Publications de Madhusudan Raghunathan

Implementation of multi-component Zhdanov closure in SOLEDGE3X

Davide Galassi, Madhusudan Raghunathan, Eric Serre

The multi-component fluid closure derived by Zhdanov (2002 Transport Processes in Multicomponent Plasma (London: Taylor and Francis)) is implemented in the fluid code SOLEDGE3X-EIRENE to deal with arbitrary edge plasma composition. The closure assumes no d ...

2022

Stellarator nonlinearly saturated periodicity-breaking ideal magnetohydrodynamic equilibrium states

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

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

Effects of 3D Ideal MHD Equilibrium Geometry on Neoclassical Properties in Tokamaks: Exploring Bootstrap Current and Impurity Accumulation

Madhusudan Raghunathan

This thesis concentrates on investigating the presence of 3D ideal MHD instabilities, particularly a saturated 1/1 ideal internal kink, on neoclassical phenomena such as the bootstrap current and heavy impurity transport. The MHD equilibria are generated u ...

EPFL2018

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

Jonathan Graves, Wilfred Anthony Cooper, 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

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

Olivier Sauter, Basil Duval, Jonathan Graves, Wilfred Anthony Cooper, Holger Reimerdes, Laurie Porte, Trach-Minh Tran, David Pfefferlé, Jonathan Marc Philippe Faustin, 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

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

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

Simulation of bootstrap current in 2D and 3D ideal magnetic fields in tokamaks

Olivier Sauter, Jonathan Graves, Wilfred Anthony Cooper, Madhusudan Raghunathan, Michael Pedro

We aim to simulate the bootstrap current for a MAST-like spherical tokamak using two approaches for magnetic equilibria including externally caused 3D effects such as resonant magnetic perturbations (RMPs), the effect of toroidal ripple, and intrinsic 3D e ...

Iop Publishing Ltd2016

Free boundary equilibrium in 3D tokamaks with toroidal rotation

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