A new 3MW ECRH system at 105 GHz for WEST

• DOI: 10.1016/j.fusengdes.2022.113360
• Publication Date: 2022-12-05T22:06:36Z
• Authors: Lena Delpech; Stefano Alberti; Konstantinos Avra...; Aline Ayreault; Tristan Batal; Jean-Michel Bernard; Francis Bouquey; Ioannis Chelis; Frederic Clairet; Elodie Corbel; Louis Doceul; Frederic Durand; Remi Dumont; Theo Fonghetti; Gerd Gantenbein; Pascal Garibaldi; Gerardo Giruzzi; Tim Goodman; Jean-Philippe Hogge; Stefan Illy; John Jelonnek; Jianbo Jin; Heinrich Laqua; Francois Legrand; Christophe Lievin; Philippe Magaud; Patrick Maget; Pierre Manas; Stefan Marsen; Xavier Regal-Mezin; Patrick Mollard; David Mouyon; Laurent Nicolas; Adam Ouerfelli; Ioannis Pagonakis; Benjamin Robinet; Tobias Ruess; Benjamin Santraine; Manfred Thumm; Zisis Ioannidis
• Keywords: Gyrotron; Tore Supra

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/m$^2$. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, the installation of an upgraded ECRH heating system, with a gyrotron performance of 1MW/1000s per unit, is planned in 2023. With the modifications of Tore Supra to WEST, simulations at a magnetic field B$_0$∼3.7T and a central density n$_{e0}$∼6 × 10$^{19}$ m$^{−3}$ show that the optimal frequency for central absorption is 105 GHz. For this purpose, a 105 GHz/1MW gyrotron (TH1511) has been designed at KIT in 2021, based on the technological design of the 140 GHz/1.5 MW (TH1507U) gyrotron for W7-X. Currently, three units are under fabrication at THALES. In the first phase of the project, some of the previous Tore Supra Electron Cyclotron (EC) system components will be re-installed and re-used whenever possible. This paper describes the studies performed to adapt the new ECRH system to 105 GHz and the status of the modifications necessary to re-start the system with a challenging schedule.