Publications by Konstantinos Avramidis

A new 3MW ECRH system at 105 GHz for WEST*

Stefano Alberti, Timothy Goodman, Jean-Philippe Hogge, Ioannis Pagonakis, Konstantinos Avramidis

The aim of the WEST experiments is to master long plasma pulses (1000s) and expose ITER-like tungsten wall to deposited heat fluxes up to 10 MW/m2. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, the installation of an ...

2023

Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X

Gregory Vogel, Eduardo Sanchez, Frank Rüdiger Wagner, Alberto Bottino, Hartmut Zohm, Jonathan Graves, Thomas Binderup Jensen, Michel Haas, Emiliano Fable, Joaquim Loizu Cisquella, Attila Bencze, Xiaoxue Han, Adnan Ali, Jieping Zhu, Jonathan Marc Philippe Faustin, Antoine Baillod, Konstantinos Avramidis, Nicola Vianello, Sheng Xu, Mike Machielsen, Ajay Kumar, Hui Wang, Shuai Liu

We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been ...

IOP Publishing Ltd2022

European 1 MW, 170 GHz CW Gyrotron Prototype for ITER - long-pulse operation at KIT -

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

The upgraded EU 1 MW, 170 GHz continuous wave (CW) industrial prototype gyrotron (TH1509U) for Electron Cyclotron Resonance Heating and Current Drive (ECRH&CD) in ITER was tested at the Karlsruhe Institute of Technology (KIT). The gyrotron surpassed the pe ...

IEEE2022

Experimental Testing of the European TH1509U 170-GHz 1-MW CW Industrial Gyrotron-Long Pulse Operation

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

The upgraded European 1-MW, 170-GHz continuous wave (CW) industrial prototype gyrotron (TH1509U) for electron cyclotron resonance heating and current drive in ITER was tested at the Karlsruhe Institute of Technology (KIT). In this work, we report on the ma ...

Institute of Electrical and Electronics Engineers2022

Tests and Qualification of the European 1 MW, 170 GHz CW Gyrotron in an ITER relevant configuration at SPC

Stefano Alberti, Timothy Goodman, Jean-Philippe Hogge, Francisco Sanchez, Jérémy Genoud, Konstantinos Avramidis

After an initial testing period at the Karlsruhe Institute of Technology, the upgraded EU 1 MW, 170 GHz continuous wave (CW) industrial prototype gyrotron (TH1509U) for Electron Cyclotron Resonance Heating and Current Drive (ECRH&CD) in ITER has been trans ...

IEEE2022

Integration concept of an Electron Cyclotron System in DEMO

René Chavan, Minh Quang Tran, Hartmut Zohm, Konstantinos Avramidis

The pre-conceptual layout for an electron cyclotron system (ECS) in DEMO is described. The present DEMO ECS considers only equatorial ports for both plasma heating and neoclassical tearing mode (NTM) control. This differs from ITER, where four launchers in ...

2021

A Validation Roadmap of Multi-Physics Simulators of the Resonator of MW-Class CW Gyrotrons for Fusion Applications

Stefano Alberti, Francisco Sanchez, Konstantinos Avramidis

For a few years the multi-physics modelling of the resonance cavity (resonator) of MW-class continuous-wave gyrotrons, to be employed for electron cyclotron heating and current drive in magnetic confinement fusion machines, has gained increasing interest. ...

MDPI2021

Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Minh Quang Tran, Hartmut Zohm, Emiliano Fable, Konstantinos Avramidis, Emanuele Poli, Giovanni Tardini

An Electron Cyclotron Wave (ECW) system will be used in the European DEMO for the stabilization of Neoclassical Tearing Modes (NTMs). In order to avoid movable mirrors in the harsh environment close to the plasma and to simplify the NTM launcher integratio ...

2021

Th1509U European 170 Ghz 1 Mw Cw Industrial Gyrotron Upgrade

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

This paper describes the status on the upgrade of the first European gyrotron prototype for ITER, manufactured by Thales. The upgraded prototype, TH1509U, is now being tested to verify the performance improvements and to assess the compliance with ITER ECR ...

IEEE2021

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

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

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

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

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

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

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

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

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 on recent progress in magnetron injection gun theory and design for high power gyrotrons

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

The magnetron injection gun (MIG) is one of the most critical subcomponents in gyrotrons. The electron beam, which has the primary role on the gyrotron operation, is generated and configured at this part of the tube. The electron beam properties determine ...

E D P SCIENCES2019

Towards Advanced Fusion Gyrotrons: 2018 Update on Activities within EUROfusion

Stefano Alberti, Minh Quang Tran, Ioannis Pagonakis, Konstantinos Avramidis, Martin Schmid

During the ongoing pre-concept phase (2014 - 2020) for a possible future European DEMOnstration Fusion Power Plant (DEMO) the activities within EUROfusion WP HCD EC Gyrotron R&D and Advanced Developments are focusing on options for near-term solutions, and ...

E D P SCIENCES2019

Report of recent experiments with the European 1 MW, 170 GHz CW and SP prototype gyrotrons for ITER

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

The European 1 MW, 170 GHz industrial CW prototype gyrotron has been designed within EGYC (European GYrotron Consortium) in collaboration with the industrial partner Thales Electron Devices (TED) and under the coordination of Fusion for Energy (F4E). This ...

E D P SCIENCES2019

Manufacturing and Test of the 1 MW Long-Pulse 84/126 GHz Dual-Frequency Gyrotron for TCV

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

An 1 MW long-pulse (2s), 84/126 GHz dual frequency gyrotron has been produced by THALES MSI, France responding to the needs for upgrading the ECH system of the TCV tokamak The initial tests of the prototype carried out at EPFL, Switzerland, have verified a ...

IEEE2019

DEMO-Relevant Gyrotron Research at KIT

Minh Quang Tran, Ioannis Pagonakis, Konstantinos Avramidis

The DEMO-relevant gyrotron research at Karlsruhe Institute of Technology is driven by the European concept for a demonstration fusion reactor (EU DEMO). This paper reports on the recent results of the theoretical and experimental studies towards the develo ...

IEEE2019