Publications de Thibaut Vernay

Orb5: A global electromagnetic gyrokinetic code using the PIC approach in toroidal geometry

Stephan Brunner, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Thibaut Vernay, Ben McMillan, Emmanuel Lanti, Julien Stanislas Pierre Dominski, Noé Thomas Elie Ohana, Aaron Lewis Scheinberg, Claudio Gheller

This paper presents the current state of the global gyrokinetic code Orb5 as an update of the previous reference (Jolliet et al., 2007). The Orb5 code solves the electromagnetic Vlasov–Maxwell system of equations using a PIC scheme and also includes collis ...

2019

Complete multi-field characterization of the geodesic acoustic mode in the TCV tokamak

Stephan Brunner, Laurent Villard, Stefano Coda, Laurie Porte, Thibaut Vernay, Cornelis Adrianus de Meijere, Julien Stanislas Pierre Dominski, Zhouji Huang, Gabriele Merlo

The geodesic acoustic mode (GAM) is a coherently oscillating zonal flow that may regulate turbulence in toroidal plasmas. Uniquely, the complete poloidal and toroidal structure of the magnetic component of the turbulence-driven GAM has been mapped in the T ...

Iop Publishing Ltd2014

Global Gyrokinetic Simulations of TEM Microturbulence

Stephan Brunner, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

Institute of Physics2013

Global Gyrokinetic ITG Turbulence Simulations of ITER

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Thibaut Vernay, Ben McMillan

Global gyrokinetic simulations of ion temperature gradient (ITG) driven turbulence in an ideal MHD ITER equilibrium plasma are performed with the ORB5 code. The noise control and field-aligned Fourier filtering procedures implemented in ORB5 are essential ...

Institute of Physics2013

Collisions in Global Gyrokinetic Simulations of Tokamak Plasmas using the Delta-f Particle-In-Cell Approach : Neoclassical Physics and Turbulent Transport

Thibaut Vernay

The present work takes place within the general context of research related to the development of nuclear fusion energy. More specifically, this thesis is mainly a numerical and physical contribution to the understanding of turbulence and associated transp ...

EPFL2013

Synergy between ion temperature gradient turbulence and neoclassical processes in global gyrokinetic particle-in-cell simulations

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

Based on the CYCLONE case, simulations of collisional electrostatic ion temperature gradient (ITG) microturbulence carried out with the global gyrokinetic particle-in-cell (PIC) code ORB5 are presented. Considering adiabatic electrons, an increase in ion h ...

American Institute of Physics (AIP)2012

Gyrokinetic transport relations for gyroscale turbulence

Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

We derive explicit local transport relations for the global gyrokinetic formalism at arbitrary wavelength. This is an extension of the analysis in Scott et. al. 2010 where this was examined in the long-wavelength limit. Deriving a local expression for the ...

IOP Publishing2012

Parallel filtering in global gyrokinetic simulations

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Thibaut Vernay, Ben McMillan

In this work, a Fourier solver [B.F. McMillan, S. Jolliet, A. Bottino, P. Angelino, T.M. Tran, L Villard, Comp. Phys. Commun. 181 (2010) 7151 is implemented in the global Eulerian gyrokinetic code GT5D [Y. Idomura, H. Urano, N. Aiba, S. Tokuda, Nucl. Fusio ...

Elsevier2012

Interaction of large scale flow structures with gyrokinetic turbulence

Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

Shear flows have a profound influence on turbulence-driven transport in tokamaks. The introduction of arbitrary initial flow profiles into the code ORB5 [Jolliet et al., Comput. Phys. Commun. 177, 409 (2007)] allows the convenient study of how flows on all ...

American Institute of Physics2011

Global simulations of tokamak microturbulence: finite beta effects and collisions

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

In this paper, we present global nonlinear gyrokinetic simulations including finite beta effects and collisions in tokamak geometry. Global electromagnetic simulations using conventional delta-f particle in cell methods are very demanding, with respect to ...

Institute of Physics2011

Global Nonlinear Electromagnetic Simulations of Tokamak Turbulence

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

The particle-in-cell code ORB5 is a global gyrokinetic turbulence simulation code in tokamak geometry. It has been developed at CRPP, Lausanne, Switzerland, with major contributions from IPP, Garching, Germany, and IPP, Greifswald, Germany, under a long-st ...

Institute of Electrical and Electronics Engineers2010

Gyrokinetic simulations of turbulent transport: size scaling and chaotic behaviour

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Xavier Lapillonne, Ben McMillan

Important steps towards the understanding of turbulent transport have been made with the development of the gyrokinetic framework for describing turbulence and with the emergence of numerical codes able to solve the set of gyrokinetic equations. This paper ...

IOP Publishing2010

Neoclassical equilibria as starting point for global gyrokinetic microturbulence simulations

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Jonathan Graves, Thibaut Vernay, Ben McMillan

The implementation of linearized operators describing inter- and like-species collisions in the global gyrokinetic particle-in-cell code ORB5 [ S. Jolliet, Comput. Phys. Commun. 177, 409 (2007) ] is presented. A neoclassical axisymmetric equilibrium with s ...

American Institute of Physics2010

Global collisional gyrokinetic simulations of ITG microturbulence starting from a neoclassical equilibrium

Stephan Brunner, Olivier Sauter, Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Thibaut Vernay, Ben McMillan

Linearized operators describing inter-species and like-species collisions have been discretized and implemented in the gyrokinetic Particle-In-Cell (PIC) code ORB5 [S. Jolliet, Comp. Phys. Comm. 177, 409 ( 2007)] based on the delta-f approach. Simulation r ...

Iop Publishing Ltd, Dirac House, Temple Back, Bristol Bs1 6Be, England2010

Quasi-steady and steady states in global gyrokinetic particle-in-cell simulations

Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Thibaut Vernay, Ben McMillan

Collisionless delta-f gyrokinetic particle-in-cell simulations suffer from the entropy paradox, in which the entropy grows linearly in time while low-order moments are saturated. As a consequence, these simulations do not reach a steady state and are unsui ...

American Institute of Physics (AIP)2009

Influence of the parallel nonlinearity on zonal flows and heat transport in global gyrokinetic particle-in-cell simulations

Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Thibaut Vernay, Ben McMillan

In this paper, the influence of the parallel nonlinearity on zonal flows and heat transport in global particle-in-cell ion-temperature-gradient simulations is studied. Although this term is in theory orders of magnitude smaller than the others, several aut ...

American Institute of Physics (AIP)2009