Publications de Dahye Choi | EPFL Graph Search

Effect of energetic ions on edge-localized modes in tokamak plasmas

Olivier Sauter, Stefano Coda, Timothy Goodman, Jean-Marc Moret, Duccio Testa, Patrick Blanchard, Holger Reimerdes, Benoît Labit, Christian Gabriel Theiler, Federico Alberto Alfredo Felici

The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is the high-confinement mode. In this regime, however, periodic relaxations of the plasma edge can occur. These edge-localized modes pose a ...

2025

Overview of the TCV tokamak experimental programme

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Stefano Alberti, Ivo Furno, Duccio Testa

The tokamak a configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its c ...

IOP Publishing Ltd2022

Experimental analysis of suprathermal electrons generated by electron cyclotron waves in tokamak plasmas

Dahye Choi

This thesis focuses on the physics of suprathermal electrons generated by electron cyclotron (EC) waves in tokamak plasmas, which play an important role in the physics of current drive and energetic particle-driven instabilities. The suprathermal electron ...

EPFL2020

Study of suprathermal electron dynamics during electron cyclotron current drive using hard x-ray measurements in the TCV tokamak

Stefano Coda, Joan Decker, Jean Arthur Cazabonne, Dahye Choi

Suprathermal electron dynamics in real and momentum spaces plays an important role in the physics of electron cyclotron current drive (ECCD), in particular for predicting the wave driven current. In the TCV tokamak, a hard x-ray spectroscopy system equippe ...

2020

Modeling of the response function of CdTe detectors for a hard X-ray synthetic diagnostic

Stefano Coda, Joan Decker, Dahye Choi

The response function of CdTe detectors used in a hard X-ray spectrometer system (HXRS) on the TCV tokamak fusion experiment is modeled based on the measured energy spectra from multiple gamma-ray sources. The response function consists of an asymmetric Ga ...

2020

Suprathermal electron driven fishbone instability in the TCV tokamak

Stefano Coda, Jonathan Graves, Laurie Porte, Antoine Pierre Emmanuel Alexis Merle, Joan Decker, Dahye Choi, Arsène Stéphane Tema Biwole

Observations of fishbone oscillations driven by energetic electrons have been reported in several tokamaks, but experimental evidence of the interaction between electrons and the mode has remained limited. In the TCV tokamak, a state-of-the-art multi-chann ...

2019

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

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Timothy Goodman, Jonathan Graves, Yves Martin, Jean-Marc Moret, Ivo Furno, Duccio Testa

Fusion power is the most significant prospects in the long-term future of energy in the sense that it composes a potentially clean, cheap, and unlimited power source that would substitute the widespread traditional nonrenewable energies, reducing the geogr ...

2019

ELM-induced cold pulse propagation in ASDEX Upgrade

Olivier Sauter, Basil Duval, Stefano Coda, Timothy Goodman, Yves Martin, Jean-Marc Moret, Duccio Testa, Patrick Blanchard, Holger Reimerdes, Benoît Labit

In ASDEX Upgrade, the propagation of cold pulses induced by type-I edge localized modes (ELMs) is studied using electron cyclotron emission measurements, in a dataset of plasmas with moderate triangularity. It is found that the edge safety factor or the pl ...

2019

A locked mode indicator for disruption prediction on JET and ASDEX upgrade

Olivier Sauter, Basil Duval, Ambrogio Fasoli, Stefano Coda, Timothy Goodman, Yves Martin, Jonathan Graves, Jean-Marc Moret, Patrick Blanchard, Holger Reimerdes

The aim of this paper is to present a signal processing algorithm that, applied to the raw Locked Mode signal, allows us to obtain a disruption indicator in principle exploitable on different tokamaks. A common definition of such an indicator for different ...

2019

Validation of the ICRF antenna coupling code RAPLICASOL against TOPICA and experiments

Olivier Sauter, Basil Duval, Stefano Coda, Timothy Goodman, Yves Martin, Jean-Marc Moret, Duccio Testa, Patrick Blanchard, Bruno Marchand, Holger Reimerdes

In this paper we validate the finite element code RAPLICASOL, which models radiofrequency wave propagation in edge plasmas near ICRF antennas, against calculations with the TOPICA code. We compare the output of both codes for the ASDEX Upgrade 2-strap ante ...

IOP Publishing Ltd2019