Interferometric measurement of line widths and frequencies of the S0(0) and S0(l) rotational Raman lines of H2

Abstract

The line shape and change in frequency of the line center have been accurately determined for the S₀(0) and S₀(1) rotational Raman lines of normal H₂ at densities from 2 to 38 amagat, and for the S₀(1) line for mixtures of normal H₂ in helium and argon at total densities from 7 to 85 amagat. For pure H₂ the absolute Raman displacement extrapolated to zero gas density was also measured for both rotational lines. The accuracy obtained, ± 0.002 cm⁻¹, results from the application of interferometric techniques to Raman spectroscopy and represents about an order of magnitude improvement over earlier measurements.