Publications related to Direct energy conversion

Equilibrium pressure limits in stellarators

This thesis delves into the potential of magnetic fusion energy, and in particular focuses on the stellarator concept. Stellarators use external coils to produce 3-dimensional (3D) magnetic fields that confine a thermonuclear plasma in a topologically toro ...

EPFL2023

Implementation of energy transfer technique in ORB5 to study collisionless wave-particle interactions in phase-space

Laurent Villard, Alberto Bottino, Emmanuel Lanti, Noé Thomas Elie Ohana, Emanuele Poli

A new diagnostic has been developed to investigate the wave-particle interaction in the phase-space in gyrokinetic particle-in-cell codes. Keeping information about energy transfer terms in the velocity space, the technique has been implemented and tested ...

2021

Fully Soft-Switched High Step-Up Nonisolated Three-Port DC-DC Converter Using GaN HEMTs

Marco Mattavelli, Elison de Nazareth Matioli, Georgios Kampitsis, Rasoul Faraji

In this article, a soft-switched nonisolated high step-up multi-input dc-dc converter is proposed. The proposed converter has overcome the hard switching problem of the conventional boost three port converter (boost-TPC) by providing zero-voltage-switching ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Megawatt power generation of the dual-frequency gyrotron for TCV at 84 and 126 GHz, in long pulses

Timothy Goodman, Stefano Alberti, Minh Quang Tran, Jean-Philippe Hogge, Damien Fasel, Matthieu Toussaint, Ugo Siravo, Jérémy Genoud, Jérémie Dubray, Jonathan Sylvain Masur, Christian Moura, Blaise Marlétaz, Ioannis Pagonakis, Konstantinos Avramidis

In the frame of the TCV Tokamak upgrade, two 84/126 GHz/2 s dual frequency gyrotrons designed by SPC and KIT and manufactured by THALES will be added to the existing EC-System. The first unit has been delivered to EPFL-SPC and tested. In the commissioning ...

2020

Advanced linear models for gyro-backward wave instabilities in gyrotrons

Jérémy Genoud

Parasitic oscillations excitation is one of the main point hindering high-power gyrotron operation for fusion application. These instabilities, besides being dangerous for the gyrotron components, could possibly degrade the electron beam quality before it ...

EPFL2019

From W7-X Towards ITER and Beyond: 2019 Status on EU Fusion Gyrotron Developments

Stefano Alberti, Jean-Philippe Hogge, Damien Fasel, Jérémy Genoud, Jérémie Dubray, Ioannis Pagonakis, Blaise Marlétaz, Konstantinos Avramidis

In Europe, the research and development with main focus on achieving robust industrial designs of series gyrotrons for electron cyclotron heating and current drive of today's nuclear fusion experiments and towards a future DEMOnstration fusion power plant ...

IEEE2019

Diamond Window Technology for Electron Cyclotron Heating and Current Drive: State of the Art

Konstantinos Avramidis

Nuclear fusion power plants require electron cyclotron (EC) heating and current drive (H&CD) systems for plasma heating and stabilization. High-power microwave beams between 1 and 2?MW generated by gyrotrons propagate in a dedicated waveguide transmission ...

TAYLOR & FRANCIS INC2019

MHD Stability and Energy Principle for Two-Dimensional Equilibria without Assumption of Nested Magnetic Surfaces

Laurent Villard, Andrei Martynov

Abandoning the assumption of nested magnetic surfaces in tokamak plasma expands the field of research and opens up new approaches for both theoretical and experimental plasma physics. The computer code KINX for calculations of the ideal MHD stability was d ...

PLEIADES PUBLISHING INC2019

Overview of recent gyrotron R&D towards DEMO within EUROfusion Work Package Heating and Current Drive

Jean-Philippe Hogge, Jérémy Genoud, Ioannis Pagonakis, Martin Schmid, Konstantinos Avramidis

Gyrotron R&D within the EUROfusion Work Package Heating and Current Drive (WPHCD) is addressing the challenging requirements posed on gyrotrons by the European concept for a demonstration fusion power plant (EU DEMO). These requirements, as specified withi ...

IOP Publishing Ltd2019

Design and implementation of quasi-optical components for the upgrade of the TCV EC-system

Timothy Goodman, Stefano Alberti, Jean-Philippe Hogge, Laurie Porte, Matthieu Toussaint, Florian Ramseyer

The EC-system of the TCV tokamak is progressively being upgraded with the addition of two MW-class dual-frequency gyrotrons (84 and 126 GHz/2s/1MW). In order to connect the two gyrotrons to the existing low field side and top launchers, new waveguide routi ...

