Publications by Andreas Kleiner

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, Andreas Kleiner, Alberto Mariani, 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

Non-linear modelling of saturated internal and external MHD instabilities in tokamaks

Andreas Kleiner

Macroscopic instabilities and their unfavourable effects on plasma confinement pose a central challenge for the development of reactor relevant tokamak scenarios. Some promising operation scenarios feature extended regions of low magnetic shear. These are ...

EPFL2019

Current and pressure gradient triggering and nonlinear saturation of low-n edge harmonic oscillations in tokamaks

Wilfred Anthony Cooper, Jonathan Graves, Daniele Brunetti, Andreas Kleiner, Antoine Pierre Emmanuel Alexis Merle

Non-axisymmetric free-boundary equilibrium computations are shown to represent nonlinearly saturated external kink modes and external kink-like sidebands coupled to pressure-driven infernal modes. In this study of edge harmonic oscillations associated with ...

IOP PUBLISHING LTD2019

Free boundary 3D ideal MHD equilibrium calculations for non-linearly saturated current driven external kink modes in tokamaks

Wilfred Anthony Cooper, Jonathan Graves, Andreas Kleiner

IOP Publishing Ltd2018

Stellarator nonlinearly saturated periodicity-breaking ideal magnetohydrodynamic equilibrium states

Wilfred Anthony Cooper, Jonathan Graves, Andreas Kleiner, Jonathan Marc Philippe Faustin, Madhusudan Raghunathan, Hamish William Patten, Samuel Lanthaler

The relaxation of the constraint of periodicity imposed by the external confining magnetic field coils in a nominally 4-field period Helias Advanced Stellarator configuration produces weak periodicity-breaking deformations of the plasma. The corrugations a ...

IOP Publishing Ltd2018

Neoclassical tearing mode seeding by coupling with infernal modes in low-shear tokamaks

Wilfred Anthony Cooper, Jonathan Graves, Federico David Halpern, Daniele Brunetti, Andreas Kleiner

A numerical and an analytical study of the triggering of resistive MHD modes in tokamak plasmas with low magnetic shear core is presented. Flat q profiles give rise to fast growing pressure driven MHD modes, such as infernal modes. It has been shown that i ...

IOP Publishing Ltd2016

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

Three-dimensional magnetohydrodynamic equilibrium of quiescent H-modes in tokamak systems

Wilfred Anthony Cooper, Basil Duval, Olivier Sauter, Trach-Minh Tran, Jonathan Graves, Andreas Kleiner, Jonathan Marc Philippe Faustin, Madhusudan Raghunathan, Hamish William Patten, Samuel Lanthaler

Three dimensional free boundary magnetohydrodynamic equilibria that recover saturated ideal kink/peeling structures are obtained numerically. Simulations that model the JET tokamak at fixed = 1.7% with a large edge bootstrap current that flattens t ...

IOP Publishing2016