Recherche

Afficher tous les résultats pour

Accueil

Personne

Wilfred Anthony Cooper

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (112)

Three-dimensional distortions of the tokamak plasma boundary: boundary displacements in the presence of resonant magnetic perturbations

Wilfred Anthony Cooper

The three-dimensional plasma boundary displacements induced by applied non-axisymmetric magnetic perturbations have been measured in ASDEX Upgrade, DIII-D, JET, MAST and NSTX. The displacements arising from applied resonant magnetic perturbations (RMPs) ar ...

IOP Publishing Ltd2014

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

Three-dimensional distortions of the tokamak plasma boundary: boundary displacements in the presence of saturated MHD instabilities

Wilfred Anthony Cooper, Jonathan Graves, Daniele Brunetti

The three-dimensional plasma boundary displacement induced by long-lasting core magnetohydrodynamic (MHD) instabilities has been measured in JET, MAST and NSTX. Only saturated instabilities are considered here since transient rapidly growing modes which de ...

IOP Publishing Ltd2014

Self-consistent Simulations of ICRH with the Background Equilibrium in Tokamaks and Stellarators

Wilfred Anthony Cooper, Martin Jucker, Jonathan Graves

The SCENIC code package has been developed to integrate self-consistently an anisotropic pressure magnetohydrodynamic equilibrium state with power absorption from Ion Cyclotron Resonance Heating and with a guiding center particle distribution function for ...

American Nuclear Society2014

Fast growing resistive two fluid instabilities in hybrid-like tokamak configuration

Wilfred Anthony Cooper, Jonathan Graves, Daniele Brunetti

An analytic derivation of the dispersion relation for resistive instabilities in a low-shear tokamak configuration is presented. The resistive infernal mode model (Charlton et al 1989 Phys. Fluids B 1 798) is generalized to include plasma diamagnetism, sub ...

Institute of Physics2014

Ideal saturated MHD helical structures in axisymmetric hybrid plasmas

Wilfred Anthony Cooper, Jonathan Graves, Daniele Brunetti

Kinked saturated m = 1 helical structures are frequently observed in tokamak hybrid plasmas and in reversed field pinches (RFP). These modes occur when an extremum in the safety factor is close to, but necessarily resonant with, a low order rational (typic ...

International Atomic Energy Agency2014

Magnetohydrodynamic helical structures in nominally axisymmetric low-shear tokamak plasmas

Wilfred Anthony Cooper, Antoine Pochelon, Olivier Sauter, Holger Reimerdes, Jonathan Graves, Federico David Halpern, Daniele Brunetti

The primary goal of hybrid scenarios in tokamaks is to enable high performance operation with large plasma currents whilst avoiding MHD instabilities. However, if a local minimum in the safety factor is allowed to approach unity, the energy required to ove ...

Iop Publishing Ltd2013

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

Extension of operation regimes and investigation of three-dimensional currentless plasmas in the Large Helical Device

Wilfred Anthony Cooper, Terunobu Akiyama, Kenji Tanaka

The progress of physical understanding as well as parameter improvement of net-current-free helical plasma is reported for the Large Helical Device since the last Fusion Energy Conference in Daejeon in 2010. The second low-energy neutral beam line was inst ...

IOP Publishing Ltd2013

Overview of the RFX-mod fusion science programme

Wilfred Anthony Cooper, Ambrogio Fasoli, Ivo Furno, Christian Gabriel Theiler, Fabio Avino, Elena Gaio, Nicola Vianello, Alberto Ferro

This paper reports the highlights of the RFX-mod fusion science programme since the last 2010 IAEA Fusion Energy Conference. The RFX-mod fusion science programme focused on two main goals: exploring the fusion potential of the reversed field pinch (RFP) ma ...

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

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

Ideal MHD spectrum calculations for the ARIES-CS configuration

Wilfred Anthony Cooper

Ideal MHD stability calculations for the ARIES compact stellarator (ARIES-CS) reactor design (Najmabadi et al 2008 Fusion Sci. Technol. 54 655) show a spectrum of instabilities. The ARIES design considered is a three field-period stellarator with engineeri ...

IOP Publishing Ltd2011

Helical core tokamak MHD equilibrium states

Wilfred Anthony Cooper, Basil Duval, Antoine Pochelon, Olivier Sauter, Holger Reimerdes, Stefano Coda, Jonathan Rossel, Jonathan Graves, Benoît Labit, Mattia Albergante

Bifurcated magnetohydrodynamic tokamak equilibrium states with axisymmetric or helical core structure are computed. When a peaked pressure profile is chosen, the helical core structures appear like the {em snakes} that are observed in the JET tokamak. They ...

Caroline Wilkinson2011

Numerical modelling of electromagnetic turbulent transport of energetic ions in burning plasmas

Wilfred Anthony Cooper, Ambrogio Fasoli, Martin Jucker, Jonathan Graves, Xavier Lapillonne, Mattia Albergante

We investigate the redistribution of the neutral beam driven current in the presence of small scale turbulence in the ITER steady-state scenario. Gyrokinetic simulations show that anomalous transport of beam ions can be larger than collisional estimates. T ...

Institute of Physics2011

Convolution and iterative methods applied to low frequency waves in 3D configurations

Stephan Brunner, Wilfred Anthony Cooper, Laurent Villard, Nicolas Mellet

Kinetic effects have been implemented in the three-dimensional full-wave code LEMan. These allow modeling Landau damping as well as the Kinetic Alfvén Wave (KAW). Special attention has been taken on the exact computation of the parallel wave vector as it c ...

Elsevier2011

Ion cyclotron resonance heating with consistent finite orbit widths and anisotropic equilibria

Wilfred Anthony Cooper, Martin Jucker, Jonathan Graves

Minority ion cyclotron resonance heating is studied using the self-consistent numerical model SCENIC. This model includes 3D geometries with full shaping and anisotropic pressure effects, warm contributions to the dielectric tensor and full orbit effects. ...

Institute of Physics2011

JET Snake Magnetohydrodynamic Equilibria

Wilfred Anthony Cooper, Olivier Sauter, Jonathan Graves

Magnetohydrodynamic (MHD) equilibrium states with a three-dimensional helical core that display the characteristics of a saturated ideal internal kink mode are computed to model snake structures that have been observed in the JET tokamak [A.~Weller et al. ...

IOP Publishing Ltd2011

Full-field drift Hamiltonian particle orbits in axisymmetric tokamak geometry

Wilfred Anthony Cooper, Jonathan Graves

A Hamiltonian/Lagrangian theory to describe guiding center orbit drift motion that is canonical in Boozer magnetic coordinates is developed to include full electrostatic and electromagnetic perturbed fields in axisymmetric tokamak geometry. Furthermore, th ...

American Institute of Physics (AIP)2011

Page 3 sur 6