Spectral enhancement of a Xe-based EUV discharge plasma source

Spectra have been recorded from a Xe discharge capillary source in the extreme ultraviolet (EUV) region of the spectrum, between 10 and 18 nm. Features due to 4d–4f and 4d–5p transitions in a range of ions have been observed, with the 4d–4f emission from ions Xe8+–Xe12+ clearly identified in the spectrum. The power emitted into a range of bands in the EUV has been measured and the effects on the spectrum of adding SnO2 and In2O3 powders to the Xe discharge have been quantified. The influence of indium ions on the spectrum, in particular, is to increase the emission in the region of 14.3 nm by as much as 30% over the pure xenon spectrum.