EUV source

The EUV radiation source of the invention comprises an irradiation chamber containing an irradiation zone into which a stream of radiation-generator material is generated such as a flow of xenon propagating along a direction (II-II) extending transversely relative to an optical axis (I-I). The irradiation zone is in the proximity of a diaphragm oriented on the optical axis (I-I) and putting the irradiation chamber into communication with a transmission chamber. Power laser beams strike the stream of radiation-generator material in the irradiation zone and produce EUV radiation which propagates through the diaphragm and which is conditioned in the transmission chamber by elliptical mirrors. Differential pumps maintain a pressure P in the transmission chamber that is well below the pressure P in the irradiation chamber. The low pressure in the transmission chamber ensures that the EUV radiation is transmitted with little attenuation to a zone of use, without requiring voluminous high speed pumps.