Homogenous Power Distribution Along Gyrotron Collector Walls

•A novel solution to flatten the power deposition profile along gyrotron collector walls.•The use of current with an Amplitude Modulation applied to a vertical collector coil homogenize the temperature profile.•Commercial off-the shelf power supplies are available to generate current with an Amplitude Modulation, at a minimal cost.•Solution very interesting for existing short pulse gyrotrons, already equipped with a vertical coil collector.EC RF power sources will play a major role in the future operation of large scale tokamaks (ITER, DEMO). A 1MW/170 GHz gyrotron is the standard RF power unit considered for ITER. Even though the efficiency of such devices has been significantly increased thanks to the depressed collector technique, the power deposited on the collector by the spent electron beam is still above 1MW. As a consequence, this power shall be spread along the collector walls to avoid overheating of the collector internal surface.