INTERPRETATION OF LOW-PRESSURE BROADENING AND SHIFT IN THE ARGON SPECTRUM

Results of experiments on low pressure broadening and shift of 17 spectral lines of argon involving intermediate Rydberg states are interpreted in the framework of the impact theory. Using a treatment due to Kaulakys it is shown that in pure argon and in the Ar-He mixture the experimental data are in satisfactory agreement with those calculated on the basis of the Fermi pseudopotential and polarization interaction. On the other hand, for the Ar-Ne mixture the theoretical broadening and shift values computed from this treatment are in poor agreement with experiment. The role of Maxwellian averaging as well as the scattering length in the analysis of the broadening cross-sections are also discussed.