FIELD-INDUCED ABSORPTION IN HYDROGEN

Abstract

This paper reports an investigation of the fundamental rotation–vibration absorption induced in hydrogen by an electric field. The integrated absorption coefficients of the first four components of the Q branch have been measured for a range of field strengths at densities of 83.9 and 44.6 Amagat. The integrated absorption coefficient of the S(1) line has been determined at the higher density for one high field strength. The relative intensities of the Q components are in good agreement with the predicted ratios. Accurate experimental values of the matrix element of the mean value of the polarizability, (α)₀₁, and the matrix element of its anisotropy, (γ)₀₁ have been obtained. They are: (α)₀₁ = 0.968 × 10⁻²⁵ cm³, and (γ)₀₁ = 0.72 × 10⁻²⁵ cm³ at 83.9 Amagat, and are only slightly dependent on density. The frequencies of the lines have been measured. Only Q(1) and S(1) show a measurable shift with density. The optical collision diameter has been determined and is very small, 0.26 Å.