Abstract: A lithographic apparatus includes a radiation system that includes a source for producing a radiation beam, a contaminant trap arranged in a path of the radiation beam, and an illumination system configured to condition the radiation beam produced by the source, and a support for supporting a patterning device. The patterning device serves to impart the conditioned radiation beam with a pattern in its cross-section. The apparatus also includes a substrate table for holding a substrate, and a projection system for projecting the patterned radiation beam onto a target portion of the substrate. The contaminant trap includes a plurality of foils that define channels that are arranged substantially parallel to the direction of propagation of the radiation beam. The trap is provided with a gas supply system that is arranged to inject gas into at least one of the channels of the trap.

Abstract: An optical attenuator device operates to remove a part of a beam of radiation having a higher than average intensity using at least one optical attenuator element. The device has application in a radiation system, and/or a lithographic apparatus, in particular a scanning lithographic apparatus, wherein the optical attenuator element(s) are provided in a central part of the beam, for example perpendicularly to a scanning direction.