Sudden and Adiabatic Polarization Effects in Doped Rare Gases

The evolution of both the sudden and adiabatic polarization energies resulting from a rare gas interacting with a dopant ion was followed for the first time. The variation of these two polarization energies was determined by means of photoabsorption and photoionization up to rare-gas number densities of (23.0, 24.0, 11.3, and 6.6)×{}10²⁰ cm^-3 for He, Ne, Ar, and Kr, respectively. Both polarization energies were found to vary linearly with rare-gas number density. However, the slopes differ by more than 1 order of magnitude. This difference is explained in terms of a model which accounts for the different time scales of the two experiments.