Publications by Guang-Yu Sun | EPFL Graph Search

Related publications (30)

The effect of plasma shaping on high density H-mode SOL profiles and fluctuations in TCV

Nicola Vianello, Benoît Labit, Holger Reimerdes, Christian Gabriel Theiler, Cedric Kar-Wai Tsui, Umar Sheikh, Guang-Yu Sun, Claudia Colandrea, Sophie Danielle Angelica Gorno, Luke Simons

The impact of plasma shaping on the properties of high density H-mode scrape-off layer (SOL) profiles and transport at the outer midplane has been investigated on Tokamaka configuration variable. The experimental dataset has been acquired by evolving the u ...

IOP Publishing Ltd2024

Metal-wire-embedded alumina insulating material using micro- and nanoscale 3D printing for surface flashover mitigation in a vacuum

Guang-Yu Sun

A micro- and nanoscale 3D printing technique is applied to fabricate a functional insulating material that mitigates surface discharge in a vacuum based on microscopic electron multipactor suppression. The proposed alumina ceramic insulator design consists ...

2022

Positive Streamer Initiation in SF6/CO2 Based on Zener's Field Ionization

Guang-Yu Sun

In this study, experiments were performed to measure the inception and breakdown voltages of SF6/CO2 mixed gases with varying mixing ratios at two different pressures (1 and 2 bar). Using the preliminary data obtained from the experiments, a 3D particle mo ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Experimental research on the TCV tokamak

Flavio Mauricio Martins E Silva, Vincent Masson, Abhilash Mathews, Olivier Sauter, Ambrogio Fasoli, Stefano Coda, Henri Weisen, Timothy Goodman, Yves Martin, Stefano Alberti, Duccio Testa, Ivo Furno, Patrick Blanchard, Benoît Labit, Jean-Philippe Hogge, Holger Reimerdes, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Alexander Karpushov, Antoine Pierre Emmanuel Alexis Merle, Umar Sheikh, Simon Van Mulders, Alessandro Pau, Yanis Andrebe, Cristian Galperti, Joan Decker, Jérémy Genoud, Marcelo Baquero Ruiz, Cedric Kar-Wai Tsui, Mengdi Kong, Matteo Vallar, Olivier Claude Martin Février, Davide Galassi, Guang-Yu Sun, Pedro Andres Molina Cabrera, Filippo Bagnato, Artur Perek, Claudia Colandrea, Sophie Danielle Angelica Gorno, Francesco Carpanese, Nicola Offeddu, Luke Simons, Aylwin Iantchenko, Maurizio Giacomin, Lorenzo Martinelli, Oleg Krutkin, Antoine Baillod, Federico Pesamosca, Dmytry Mykytchuk, Jesús Poley Sanjuán, Carl Mathias Paul Hoppe, Hugo De Oliveira, Benjamin Alexandre Vincent, Umesh Kumar, Garance Hélène Salomé Durr-Legoupil-Nicoud, Arsène Stéphane Tema Biwole, Massimo Carpita, Jean Arthur Cazabonne, Yuxuan Wang, Davide Mancini, Cassandre Ekta Contré, Stefano Marchioni, Samuele Mazzi, Reinart Andreas J. Coosemans, Gino Marceca, Renat Karimov, Elena Tonello, Michele Marin, Martim Zurita, Alessandro Balestri, Humberto Torreblanca Quiroz, Francesco Pastore, Daniele Hamm, Mackenzie Peter-Fulford Van Rossem, Emanuel Paul Huett, Nam Axel David Vu, Marta Mariarmanda Pedrini, Cristina Venturini, Hari Raj, Antonia Frank, Silvia Masillo

Tokamak à configuration variable (TCV), recently celebrating 30 years of near-continual operation, continues in its missions to advance outstanding key physics and operational scenario issues for ITER and the design of future power plants such as DEMO. The ...

IOP Publishing Ltd2024

Vlasov simulation of the emissive plasma sheath with energy-dependent secondary emission coefficient and improved modeling for dielectric charging effects

Guang-Yu Sun

A one-dimensional Vlasov-Poisson simulation code is employed to investigate the plasma sheath considering electron-induced secondary electron emission (SEE) and backscattering. The SEE coefficient is commonly treated as constant in a range of plasma simula ...

FRONTIERS MEDIA SA2022

The effect of microstructure on vacuum surface flashover

Guang-Yu Sun

The vacuum discharge along the dielectric surface, also called surface flashover, brings significant damages to the vacuum-solid insulation system. Here we implement shape-flexible, complex surface groove microstructures on the dielectric to mitigate the i ...

IEEE2021

X-point radiator and power exhaust control in configurations with multiple X-points in TCV

Holger Reimerdes, Christian Gabriel Theiler, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Olivier Claude Martin Février, Guang-Yu Sun, Filippo Bagnato, Artur Perek, Claudia Colandrea, Curdin Tobias Wüthrich, Sophie Danielle Angelica Gorno, Luke Simons, Lorenzo Martinelli, Garance Hélène Salomé Durr-Legoupil-Nicoud, Richard Alexander David Ducker, Ming Yin Kenneth Lee

Novel power exhaust solutions are being developed to address the challenge of integrating a high performance fusion core plasma with a well-protected divertor, if the single null configuration does not scale to a reactor device. This work aims to elucidate ...

