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Ben McMillan

Cette personne n’est plus à l’EPFL

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Publications associées (53)

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

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

Diamagnetic drift stabilized ballooning modes in a 3D heliotron

Wilfred Anthony Cooper, Ben McMillan

An analysis of kinetic ballooning modes is presented, ray trajectories for the inward shifted Large Helical Device configuration at modest $$ and with an anisotropic pressure profile due to the hot particles are evaluated and an estimate of the margi ...

IOP Publishing2012

Predictions on heat transport and plasma rotation from global gyrokinetic simulations

Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Ben McMillan

Flux-driven global gyrokinetic codes are now mature enough to make predictions in terms of turbulence and transport in tokamak plasmas. Some of the recent breakthroughs of three such codes, namely GYSELA, ORB5 and XGC1, are reported and compared wherever a ...

IOP Publishing Ltd2011

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

Flux- and gradient-driven global gyrokinetic simulation of tokamak turbulence

Stephan Brunner, Olivier Sauter, Laurent Villard, Xavier Lapillonne, Ben McMillan

The Eulerian gyrokinetic turbulence code GENE has recently been extended to a full torus code. Moreover, it now provides Krook-type sources for gradient-driven simulations where the profiles are maintained on average as well as localized heat sources for a ...

2011

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

Nonlinear quasisteady state benchmark of global gyrokinetic codes

Stephan Brunner, Laurent Villard, Xavier Lapillonne, Ben McMillan

Two global gyrokinetic codes are benchmarked against each other by comparing simulation results in the case of ion temperature gradient driven turbulence, in the adiabatic electron response limit The two codes are the Eulerian code GENE and the Lagrangian ...

American Institute of Physics2010

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

System size effects on gyrokinetic turbulence

Laurent Villard, Alberto Bottino, Sébastien Jolliet, Xavier Lapillonne, Ben McMillan

The scaling of turbulence-driven heat transport with system size in magnetically confined plasmas is reexamined using first-principles based numerical simulations. Two very different numerical methods are applied to this problem, in order to resolve a long ...

The American Physical Society2010

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

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

Avalanche-like bursts in global gyrokinetic simulations

Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Ben McMillan

Highly variable flux surface averaged heat fluxes are resolved in gyrokinetic simulations of ion temperature gradient (ITG) turbulence, even in large systems. Radially propagating fronts or avalanches are also seen. Their propagation lengths in gyroradii a ...

American Institute of Physics (AIP)2009

Rapid Fourier space solution of linear partial differential equations in toroidal magnetic confinement geometries

Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Ben McMillan

Fluctuating quantities in magnetic confinement geometries often inherit a strong anisotropy along the field lines. One technique for describing these structures is the use of a certain set of Fourier components on the tori of nested flux surfaces. We descr ...

Elsevier2009

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

The role of plasma elongation on turbulent transport in magnetically confined plasmas

Trach-Minh Tran, Laurent Villard, Alberto Bottino, Sébastien Jolliet, Paolo Angelino, Ben McMillan

The theoretical study of plasma turbulence is of central importance to fusion research. Experimental evidence indicates that the confinement time results mainly from the turbulent transport of energy, the magnitude of which depends on the turbulent state r ...

American Physical Society2009

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

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