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David Pfefferlé

Cette personne n’est plus à l’EPFL

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Publications associées (157)

Higher order Larmor radius corrections to guiding-centre equations and application to fast ion equilibrium distributions

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Samuel Lanthaler

An improved set of guiding-centre equations, expanded to one order higher in Larmor radius than usually written for guiding-centre codes, are derived for curvilinear flux coordinates and implemented into the orbit following code VENUS-LEVIS. Aside from gre ...

Iop Publishing Ltd2017

Heavy Impurity Confinement in Hybrid Operation Scenario Plasmas with a Rotating 1/1 Continuous Mode

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Madhusudan Raghunathan

In future tokamaks like ITER with tungsten walls, it is imperative to control tungsten accumulation in the core of operational plasmas, especially since tungsten accumulation can lead to radiative collapse and disruption. We investigate the behaviour of tu ...

IOP Science2017

Overview of the JET results in support to ITER

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Yves Martin, Richard Pitts, Olivier Sauter, Henri Weisen, Stefano Coda, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Duccio Testa, Mikhail Maslov, Javier García Hernández, David Pfefferlé, Dalziel Joseph Wilson, Jonathan Marc Philippe Faustin, Federico Nespoli, Hamish William Patten, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Liang Yao, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Bernhard Sieglin

The 2014-2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its ins ...

IOP Publishing Ltd2017

Effects of magnetic ripple on 3D equilibrium and alpha particle confinement in the European DEMO

Wilfred Anthony Cooper, Ambrogio Fasoli, Jonathan Graves, David Pfefferlé

An assessment of alpha particle confinement is performed in the European DEMO reference design. 3D MHD equilibria with nested flux-surfaces and single magnetic axis are obtained with the VMEC free-boundary code, thereby including the plasma response to the ...

IOP Science2016

ICRH induced particle losses in Wendelstein 7-X

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Jonathan Marc Philippe Faustin

Fast ions in W7-X will be produced either by neutral beam injection (NBI) or by ion-cyclotron resonant heating (ICRH). The latter presents the advantage of depositing power locally and does not suffer from core accessibility issues (Drevlak et al 2014 Nucl ...

Plasma Physics and Controlled Fusion2016

Fast particle loss channels in Wendelstein 7-X

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Jonathan Marc Philippe Faustin

One of the main goals of Wendelstein 7-X (W7-X) is to demonstrate the fast particle confinement properties of the quasi-isodynamic stellarator concept. Fast particle populations will be produced either by Neutral Beam Injection (NBI) or by minority Ion Cyc ...

Nuclear Fusion2016

Saturated ideak kink/peeling formations described as three-dimensional magnetohydrodynamic tokamak equilibrium states

Wilfred Anthony Cooper, Basil Duval, Olivier Sauter, Trach-Minh Tran, Holger Reimerdes, Laurie Porte, Jonathan Graves, David Pfefferlé, Daniele Brunetti, Andreas Kleiner, Jonathan Marc Philippe Faustin, Madhusudan Raghunathan, Hamish William Patten

Free boundary magnetohydrodynamic equilibrium states with spontaneous three dimensional deformations of the plasma-vacuum interface are computed for the first time. The structures obtained have the appearance of saturated ideal external kink/peeling modes. ...

American Institute of Physics (AIP)2016

Modelling of ICRF fast ion generation in 2D and 3D plasma configurations

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Jonathan Marc Philippe Faustin

2016

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

Free boundary equilibrium in 3D tokamaks with toroidal rotation

Wilfred Anthony Cooper, Olivier Sauter, Minh Tâm Tran, Jonathan Graves, David Pfefferlé, Daniele Brunetti, Jonathan Marc Philippe Faustin, Madhusudan Raghunathan

The three-dimensional VMEC equilibrium solver has been adapted to numerically investigate the approximate toroidal rotation model we have derived. We concentrate our applications on the simulation of JET snakes and MAST long-lived modes under free boundary ...

IOP Publishing Ltd2015

Energetic ion dynamics and confinement in 3D saturated MHD configurations

David Pfefferlé

In the following theoretical and numerically oriented work, a number of findings have been assembled. The newly devised VENUS-LEVIS code, designed to accurately solve the motion of energetic particles in the presence of 3D magnetic fields, relies on a non- ...

EPFL2015

NBI fast ion confinement in the helical core of MAST hybrid-like plasmas

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Cyril Misev

Energetic ions are found to be transported strongly from the core of MAST hybrid-like plasmas during long-lived mode (LLM) magnetohydrodynamic activity. The resulting impact on the neutral beam ion deposition and concurrent current drive is modelled usin ...

IOP Publishing Ltd2014

VENUS-LEVIS and its spline-Fourier interpolation of 3D toroidal magnetic field representation for guiding-centre and full-orbit simulations of charged energetic particles

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Cyril Misev

Curvilinear guiding-centre drift and full-orbit equations of motion are presented as implemented in the code{VENUS-LEVIS} code. A dedicated interpolation scheme based on Fourier reconstruction in the toroidal and poloidal direction and cubic spline in the ...

Elsevier2014

Impact of RMP magnetic field simulation models on fast ion losses

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé, Cyril Misev

Two opposing approaches to include resonant magnetic perturbations (RMPs) in fast ion simulations are compared, one where the vacuum field caused by the RMP current coils is added to the axisymmetric MHD equilibrium, the other where the MHD equilibrium inc ...

International Atomic Energy Agency2014

Bifurcated Helical Core Equilibrium States in Tokamaks

Wilfred Anthony Cooper, Basil Duval, Antoine Pochelon, Olivier Sauter, Trach-Minh Tran, Holger Reimerdes, Stefano Coda, Jonathan Graves, Benoît Labit, David Pfefferlé, Federico David Halpern, Daniele Brunetti

Tokamaks with weak to moderate reversed central shear in which the minimum inverse rotational transform (safety factor) qmin is in the neighbourhood of unity can trigger bifurcated magnetohydrodynamic equilibrium states, one of which is similar to a satura ...

IOP Publishing Ltd2013

Exploitation of a general-coordinate guiding centre code for the redistribution of fast ions in deformed hybrid tokamak equilibria

Wilfred Anthony Cooper, Jonathan Graves, David Pfefferlé

Self-consistent fast ion distributions are usually obtained using a code that solves the guiding-centre equations, with an appropriate fast ion source (e.g. NBI pinis) and sink (e.g. collision operators). Straight field-line coordinate systems, such as Boo ...

Iop Publishing Ltd2012

Bifurcated Helical Core Equilibrium States in Tokamaks

Wilfred Anthony Cooper, Basil Duval, Antoine Pochelon, Olivier Sauter, Holger Reimerdes, Stefano Coda, Jonathan Rossel, Jonathan Graves, Benoît Labit, David Pfefferlé, Mattia Albergante, Federico David Halpern, Daniele Brunetti

Tokamaks with weak to moderate reversed central shear in which the minimum rotational transform

q_{min}

is in the neighbourhood of unity can trigger bifurcated MagnetoHydrodynamic (MHD) equilibrium states, one of which is similar to a saturated ideal ...

2012

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