An extreme ultra-violet lithographic apparatus for imaging a pattern onto a substrate includes a radiation system constructed and arranged to provide a beam of an extreme ultra-violet radiation, and an absorber arranged in the beam and constructed and arranged to absorb at least a portion of the radiation beam. The absorber has a volume configured to accommodate a flow of an absorbing gas. The flow is directed in a transverse direction with respect to the beam. The absorber includes a structure having an extreme ultra-violet radiation-transmissive beam entry area and an extreme ultra-violet radiation-transmissive beam exit area. The apparatus also includes a gas inlet actuator array configured to inject the gas into the volume and a gas outlet actuator array arranged to evacuate the gas from the volume.