The x-ray transitions in Cu- and Ni-like tungsten ions in the 5.19-5.26 angstrom wavelength range that are relevant as a high-temperature tokamak diagnostic, in particular for JET in the ITER-like wall configuration, have been studied. Tungsten spectra wer ...

2018

Impact of electron-scale turbulence and multi-scale interactions in the JET tokamak

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

Experimental observations in JET tokamak plasmas and gyrokinetic simulations point to an important role, for electron heat transport, of electron-scale instabilities and of their interaction with ion-scale instabilities. Since these effects are maximized f ...

IOP Publishing Ltd2018

Application of the VUV and the soft x-ray systems on JET for the study of intrinsic impurity behavior in neon seeded hybrid discharges

Jonathan Graves

This paper reports on impurity behavior in a set of hybrid discharges with Ne seeding-one of the techniques considered to reduce the power load on reactor walls. A series of experiments carried out with light gas injection on JET with the ITER-Like-Wall (I ...

2018

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

Sliding Surface Based Schemes for the Tokamak a Configuration Variable

Patrick Blanchard, Stefano Alberti, Basil Duval, Ambrogio Fasoli, Timothy Goodman, Xavier Llobet, Yves Martin, Jean-Marc Moret, Olivier Sauter, Minh Quang Tran, Henri Weisen, Ivo Furno, Holger Reimerdes, Jean-Philippe Hogge, Stefano Coda, Christian Schlatter, Marco Wischmeier, Jan Horacek, Alexander Karpushov, Laurie Porte, Yanis Andrebe, Yann Camenen, Jonathan Graves, Bernard Schneider, Duccio Testa, Benoît Labit, Rémy Jacquier, Paolo Ricci, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Miguel Filipe Silva Füglister, Fabio Riva, Wouter Vijvers, Josef Kamleitner, Hoang Bao Le, Zhouji Huang, Himank Anand, Falk Hans Braunmüller, Joyeeta Sinha, Claudio Marini, Antoine Pierre Emmanuel Alexis Merle, , , , , , , , , , , , , , , , , , ,

Modelling of JET hybrid plasmas with emphasis on performance of combined ICRF and NBI heating

Jonathan Graves, Javier García Hernández

During the 2015-2016 JET campaigns, many efforts have been devoted to the exploration of high-performance plasma scenarios envisaged for DT operation in JET. In this paper, we review various key recent hybrid discharges and model the combined ICRF+NBI heat ...

IOP Publishing Ltd2018

Nonlinear dynamic analysis of D-alpha signals for type I edge localized modes characterization on JET with a carbon wall

Gilles Arnoux, Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Yves Martin, Richard Pitts, Olivier Sauter, Henri Weisen, Robin Humphry-Baker, Stefano Coda, Martinus Gijs, Partha Dutta, Marco Wischmeier, Jan Horacek, Andrea Scarabosio, Vlad Trifa, Jonathan Graves, Duccio Testa, Miguel Fernández Ruiz, Sun Hee Kim, Mikhail Maslov, Javier García Hernández, David Pfefferlé, José Pedro Rebelo Ferreira Marques, Pedro Camilo de Oliveira e Silva, Daniel Filipe Dos Santos Alves Jana, Rebecca Hill, Jonnathan Cesar Hidalgo Acosta, Dalziel Joseph Wilson, Pierre-Thomas Paul Brun, Jonathan Marc Philippe Faustin, Federico Nespoli, Joan Decker, Cristian Galperti, Bruno Emanuel Ferreira De Sousa Correia, Antonio José Pereira de Figueiredo, Liang Yao, Thomas Jean F Bauwens, Otto Asunta,

Analytic study on low-n external ideal infernal modes in tokamaks with large edge pressure gradients

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

The problem of pressure driven infernal type perturbations near the plasma edge is addressed analytically for a circular limited tokamak configuration which presents an edge flattened safety factor. The plasma is separated from a metallic wall, either idea ...

Cambridge University Press2018

Ion cyclotron resonance heating for tungsten control in various JET H-mode scenarios

Jonathan Graves, Javier García Hernández

Ion cyclotron resonance heating (ICRH) in the hydrogen minority scheme provides central ion heating and acts favorably on the core tungsten transport. Full wave modeling shows that, at medium power level (4MW), after collisional redistribution, the ratio o ...

2017

A novel approach to ion-ion Langevin self-collisions in particle-in-cell modules applied to hybrid MHD codes

Jonathan Graves

In order to have a better closure for magnetohydrodynamic (MHD) equations, a common approach is to obtain the ion fluid pressure tensor by directly computing the moments of an ion distribution function, obtained by a Particle-in-cell (PIC) solver of the V ...

IOP Publishing2017

Modelling of advanced three-ion ICRF heating and fast ion generation scheme for tokamaks and stellarators

Wilfred Anthony Cooper, Laurent Villard, Jonathan Graves, David Pfefferlé, Jonathan Marc Philippe Faustin, Samuel Lanthaler

Absorption of ion-cyclotron range of frequencies waves at the fundamental resonance is an efficient source of plasma heating and fast ion generation in tokamaks and stellarators. This heating method is planned to be exploited as a fast ion source in the We ...

2017

The DEMO wall load challenge

Ambrogio Fasoli, Jan Horacek, Hartmut Zohm, Jonathan Graves, David Pfefferlé, Samuel Lanthaler, Bernhard Sieglin

For several reasons the challenge to keep the loads to the first wall within engineering limits is substantially higher in DEMO compared to ITER. Therefore the pre-conceptual design development for DEMO that is currently ongoing in Europe needs to be based ...

IOP Publishing Ltd2017

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

Page 10 of 17

Liang Yao

Arnout Lodewijk M Beckers

This work aims at establishing the parameter space for the existence of geodesic acoustic modes (GAMs) on JET as well as investigating their driving and damping mechanisms predicted by different theoretical models. This was achieved using an experimental d ...

2018

Samuel Lanthaler

Liang Yao

Arnout Lodewijk M Beckers

Reliable algorithms for disruption avoidance and prediction are foreseen to play a fundamental role in the JET control system for the successful operation of the machine in the upcoming deuterium-tritium campaigns. The integration of such algorithms is exp ...

2018

Samuel Lanthaler

Liang Yao

Arnout Lodewijk M Beckers

This paper presents the first application to real JET data of the new equilibrium code NICE which enables the consistent resolution of the inverse equilibrium reconstruction problem in the framework of non-linear free-boundary equilibrium coupled to the St ...

IOP Publishing Ltd2018

Samuel Lanthaler

Liang Yao

Arnout Lodewijk M Beckers

2018

Arnout Lodewijk M Beckers

2018

Pedro Andres Molina Cabrera

Matteo Fontana

Umar Sheikh

Cristian Galperti

Kevin Henricus Annemarie Verhaegh

Fusion power may be seen as the energy of the future in the sense that it composes a potentially clean, cheap and unlimited power source that would reduce the worldwide dependency on non-renewable energies. Nevertheless, while nowadays the fusion reaction ...

IEEE2018

Bernhard Sieglin

In this paper, the dynamic characteristics of type-I ELM time-series from the JET tokamak, the world's largest magnetic confinement plasma physics experiment, have been investigated. The dynamic analysis has been focused on the detection of nonlinear struc ...

2018