Annular apparatus for generating accelerated electrons

An annular apparatus for generating accelerated electrons, comprising an annular housing which delimits an annular evacuable space and has an annular electron exit window;

• at least one first reservoir containing a working gas;
• at least one first inlet for supplying the working gas from the first reservoir into the annular evacuable space;
• at least one first cathode and at least one first anode, between which a glow discharge plasma may be generated in the annular evacuable space by a first applied electrical voltage, wherein ions from the glow discharge plasma may be accelerated onto the surface of an annular second cathode and electrons emitted by the annular second cathode may be accelerated towards the annular electron exit window by a second electrical voltage applied between the annular second cathode and an annular second anode, wherein the housing is designed as a first cathode;
• wherein the first anode comprises a number of wire-like electrodes which extend completely or partially through the annular evacuable space, wherein a second reservoir contains a hydrocarbon-containing compound which may be admitted into the evacuable space through the at least one first inlet.