Patent ID: 8723147

Claim:
An extreme ultraviolet light source comprising: a production site producing extreme ultraviolet radiation; a collector optics ( 6 ) for collimating the extreme ultraviolet radiation produced at the production site; a vacuum applied at a center of the collector optics ( 6 ) that actively pumps out of the device; and a pressurized influx of gas that forms a gas curtain between the production site and the collector optics ( 6 ) to protect the collector optics ( 6 ) from debris ( 4 ) generated at the production site, wherein the gas influx is directed in a way that it follows the surface of the collector optics ( 6 ), wherein the gas is used simultaneously as a coolant for the collector optics ( 6 ) by conducting it along a back side of the collector optics ( 6 ) before it reaches an injection point ( 12 ) where it begins to protect the surface of the collector optics ( 6 ) from deposition and erosion by debris, and is injected at the injection point ( 12 ) with a maximum stagnation temperature of 700 K, and wherein internal cooling is tailored to match heat flux on the surface of the collector optics ( 6 ) by controlling the mass flow of the gas on the back side of the collector optics ( 6 ) with an arrangement of turbulators ( 18 ).