A comparison of self broadening and shift of helium, neon and argon emission lines

Abstract

Self broadening (van der Waals and resonance) and shift of Ne emission lines and van der Waals broadening and shift of He emission lines have been measured using a high pressure (0.5–3.0 atom), low current discharge. These results are compared with previous measurements in Ar and He to obtain a complete comparison of self broadening and shift of He, Ne and Ar emission lines. Oscillator strengths for the resonance transitions are obtained from the resonance broadening coefficients. The trend of the van der Waals broadening coefficients for the three noble gases is correctly predicted by a theory due to HINDMARSH et al. (4) in which a Lennard-Jones potential is used in the impact theory formalism. The measured line shifts cannot be accounted for by this theory and reflect the need for more accurate quantum mechanical calculations.