Experimental determination of emission cross sections for electron-induced processes in a supersonic argon jet

The article discusses an original spectroscopic method for the study of supersonic argon jets in atomic and cluster flow regimes. The method is based on absolute measurements of the VUV radiation flux from a supersonic argon jet induced by a 1 keV electron beam. The integral radiation flux and spectral distribution of the radiation flux density of a supersonic argon jet in the range of 50–150 nanometers were measured, which made it possible to determine the density of the non-condensed atomic component, the fraction of condensate, and the density of clusters in a supersonic argon jet at given parameters of its flow into vacuum. The obtained parameters also allowed us to estimate the emission cross sections for the argon resonance lines Ar I (λ = 104.8 nm, λ = 106.7 nm) and the cluster continuum λ = 127 nm.