a chamber comprising a plasma formation region;

a radiation collector configured in the chamber and configured to collect radiation emitted at the plasma formation region and to direct the collected radiation towards an intermediate focus region; and

a radiation conduit disposed between the radiation collector and the intermediate focus region,

wherein the radiation conduit comprises at least one outlet on an inner surface of a wall of the radiation conduit for directing a protective gas flow, and at least one guide portion extending from the inner surface of the wall of the radiation conduit and configured to redirect the protective gas flow, and

wherein the radiation source comprises magnets for generating a magnetic field within the chamber, the magnets being configured to trap charged particles radiating from the plasma formation region.