Experimental conditions for vacuum ultraviolet laser spectroscopy
An efficient wavelength-tunable vacuum ultraviolet (VUV) laser source has been developed at our institute in recent years. This laser source works on the principle of sum-frequency mixing of dye laser pulses in a magnesium vapour medium, which is prepared in a crossed heat pipe system. The laser source is coupled to a pulsed supersonic expansion and is in use for spectroscopic measurements. In this paper, we present a complete characterization of the experimental setup. The source yielded 25-ns-long pulses of VUV radiation with peak power of approximately 1 mW. The wavelength is currently tunable over the range 142.7-146.7 nm with a spectral bandwidth of 0.25 ± 0.05 cm -1. Suggested refinements of the experimental technique include an increase in the repetition rate of the measurements and shorter gas pulses.