Broadening and shifting of the Raman Q branch in pure D2 and D2–He mixtures, I: experimental results and comparison with theory

Abstract

We report the broadening and shifting of the Raman Q-branch lines in D2 and D2–He mixtures, all at 305.2 K. The width and shift of each line were extracted by fitting a simple Lorentzian profile to the experimental data. From a linear fit of the widths and shifts as a function of density we have determined broadening and shifting coefficients with an uncertainty of ±0.5%. None of the existing semiclassical or quantal calculations agree with the measurements at this level of accuracy. It is pointed out that the removal of certain approximations in the calculations should bring theory and experiment into closer agreement.