Interpretation of Broadband Emission from a Gas-Discharge Krypton–Xenon Plasma

Abstract

The broadband continuum emission that was previously observed in a gas-discharge plasma of a krypton-xenon mixture is interpreted as an emission of KrXe* and Xe2 molecules due to the bound-free transition 0+(3P1) → 0+(1S0). For the vibrational levels v = 0–5 of the 0+(3P1), 0+(1S0) state of the KrXe* molecule, the relative intensities I v (λ) of the transitions v, 0+(3P1) → e, 0+(1S0) are calculated as functions of the wavelength λ using data from the literature on the internuclear potentials 0+(3P1) and 0+(1S0) and the dipole moment functions. From comparison with the experimental spectra, the population distribution over the vibrational levels of the 0+(3P1) state of the KrXe* and Xe2 molecules is obtained and the vibrational temperature is determined for different methods of excitation of the spectra. It is noted that the internuclear potentials used ensure a satisfactory description of the contribution of the radiation from the Xe2 molecule to the experimental spectrum. At the same time, the modeled continuum emission of the KrXe* molecule turned out to be shifted toward the short-wavelength range by 5–7 nm, while its width (5–6 nm) proved to be half as broad as the experimental width.