Towards a 1.5 MW, 140 GHz gyrotron for the upgraded ECRH system at W7-X

Konstantinos A. Avramidis, Zisis C. Ioannidis, G. Aiello, P. Benin, Ioannis Chelis, A. Dinklage, G. Gantenbein, S. Illy, John Jelonnek, J. Jin, H. P. Laqua, Alberto Leggieri, François Legrand, Alexander Marek, S. Marsen, Ioannis Gr. Pagonakis, Tobias Ruess, T. Rzesnicki, T. Scherer, D. Strauß, M. Thumm, Ioannis G. Tigelis, D. Wagner, Jörg Weggen, R. C. Wolf