A plasma radiation source is improved in such a way that the lifetime of
the optics which is limited by the influence of debris is appreciably
increased. A gas curtain through which the radiation proceeding from a
source region in a vacuum chamber is emitted at a defined solid angle for
debris suppression along an axis of the mean propagation direction of the
radiation exits as a radially directed supersonic gas jet from a
propulsion nozzle of a gas jet vacuum pump, which propulsion nozzle is
arranged on the axis. The gas curtain is directed to an annular mixing
nozzle that is arranged coaxial to the axis and is guided out of the
vacuum chamber by a diffuser. This makes it possible to use source
arrangements having an optimal conversion efficiency but extensive
debris.