Results on the 1 MW CW 170 GHz gyrotron TH1509UA for ITER and DTT at the FALCON test stand

¹ Swiss Plasma Center (SPC), Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
² European Joint Undertaking for ITER and the Development of Fusion Energy (F4E), Barcelona, E-08019, Spain
³ Department of Physics, National and Kapodistrian University of Athens (NKUA), University Campus, 15784, Athens, Greece
⁴ Istituto per la Scienza e la Tecnologia dei Plasmi, Consiglio Nazionale delle Ricerche, 20125 Milano, Italy
⁵ EniProgetti, 30175 Venezia Marghera, Italy
⁶ Department of Energy, Polytechnic of Milano, 20133 Milano, Italy
⁷ Department of Energy “Galileo Ferraris” (DENERG), Polytechnic of Turin, 10129 Torino, Italy
⁸ Institute for Pulsed Power and Microwave Technology, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
⁹ Microwave Imaging Sub-Systems, THALES, Vélizy-Villacoublay, France, F-78141
¹⁰ ENEA, Fusion and Nuclear Safety Department, C. R. Frascati, 00044 Frascati, Italy
¹¹ DTT S.C. a r.l., 00044 Frascati, Italy
¹² Department of Aerospace Science and Technology, National and Kapodistrian University of Athens, 34400 Psachna, Greece

^* e-mail: falk.braunmuller@epfl.ch

Published online: 15 November 2024

Abstract

In this contribution, the tests of the pre-series gyrotron TH1509UA for the Divertor Tokamak Test facility (DTT) at the FALCON test facility are presented. This versatile test bed proves useful for testing continuous wave (CW) high-power gyrotrons, but also serves as a platform for testing components for the transmission line or the Upper Launcher of ITER and DTT. The gyrotron has demonstrated a power level of 1.02 MW at the gyrotron output window, corresponding to 980 kW at the output of the Matching Optics Unit (MOU) with a power variation during the pulse of < 2% after a stabilisation period. Additionally, an efficiency of 40% has been demonstrated during five consecutive 100 s pulses. Compared to the previous version, TH1509U, this gyrotron demonstrates the successful prevention of parasitic mode excitation over a wide range of parameters around the design operating point. The potential for even higher power performance has been shown in short pulses but not explored in long pulses yet, which instead focused on demonstrating compliance with the required specifications for the DTT project.