A note on the excitation mechanisms and radial profiles of the Cd(II) 441.6 nm line in the positive column He-Cd+discharge

It is shown that radial profiles of the Cd(II) 441.6 nm line measured by McKenzie (1977) cannot be satisfactorily interpreted as resulting from the Penning excitation process with an additional smoothing-out effect, but can be interpreted in terms of the stepwise excitation and electron de-excitation processes.