TY - JOUR TI - Generation of 1.5 MW-140 GHz Pulses with the Modular Pre-Prototype Gyrotron for W7-X AU - Ioannidis, Z.C. AU - Avramidis, K.A. AU - Rzesnicki, T. AU - Chelis, I. AU - Gantenbein, G. AU - Illy, S. AU - Jin, J. AU - Pagonakis, I.G. AU - Thumm, M. AU - Jelonnek, J. JO - IEEE Electron Device Letters PY - 2021 VL - 42 TODO - 6 SP - 939-942 PB - Institute of Electrical and Electronics Engineers, Inc. (IEEE) SN - 0741-3106, 1558-0563 TODO - 10.1109/LED.2021.3073221 TODO - Cyclotrons; Electron cyclotron resonance; Gyrotrons; Stellarators; Tokamak devices, Continuous wave gyrotrons; Electron beam optics; Electron cyclotron resonance heating; Experimental campaign; Experimental verification; Short pulse; WENDELSTEIN 7-X, Ultrafast lasers TODO - In anticipation of an Electron Cyclotron Resonance Heating system upgrade for the stellarator Wendelstein 7-X, a 1.5 MW - 140 GHz continuous-wave gyrotron is under development. In order to provide a first experimental verification of the scientific RF and electron beam optics design of the gyrotron with ms pulses, the Karlsruhe Intitule of Technology has developed a short-pulse pre-prototype gyrotron. In this work, we present details regarding the construction of the pre-prototype as well as measurements from the first experimental campaign delivering up to 1.6 MW in short pulses. © 1980-2012 IEEE. ER -