A lithographic apparatus includes a radiation source configured to produce extreme ultraviolet radiation, the radiation source including a chamber in which a plasma is generated; a collector mirror configured to reflect radiation emitted by the plasma; and a debris mitigation system including a gas supply system configured to supply a first gas flow toward the plasma, the first gas flow being selected to thermalize debris generated by the plasma, and a plurality of gas manifolds arranged at a location proximate the collector mirror, the gas manifolds configured to supply a second gas flow in the chamber, the second gas flow being directed toward the plasma to prevent thermalized debris from depositing on the collector mirror.