Intermediate and Wannier Excitons in Fluid Xenon

Reflectivity spectra of MgF₂---fluid-xenon interfaces obtained for a wide range of densities revealed that the $n=2$ Wannier exciton starts to appear at densities above 400 amagat (1 amagat of density for xenon corresponds to 2.7067×{}10¹⁹ atoms/cm³). The n^'=1 exciton appears at densities above about 100 amagats on the low-energy side of the parent 5p⁵6s [K=1/2] atomic state. The occurrence and evolution of these bands and of the previously reported $n=1$ band with density are discussed with use of conductivity relaxation times obtained by Huang and Freeman.