Publications de Wilfred Anthony Cooper

Understanding JET-C quiescent phases with edge harmonic magnetohydrodynamic activity and comparison with behaviour under ITER-like wall conditioning

Wilfred Anthony Cooper, Jonathan Graves, Daniele Brunetti, Alberto Mariani, Andreas Kleiner, Guillermo Bustos Ramirez

An analysis of edge localised mode-free (quiescent) H-mode discharges exhibiting edge harmonic magnetoydrodynamic activity in the JET-carbon wall machine is presented. It is observed that the otherwise quiescent pulses with multiple-n harmonic oscillations ...

IOP Publishing Ltd2022

DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy

Olivier Sauter, Stefano Coda, Wilfred Anthony Cooper

DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with funda ...

IOP Publishing Ltd2022

ICRF modelling in 2D and 3D magnetic configurations using a hot plasma model

Wilfred Anthony Cooper, Jonathan Graves, Mike Machielsen

The generation of energetic trapped ions is important for experiments investigating their confinement in 3D magnetic fields, for plasma heating, for studies into unwanted drive of instabilities, and improved transport regimes. An effective way to generate ...

2021

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

Identification of an Optimized Heating and Fast Ion Generation Scheme for the Wendelstein 7-X Stellarator

Jonathan Graves, Wilfred Anthony Cooper, David Pfefferlé, Hamish William Patten

A Doppler shifted resonance minority species ion cyclotron range of frequency (ICRF) scheme for heating neutral beam ions has been identified and optimized for theWendelstein 7-X stellarator. Compared with more conventional methods, the synergetic scheme i ...

2020

Anisotropy and shaping effects on the stability boundaries of infernal ideal MHD modes in tokamak hybrid plasmas

Wilfred Anthony Cooper, Jonathan Graves, Daniele Brunetti

Anisotropy and some limiting toroidal flow effects on the stability of nearly resonant ideal magnetohydrodynamic modes in hybrid shaped tokamak plasmas are investigated within the ideal MHD infernal mode framework. Such effects are found to alter the plasm ...

2020

DIII-D research towards establishing the scientific basis for future fusion reactors

Olivier Sauter, Wilfred Anthony Cooper, Lorenzo Anton-Louis Talà, Terunobu Akiyama, Mario Ludovico Podesta, Dongbin Zhao, Zhixian Yan, Jeffrey Huang, Xin Yang, Richard Pitts

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary ...

IOP Publishing Ltd2019

Helical equilibrium magnetohydrodynamic flow effects on the stability properties of low-n ideal external-infernal modes in weak shear tokamak configurations

Wilfred Anthony Cooper, Jonathan Graves, Patrycja Nowak-Sliwinska, Daniele Brunetti, Alberto Mariani

The impact of equilibrium helical flows on the stability properties of low shear tokamak plasmas is assessed. The corrections due to such helical flow to the equilibrium profiles (mass density, pressure, Shafranov shift, magnetic fluxes) are computed by mi ...

IOP PUBLISHING LTD2019

Guiding-centre theory for kinetic-magnetohydrodynamic modes in strongly flowing plasmas

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

A kinetic-magnetohydrodynamic model with kinetic pressure closure is derived from a consistent guiding-centre framework. Higher-order (gyroviscous) corrections to the pressure tensor are derived in complex geometry from a reduced kinetic equation. The prop ...

IOP PUBLISHING LTD2019

Excitation Mechanism of Low-n Edge Harmonic Oscillations in Edge Localized Mode-Free, High Performance, Tokamak Plasmas

Jonathan Graves, Wilfred Anthony Cooper, Daniele Brunetti, Alberto Mariani

2019