A COLLISIONAL RADIATIVE MODEL OF THE ARGON ION SYSTEM TESTED FOR A LARGE RANGE OF ELECTRON DENSITIES V. Van Der Sijde, B.F.M. Pots and D.C. Schram J. Phys. Colloques, 40 C7 (1979) C7-23-C7-24 DOI: 10.1051/jphyscol:1979711