Publications associées à A drift-kinetic Semi-Lagrangian 4D code for ion turbulence simulation

Global fluid simulation of plasma turbulence in stellarators with the GBS code

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

The implementation of three-dimensional magnetic fields, such as the ones of stellarators, in the GBS code (Ricci et al 2012 Plasma Phys. Control. Fusion54 124047; Giacomin et al 2022 J. Comput. Phys.464 111294) is presented, and simulation results are dis ...

IOP Publishing Ltd2024

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

Joaquim Loizu Cisquella, Paolo Ricci, 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

Modeling of saturated external MHD instabilities in tokamaks: A comparison of 3D free boundary equilibria and nonlinear stability calculations

Jonathan Graves

3D free boundary equilibrium computations have recently been used to model external kinks and edge harmonic oscillations (EHOs), comparing with linear MHD stability codes, and nonlinear analytic theory [Kleiner et al., Phys. Plasma Controlled Fusion 61, 08 ...

2022

Vlasov simulation of the emissive plasma sheath with energy-dependent secondary emission coefficient and improved modeling for dielectric charging effects

Guang-Yu Sun

A one-dimensional Vlasov-Poisson simulation code is employed to investigate the plasma sheath considering electron-induced secondary electron emission (SEE) and backscattering. The SEE coefficient is commonly treated as constant in a range of plasma simula ...

FRONTIERS MEDIA SA2022

Moving toward mass-conserving simulations of plasma turbulence and kinetic neutrals in the tokamak boundary with the GBS code

Paolo Ricci

A model for the simulation of the tokamak boundary is described, which is mass-conserving to leading order in rho s / R 0 (where rho s is the ion sound Larmor radius and R-0 is the tokamak major radius at the magnetic axis). The model integrates a three-di ...

2021

The Alfvenic nature of chromospheric swirls

Andrea Francesco Battaglia, Aleksi Antoine Bossart

Context. Observations show that small-scale vortical plasma motions are ubiquitous in the quiet solar atmosphere. They have received increasing attention in recent years because they are a viable candidate mechanism for the heating of the outer solar atmos ...

EDP SCIENCES S A2021

Development of free-boundary equilibrium and transport solvers for simulation and real-time interpretation of tokamak experiments

Francesco Carpanese

To exploit fusion as a source of energy, a hot and dense confined plasma is needed. This is achieved in tokamaks by actively controlling the plasma state meaning shape, position and internal kinetic profiles. This thesis addresses two topics: the developme ...

EPFL2021

Self-consistent simulation of multi-component plasma turbulence and neutral dynamics in the tokamak boundary

André Calado Coroado

The interaction between neutral particles and the plasma plays a key role in determining the dynamics of the tokamak boundary that, in turn, significantly impact the overall performance of the device. Leveraging the work in Wersal and Ricci [Nucl. Fusion 5 ...

EPFL2021

Shaping effects on scrape-off layer plasma turbulence: A rigorous validation of three-dimensional simulations against TCV measurements

Paolo Ricci, Fabio Riva, Cedric Kar-Wai Tsui

The effect of plasma shaping on scrape-off layer (SOL) plasma turbulence is investigated through a rigorous validation exercise. Two- and three-dimensional simulations of the SOL plasma dynamics in three TCV limited discharges are carried out with the GBS ...

American Institute of Physics (AIP)2020

Experimental analysis of suprathermal electrons generated by electron cyclotron waves in tokamak plasmas

Dahye Choi

This thesis focuses on the physics of suprathermal electrons generated by electron cyclotron (EC) waves in tokamak plasmas, which play an important role in the physics of current drive and energetic particle-driven instabilities. The suprathermal electron ...

EPFL2020

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

Wilfred Anthony Cooper, Joao Varela

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

Four-dimensional drift-kinetic model for scrape-off layer plasmas

Paolo Ricci, Rogério Manuel Cabete De Jesus Jorge

A four-dimensional plasma model able to describe the scrape-off layer region of tokamak devices at arbitrary collisionality is derived in the drift-reduced limit. The basis of the model is provided by a drift-kinetic equation that retains the full nonlinea ...

2020

Chiral fermion asymmetry in high-energy plasma simulations

Jennifer Waltraud Schober

The chiral magnetic effect (CME) is a quantum relativistic effect that describes the appearance of an additional electric current along a magnetic field. It is caused by an asymmetry between the number densities of left- and right-handed fermions, which ca ...

2020

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 principles gyrokinetic analysis of electromagnetic plasma instabilities

Stephan Brunner, Laurent Villard, Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana

A two-fold analysis of electromagnetic core tokamak instabilities in the framework of the gyrokinetic theory is presented. First principle theoretical foundations of the gyrokinetic theory are used to explain and justify the numerical results obtained with ...

2019

Simulation of plasma turbulence in the periphery of diverted tokamak by using the GBS code

Paolo Ricci, Fabio Riva, Baptiste Jimmy Frei, Christoph Wersal, Paola Paruta, Carrie Fiona Beadle

We report on the implementation of diverted magnetic equilibria in GBS and on first simulations in this geometry. GBS is a simulation code used to evolve plasma turbulence in the tokamak periphery by solving the drift-reduced Braginskii's equations. The mo ...

2018

H- ion source for CERN's Linac4 accelerator : simulation, experimental validation and optimization of the hydrogen plasma

Stefano Mattei

Linac4 is the new negative hydrogen ion (H-) linear accelerator of the European Organization for Nuclear Research (CERN). Its ion source operates on the principle of Radio-Frequency Inductively Coupled Plasma (RF-ICP) and it is required to provide 50 mA of ...

EPFL2017

A 3D MHD equilibrium description of nonlinearly saturated ideal external kink/peeling structures in tokamaks

Wilfred Anthony Cooper, Basil Duval, Olivier Sauter, Trach-Minh Tran, Holger Reimerdes, Laurie Porte, Jonathan Graves

Novel free boundary magnetohydrodynamic equilibrium states with spontaneous three-dimensional (3-D) deformations of the plasmaâ vacuum interface are computed. The structures obtained look like saturated ideal external kink/peeling modes. Large edge pre ...

Cambridge University Press2015

Hybrid guiding-centre/full-orbit simulations in non-axisymmetric magnetic geometry exploiting general criterion for guiding-centre accuracy

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé

To identify under what conditions guiding-centre or full-orbit tracing should be used, an estimation of the spatial variation of the magnetic field is proposed, not only taking into account gradient and curvature terms but also parallel currents and the lo ...

Iop Publishing Ltd2015

Guiding-centre transformation of the radiation-reaction force in a non-uniform magnetic field

Joan Decker

In this paper, we present the guiding-centre transformation of the radiation reaction force of a classical point charge travelling in a non-uniform magnetic field. The transformation is valid as long as the gyroradius of the charged particles is much small ...

Cambridge University Press2015