Method and apparatus for generating radiation in the wavelength range from about 1 nm to about 30 nm, and use in a lithography device or in metrology

A method and an apparatus generate radiation in the wavelength range from about 1 nm to about 30 nm by an electrically operated discharge, which can be used in lithography or in metrology. A working gas is provided between two electrodes. Plasma is ignited in the working gas to generate radiation which is forwarded via an opening for further use. Debris particles are produced in at least one region of at least one of the electrodes. To retain the debris particles, the region is arranged with respect to the opening in such a way that movement paths of the debris particles run at least predominantly outside an area delimited by the opening.