American Institute of Physics (AIP)2024

Low‐Power Tunable Micro‐Plasma Device for Efficient and Scalable CO2 Valorization

Önder Soydal, Elison de Nazareth Matioli, Jeremy Luterbacher, Guang-Yu Sun, Hongkeng Zhu, Bartu Karakurt

Valorizing CO2 into chemical building blocks via efficient electrified processes could significantly decrease carbon emissions. In this work, a device that allows generation of tunable micro‐plasma modes (arc, pulsed, pulsed arc) on a chip for efficient, l ...

Wiley2025

Parallel flows as a key component to interpret Super-X divertor experiments

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Joaquim Loizu Cisquella, Olivier Claude Martin Février, Davide Galassi, Guang-Yu Sun, Artur Perek, Claudia Colandrea, Curdin Tobias Wüthrich, Sophie Danielle Angelica Gorno, Luke Simons, Lorenzo Martinelli, Massimo Carpita, Emanuel Paul Huett, Garance Hélène Salomé Durr-Legoupil-Nicoud

The Super-X Divertor (SXD) is an alternative divertor configuration leveraging total flux expansion at the Outer Strike Point (OSP). While the extended 2-Point Model (2PM) predicts facilitated detachment access and control in the SXD configuration, these a ...

IOP Publishing Ltd2024

Suppression of dielectric surface flashover induced by strong electromagnetic field at multiple spatial scales based on above/sub-surface discharge development mechanisms

Guang-Yu Sun

Spacecraft charging and electrostatic discharging (ESD) are prone to occur in harsh space environments. In particular, in the case of coupling strong electromagnetic field (EMF), ESD damages may occur at a low charging potential, posing a serious threat to ...

2024

The Influence of O-2 on Positive Streamer Initiation in Supercritical CO2 With Field Ionization Using a 3-D Particle Model

Guang-Yu Sun

In this work, the influence of varying mixing ratios of O-2 on positive streamer initiation in supercritical (SC) CO2 at different applied voltages was investigated using a 3-D particle model. Zener's model was included in the 3-D particle model to calcula ...

2021

Unveiling the role of dielectric trap states on capacitively coupled radio-frequency plasma discharge: dynamic charging behaviors

Guang-Yu Sun, Arnas Volcokas

The influence of charge trap states in the dielectric boundary material on capacitively coupled radio-frequency (RF) plasma discharge is investigated with theory and particle-in-cell/Monte Carlo collision simulation. It is found that the trap states of the ...

2021

Investigation of sheath structure in surface flashover induced by high-power microwave

Guang-Yu Sun

Flashover is a major limiting factor for the transmission and miniaturization of high-power microwave (HPM) devices. We conducted a study to investigate the developmental process of surface flashover on HPM dielectric windows through particle-in-cell-Monte ...

Aip Publishing2024

Tailoring Organic/Inorganic Interface Trap States of Metal Oxide/Polyimide toward Improved Vacuum Surface Insulation

Chao Wang, Guang-Yu Sun

High-voltage and high-power devices are indispensablein spacecraftfor outer space explorations, whose operations require aerospace materialswith adequate vacuum surface insulation performance. Despite persistentattempts to fabricate such materials, current ...

AMER CHEMICAL SOC2023

Impurity-seeded detachment in conventional and optimized TCV divertor geometry

Guang-Yu Sun

Nuclear fusion provides a potentially unlimited and clean energy source which motivates the development of fusion power plants. The tokamak is one of the most promising concepts for a future reactor, confining the fusion plasmas in a torus using strong mag ...

EPFL2025

A method to numerically determine the secondary electron yield considering effects of the surface morphology

Guang-Yu Sun

Secondary electron emission (SEE) of solid materials due to electron bombardment is influenced by numerous properties of materials, where the surface condition plays a critical role in the value of secondary electron yield (SEY). Here, a 3D random microstr ...

2021

Ultralow secondary electron emission and improved vacuum surface insulation of polyimide with scalable nanocomposite coating

Chao Wang, Guang-Yu Sun

Polymers with high surface electric insulation capability are greatly demanded in various electrical devices operating in vacuum ambient. Low secondary electron emission (SEE) is favorable to mitigate vacuum flashover by inhibiting the SEE avalanche across ...

ELSEVIER2022

Analytical model for estimating the equilibrium plasma quantities in an electron beam-plasma system

Guang-Yu Sun, Haomin Sun

We develop an analytical model for estimating the equilibrium quantities, such as electron temperature and number density, in an electron beam-plasma interaction system. This model provides a convenient way to calculate the effective electron temperature a ...

2024

Enhancing ion extraction with an inverse sheath in negative hydrogen ion sources for NBI heating

Guang-Yu Sun, Wayne Yang Wen Wei

Negative hydrogen ion (H-) sources employed in neutral beam injection (NBI) systems are subject to extraction efficiency issues due to the considerable volumetric losses of negative hydrogen ions. Here, we propose to improve the H- extraction by activating ...

IOP Publishing Ltd2023

Access to an ELM-suppressed X-point radiator regime in TCV snowflake minus configurations

Yinghan Wang, Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Olivier Claude Martin Février, Guang-Yu Sun, Artur Perek, Curdin Tobias Wüthrich, Sophie Danielle Angelica Gorno, Luke Simons, Martim Zurita, Daniele Hamm, Ming Yin Kenneth Lee

TCV’s operating regime with an X-point radiator (XPR) has been broadened by changing the magnetic geometry. XPRs have properties that could make them an attractive power exhaust solution for fusion reactors. These include the conversion of a high fraction ...

Elsevier2024