Publications by Gergely Papp | EPFL Graph Search

Benign termination of runaway electron beams on ASDEX Upgrade and TCV

Basil Duval, Stefano Coda, Joan Decker, Umar Sheikh, Jean Arthur Cazabonne, Claudia Colandrea, Luke Simons, Gergely Papp, Bernhard Sieglin

This paper discusses the development of a benign termination scenario for runaway electron (RE) beams on ASDEX Upgrade and TCV. A systematic study revealed that a low electron density (n e) companion plasma was required to achieve a large MHD instability, ...

Iop Publishing Ltd2024

Full conversion from ohmic to runaway electron driven current via massive gas injection in the TCV tokamak

Patrick Blanchard, Basil Duval, Olivier Sauter, Stefano Coda, Benoît Labit, Joan Decker, Umar Sheikh, Cristian Galperti, Gergely Papp

Full conversion from ohmic to runaway electron (RE) driven current was observed in the tokamak a configuration variable (TCV) following massive injection of neon through a disruption mitigation valve into a low-density limited circular plasma. Following a ...

IOP Publishing Ltd2022

Physics of runaway electrons with shattered pellet injection at JET

Javier García Hernández, Cristian Sommariva, Gergely Papp

Runaway electrons (REs) created during tokamak disruptions pose a threat to the reliable operation of future larger machines. Experiments using shattered pellet injection (SPI) have been carried out at the JET tokamak to investigate ways to prevent their g ...

2022

Tomographic reconstruction of the runaway distribution function in TCV using multispectral synchrotron images

Basil Duval, Joan Decker, Umar Sheikh, Gergely Papp, Artur Perek

Synchrotron radiation observed in a quiescent Tokamak a Configuration Variable (TCV) runaway discharge is studied using filtered camera images targeting three distinct wavelength intervals. Through the tomographic simultaneous algebraic reconstruction tech ...

IOP Publishing Ltd2021

Disruption mitigation efficiency and scaling with thermal energy fraction on ASDEX Upgrade

Basil Duval, Umar Sheikh, Gergely Papp

Disruption mitigation remains a critical and unresolved issue for ITER. Measurement uncertainties preventing quantification of a system's efficacy remains a significant hurdle in producing and validating a viable disruption mitigation system. This study ad ...

IOP Publishing Ltd2020

Runaway electron synchrotron radiation in a vertically translated plasma

Basil Duval, Joan Decker, Umar Sheikh, Gergely Papp, Artur Perek

Synchrotron radiation observed from runaway electrons (REs) in tokamaks depends upon the position and size of the RE beam, the RE energy and pitch distributions, as well as the location of the observer. We show experimental synchrotron images of a vertical ...

IOP Publishing Ltd2020

Overview of physics studies on ASDEX Upgrade

Basil Duval, Timothy Goodman, Richard Pitts, Olivier Sauter, Stefano Coda, Alberto Bottino, Marco Wischmeier, Andrea Scarabosio, Hartmut Zohm, Laurie Porte, Yann Camenen, Thomas Binderup Jensen, Benoît Labit, Emiliano Fable, Alessandro Bortolon, Federico Alberto Alfredo Felici, Fang Liu, Dávid Wágner, Antoine Pierre Emmanuel Alexis Merle, Emanuele Poli, Nicola Vianello, Giovanni Tardini, Cristian Sommariva, Alessandro Pau, Otto Asunta, Haomin Sun, Xiao Wang, Gergely Papp, Bernhard Sieglin

The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance the physics base of ITER and DEMO. Here, the full tungsten wall is a key asset for extrapolating to future devices. The high overall heat ...

IOP Publishing Ltd2019

Deep neural networks for plasma tomography with applications to JET and COMPASS

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Duccio Testa, Emiliano Fable, Mikhail Maslov, Javier García Hernández, Federico Alberto Alfredo Felici, Daniele Brunetti, Dalziel Joseph Wilson, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Kenji Tanaka, Haomin Sun, Michele Marin, Yiming Li, Gergely Papp, Bernhard Sieglin

Convolutional neural networks (CNNs) have found applications in many image processing tasks, such as feature extraction, image classification, and object recognition. It has also been shown that the inverse of CNNs, so-called deconvolutional neural network ...

