Xenon low-n Rydberg states in supercritical argon near the critical point

We present vacuum ultraviolet absorption spectra and an asymmetric line shape simulation of the 6s and 6s′ Rydberg states (including the blue satellite bands) of xenon doped into argon, from low argon number density to the density of the triple point liquid, at both non-critical temperatures and near (+0.5 °C) the critical isotherm of argon (i.e., −122.3 °C). The argon-induced shift in the simulated primary transition of the Xe 6s and 6s′ Rydberg states is presented as a function of argon number density for non-critical temperatures and along an isotherm near the critical temperature. This shift demonstrates a perturber critical point effect on the transition energies of low-n dopant Rydberg states.