, flux-driven, three-dimensional, two-fluid simulations. The simulations show that negative triangularity (NT) stabilizes boundary plasma turbulence, and linear i ...

IOP Publishing Ltd2023

Study of fast-ion-driven toroidal Alfvén eigenmodes impacting on the global confinement in TCV L-mode plasmas

Stefano Coda, Laurent Villard, Stephan Brunner, Justin Richard Ball, Oleg Krutkin, Luke Simons, Umesh Kumar, Baruch Rofman, Jesús Poley Sanjuán, Javier García Hernández

Following recent observations of unstable Toroidal Alfven Eigenmodes (TAEs) in a counter-current Neutral Beam Injection (NBI) scenario developed in TCV, an in-depth analysis of the impact of such modes on the global confinement and performance is carried o ...

2023

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

A new set of analytical formulae for the computation of the bootstrap current and the neoclassical conductivity in tokamaks

Olivier Sauter

A new set of analytical formulae for calculating the bootstrap current and the neoclassical conductivity in tokamak experiments is presented. Previous works comparing the widely used Sauter model with results of recently developed numerical neoclassical so ...

AMER INST PHYSICS2021

Validation of the BEAMS3D neutral beam deposition model on Wendelstein 7-X

Jonathan Graves, David Pfefferlé, Mike Machielsen, Adnan Ali, Yu Gao

The neutral beam deposition model in the BEAMS3D code is validated against neutral beam attenuation data from Wendelstein 7-X (W7-X). A set of experimental discharges where the neutral beam injection system of W7-X was utilized were reconstructed. These di ...

IOP Publishing Ltd2020

Nonlinear gyrokinetic PIC simulations in stellarators with the code EUTERPE

Laurent Villard, Eduardo Sanchez, Alberto Bottino

In this work, the first nonlinear particle-in-cell simulations carried out in a stellarator with the global gyrokinetic code EUTERPE using adiabatic electrons and realistic plasma parameters are reported. Several studies are conducted with the aim of enabl ...

Cambridge University Press2020

Ion cyclotron resonance heating scenarios for DEMO

Olivier Sauter, Ambrogio Fasoli, Yiming Li, Basil Duval, Jonathan Graves, Duccio Testa, Patrick Blanchard, Henri Weisen, Federico Nespoli, Alessandro Pau

The present paper offers an overview of the potential of ion cyclotron resonance heating (ICRH) or radio frequency heating for the DEMO machine. It is found that various suitable heating schemes are available. Similar to ITER and in view of the limited ban ...

IOP Publishing Ltd2019

Properties of a new quasi-axisymmetric configuration

Joaquim Loizu Cisquella

A novel, compact, quasi-axisymmetric configuration is presented which exhibits low fast-particle losses and is stable to ideal magnetohydrodynamic (MHD) instabilities. The design has fast-particle loss rates below 8% for flux surfaces within the half-radiu ...

IOP Publishing Ltd2019

Turbulence studies in TCV using the Correlation ECE diagnostic

Matteo Fontana

In this thesis work, the flexibility of the Tokamak à Configuration Variable (TCV) is exploited to study the influence of plasma parameters on turbulent fluctuations. The correlation electron cyclotron emission (CECE) diagnostic is used to measure low ampl ...

EPFL2018