A generator rotor for a generator, in particular a slowly rotating generator, of a wind turbine or a hydroelectric power plant. The rotor generator comprises a rotor belt for holding a plurality of pole shoes, a hub flange for fixing the generator rotor to a shaft, in particular a main shaft or a transmission shaft, of the wind turbine, or for fixing to a number of turbine blades of the hydroelectric power plant, and a carrier structure which is respectively non-rotatably connected to the rotor belt on the one hand and to hub flange on the other hand, wherein the rotor belt comprises a metallic material having a first degree of damping (D1) and at least one of: the carrier structure or the hub flange partially or completely comprises a material having a second degree of damping (D2), wherein the second degree of damping (D2) is higher than the first degree of damping (D1).