2019

Runaway electron beam stability and decay in COMPASS

Karin Söderström, Joan Decker, Gergely Papp

This paper presents two scenarios used for generation of a runaway electron (RE) beam in the COMPASS tokamak with a focus on the decay phase and control of the beam. The first scenario consists of massive gas injection of argon into the current ramp-up pha ...

IOP Publishing Ltd2019

Role of fast ion pressure in the isotope effect in JET L-mode plasmas

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Duccio Testa, Emiliano Fable, Mikhail Maslov, Javier García Hernández, Federico Alberto Alfredo Felici, Daniele Brunetti, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Kenji Tanaka, Haomin Sun, Michele Marin, Yiming Li, Gergely Papp, Bernhard Sieglin

This paper presents results of JET ITER-like wall L-mode experiments in hydrogen and deuterium (D) plasmas, dedicated to the study of the isotope dependence of ion heat transport by determination of the ion critical gradient and stiffness by varying the io ...

2019

Runaway electron modelling in the self-consistent core European Transport Simulator

Joan Decker, Gergely Papp

Relativistic runaway electrons are a major concern in tokamaks. Although significant theoretical development had been undertaken in recent decades, we still lack a self-consistent simulator that could simultaneously capture all aspects of this phenomenon. ...

IOP Publishing Ltd2019

Modification of the Alfven wave spectrum by pellet injection

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Ricardo Lima, Duccio Testa, Emiliano Fable, Mikhail Maslov, Javier García Hernández, Soo-Jin Moon, Federico Alberto Alfredo Felici, Daniele Brunetti, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Kenji Tanaka, Haomin Sun, Michele Marin, Yiming Li, Gergely Papp, Bernhard Sieglin

Alfven eigenmodes driven by energetic particles are routinely observed in tokamak plasmas. These modes consist of poloidal harmonics of shear Alfven waves coupled by inhomogeneity in the magnetic field. Further coupling is introduced by 3D inhomogeneities ...

2019

A Variable Structure Control Scheme Proposal for the Tokamak a Configuration Variable

Patrick Blanchard, 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, Duccio Testa, Benoît Labit, Rémy Jacquier, Paolo Ricci, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, 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, Federico Nespoli, Oulfa Chellaï, Anna Teplukhina, , , , , , , , , , , , , ,

Runaway electron beam control

Basil Duval, Stefano Coda, Diego Carnevale, Georgios Pappas, Joan Decker, Umar Sheikh, Cristian Galperti, Filippo Bagnato, Gergely Papp

Post-disruption runaway electron (RE) beams in tokamaks with large current can cause deep melting of the vessel and are one of the major concerns for ITER operations. Consequently, a considerable effort is provided by the scientific community in order to t ...

IOP PUBLISHING LTD2019

Ion cyclotron resonance heating scenarios for DEMO

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Duccio Testa, Emiliano Fable, Mikhail Maslov, Javier García Hernández, Federico Alberto Alfredo Felici, Daniele Brunetti, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Kenji Tanaka, Haomin Sun, Michele Marin, Yiming Li, Gergely Papp, Bernhard Sieglin

The present paper offers an overview of the potential of ion cyclotron resonance heating (ICRH) or radio frequency heating for the DEMO machine. It is found that various suitable heating schemes are available. Similar to ITER and in view of the limited ban ...

