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The emission spectrum of a dc capillary discharge in krypton with a small (≤0.1%) xenon impurity has been experimentally studied in the 115-850-nm range. It is shown that most of the radiation energy is concentrated in a narrow VUV spectral band adjacent to the 146.96-nm resonance line of xenon and belonging to the heteronuclear Xe*Kr molecule. The power of the narrow-band VUV radiation and its angular dependence have been measured. A conclusion is drawn that the appearance of the narrow-band VUV radiation represents amplified spontaneous emission caused by transillumination of the broad-band amplifying medium by a narrow-band "seed."

The (2 + 1) photoionization mass spectra of Xe-2 molecules are studied in a supersonic jet upon excitation by laser radiation in the energy range 80321.3-77821 cm(-1), corresponding to the dissociation of the Xe-2 molecule into atoms Xe(S-1(0)) + Xe*(6p, 5d). Several vibrational progressions are observed, which are attributed to two-photon transitions of Xe-2 from the ground state to the excited states of the 0(g)(+), 1(g), and 2(g) symmetries. Based on the analysis of these progressions, the molecular constants of a number of excited states of Xe? are estimated.

This paper describes the technique and the results of measurement of the power and geometry of the VUV radiation beam from a dc capillary discharge in a mixture of krypton and xenon. The angular divergence of narrowband VUV radiation of the heteronuclear KrXe* molecule is shown to be narrower as compared to that of the discharge radiation in the range 200-1000 nm. The power of VUV radiation from a discharge tube 80 cm long is found to exceed 10 mW.