Impact broadening and shift of the Hα line by helium, neon, and argon

Observations are reported of the collision broadening and shift of the hydrogen-α line by helium, neon, and argon foreign gases. An analysis of the line profile from a microwave-excited discharge with allowance for Doppler broadening and fine structure yields the effect of foreign gas pressure on the spectral line shape. The classical theory of spectral line impact broadening together with an interatomic potential proposed previously for alkali–noble gas interactions correctly predicts the observed broadening and shift of the line.