2019

Evolution of nitrogen concentration and ammonia production in N-2-seeded H-mode discharges at ASDEX Upgrade

Basil Duval, Timothy Goodman, Richard Pitts, Olivier Sauter, Stefano Coda, Alberto Bottino, Marco Wischmeier, Andrea Scarabosio, Hartmut Zohm, Laurie Porte, Yann Camenen, Thomas Binderup Jensen, Emiliano Fable, Federico Alberto Alfredo Felici, Dávid Wágner, Doohyun Kim, Antoine Pierre Emmanuel Alexis Merle, Emanuele Poli, Nicola Vianello, Giovanni Tardini, Donghyun Kim, Cristian Sommariva, Otto Asunta, Haomin Sun, Xiao Wang, Gergely Papp, Bernhard Sieglin

Ammonia formation was studied in a series of dedicated nitrogen seeded H-mode discharges at ASDEX Upgrade. The evolution of ammonia formation was investigated with a reference phase before the seeding, and a long, stable flat-top nitrogen-seeded phase. It ...

IOP Publishing Ltd2019

Self-consistent pedestal prediction for JET-ILW in preparation of the DT campaign

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Duccio Testa, Emiliano Fable, Mikhail Maslov, Javier García Hernández, Federico Alberto Alfredo Felici, Daniele Brunetti, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Paulo Giovane Paschoali Pereira Puglia, Eduardo José Lascas Neto, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Kenji Tanaka, Haomin Sun, Michele Marin, Yiming Li, Gergely Papp, Bernhard Sieglin

The self-consistent core-pedestal prediction model of a combination of EPED1 type pedestal prediction and a simple stiff core transport model is able to predict Type I ELMy (edge localized mode) pedestals of a large JET-ILW (ITER-like wall) database at the ...

2019

COREDIV numerical simulation of high neutron rate JET-ILW DD pulses in view of extension to JET-ILW DT experiments

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Martinus Gijs, Partha Dutta, Marco Wischmeier, Jan Horacek, Vlad Trifa, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Ricardo Lima, Duccio Testa, Emiliano Fable, Sun Hee Kim, Mikhail Maslov, Javier García Hernández, Soo-Jin Moon, Federico Alberto Alfredo Felici, José Pedro Rebelo Ferreira Marques, Julio Rodriguez, Pedro Camilo de Oliveira e Silva, Daniel Scott Alessi, Daniele Brunetti, Jonnathan Cesar Hidalgo Acosta, Ana Francisca Leal Silva Soares, Dalziel Joseph Wilson, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Alberto Hernando de Castro, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Bruno Emanuel Ferreira De Sousa Correia, Li Shuai, , , , , , , , , , , , , , ,

Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Martinus Gijs, Partha Dutta, Marco Wischmeier, Jan Horacek, Vlad Trifa, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Ricardo Lima, Duccio Testa, Emiliano Fable, Karin Söderström, Sun Hee Kim, Mikhail Maslov, Javier García Hernández, Soo-Jin Moon, Federico Alberto Alfredo Felici, José Pedro Rebelo Ferreira Marques, Julio Rodriguez, Pedro Camilo de Oliveira e Silva, Daniel Scott Alessi, Daniele Brunetti, Jonnathan Cesar Hidalgo Acosta, Ana Francisca Leal Silva Soares, Dalziel Joseph Wilson, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Alberto Hernando de Castro, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Bruno Emanuel Ferreira De Sousa Correia, , , , , , , , , , , , , , , ,

Interpretative and predictive modelling of Joint European Torus collisionality scans

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Richard Pitts, Olivier Sauter, Henri Weisen, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Francesca Maria Poli, Duccio Testa, Emiliano Fable, Mikhail Maslov, Javier García Hernández, Federico Alberto Alfredo Felici, Daniele Brunetti, Antoine Pierre Emmanuel Alexis Merle, Federico Nespoli, Anna Teplukhina, Leonardo Pigatto, Hamish William Patten, Alberto Mariani, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Kenji Tanaka, Haomin Sun, Michele Marin, Yiming Li, Gergely Papp, Bernhard Sieglin

Transport modelling of Joint European Torus (JET) dimensionless collisionality scaling experiments in various operational scenarios is presented. Interpretative simulations at a fixed radial position are combined with predictive JETTO simulations of temper ...

2019