A collisional radiative model of the argon ion system tested for a large range of electron densities

The authors previously reported on a comparison between a Collisional Radiative Model (CRM) for the argon ion system and density measurements of the 4s and 4p group of that system from the plasma column of a hollow cathode arc (HCA) (see Physica vol.94C, p.369, 1978). It appeared that there was a factor 3 discrepancy between the model and the experimental data for the 4p group. Measurements with a new type of HCA showed an increasing discrepancy with the existent model with increasing density, so that it was evident that this model was not adequate to give a good explanation of the experimental behaviour of excited groups over the whole density range. The authors have modified induced processes to and from the doubly ionized ground levels