ELSEVIER SCIENCE SA2019

Recent experiments with the European 1MW, 170GHz industrial CW and short-pulse gyrotrons for ITER

Stefano Alberti, Minh Quang Tran, Jean-Philippe Hogge, Christian Schlatter, Francisco Sanchez, Ioannis Pagonakis, Jérémy Genoud, Konstantinos Avramidis

The European Gyrotron Consortium (EGYC) is developing the European 1 MW, 170 GHz Continuous Wave (CW) industrial prototype gyrotron for ITER in cooperation with Thales Electron Devices (TED) and Fusion for Energy (F4E). This conventional, hollow-cavity gyr ...

ELSEVIER SCIENCE SA2019

Metrology techniques for the verification of the alignment of the EU gyrotron prototype for ITER

Stefano Alberti, Jean-Philippe Hogge, Francisco Sanchez, Ioannis Pagonakis, Konstantinos Avramidis

The EU gyrotron for the ITER Electron Cyclotron (EC) heating system has been developed in coordinated efforts of the EGYC Consortium, Thales ED (TED) and Fusion for Energy (F4E) and under the supervision of ITER Organization Central Team. After the success ...

E D P SCIENCES2019

Overview of Recent Gyrotron R&D at KIT in View of the EU DEMO

Minh Quang Tran, Ioannis Pagonakis, Carl Love Mikael Råman Vinnå, Konstantinos Avramidis

A large part of the gyrotron R&D activities at Karlsruhe Institute of Technology focus on addressing challenging requirements posed on gyrotrons by the European concept for a demonstration fusion power plant (EU DEMO). This paper reports on the progress of ...

IEEE2018

Conceptual design of the EU DEMO EC-system: main developments and R&D achievements

Stefano Alberti, Minh Quang Tran, Falk Hans Braunmüller, Ioannis Pagonakis, Emanuele Poli, Konstantinos Avramidis

For the development of a DEMOnstration Fusion Power Plant the design of auxiliary heating systems is a key activity in order to achieve controlled burning plasma. The present heating mix considers electron cyclotron resonance heating (ECRH), neutral beam i ...

IOP Publishing Ltd2017

Conductor Performance of CCCN3, CCCN4 and CCCN5 Samples for ITER CC Coils

Pierluigi Bruzzone, Kamil Sedlák, Boris Stepanov, Fang Liu, Bo Liu

The conductor for the ITER Correction Coils (CC) is manufactured in China and is tested in the SULTAN facility. The third China CC conductor for the qualification SULTAN test sample (CCCN3) was prepared from a 200 m long CC conductor unit length (Phase II) ...

IEEE Institute of Electrical and Electronics Engineers2016

Progress on the upgrade of the TCV EC-system with two 1MW dual-frequency gyrotrons

Stefano Alberti, Timothy Goodman, Minh Quang Tran, Jean-Philippe Hogge, Jérémy Genoud, Trach-Minh Tran, Ioannis Pagonakis, Konstantinos Avramidis

The upgrade of the electron cyclotron (EC) system of the TCV tokamak has entered in its realization phase. The MW-class dual-frequency gyrotron design (84 or 126GHz/2s), based on the 140GHz W7-X gyrotron, is finalized and a contract for the manufacturing o ...

IEEE2016

Upgrade of a 30 kV/10 mA anode power supply for triode type gyrotron

Stefano Alberti, Jean-Philippe Hogge, Damien Fasel, Ugo Siravo, Jérémie Dubray, Philippe Marmillod, Albert Perez, Blaise Marlétaz

The RF power of a gyrotron with a triode type magnetron-injection-gun (MIG) can be directly controlled via the voltage applied between its anode and its cathode. Hence, the performance of this type of gyrotron relies directly on the possibilities offered b ...

Elsevier Science Sa2015

Novel aspects of plasma control in ITER

Olivier Sauter, Federico Alberto Alfredo Felici, Jonathan Bryan Lister, Sun Hee Kim

ITER plasma control design solutions and performance requirements are strongly driven by its nuclear mission, aggressive commissioning constraints, and limited number of operational discharges. In addition, high plasma energy content, heat fluxes, neutron ...

Amer Inst Physics2015

Turbulent regimes in the tokamak scrape-off layer

Annamaria Mosetto

The tokamak scrape-off layer (SOL) is the plasma region characterized by open field lines that start and end on the vessel walls. The plasma dynamics in the SOL plays a crucial role in determining the overall performance of a tokamak, since it controls the ...

EPFL2014

Interaction Between Fast Ions and Microturbulence in Thermonuclear Devices : Theory and Modelling

Mattia Albergante

The work carried out in this thesis focuses on the interaction between fast ions and turbulence. The aim of the project is to explore this phenomenon and develop the numerical framework required for investigations on present day machines and predictions fo ...

EPFL2011