A study of acetylene collision broadening by hydrogen and nitrogen using a tunable laser spectrometer

Collision broadening of acetylene spectra by hydrogen and nitrogen was studied in the 14 μ m region using a diode laser spectrometer. A total of fifteen P(J) and Q(J) transitions in the υ₅ fundamental band were observed.

The reduced Lorentz-widths per unit pressure from the observed Voigt width were fitted to a model quadratic in the angular momentum, i.e., γ_L = γ_L⁰ + γ_C^(1)J + γ_C^(2)J2 results for the nitrogen broadened lines were 0.2260 milli-cm^-1/Torr for γ_L⁰, the collision broadened coefficient at J = 0, and γ_c⁽¹⁾ = -0.005005 and γ_c⁽²⁾ = 0.00013458 milli-cm^-1/Torr. The results for the hydrogen broadened lines were γ_C⁰ = 0.2169 milli-cm^-1/Torr, and γ_C⁽¹⁾ = -0.003937 and γ_c⁽²⁾ = 0.000114 milli-cm^-1/Torr.