First high-resolution spectrum and line-by-line analysis of the 2ν2 band of HTO around 3.8 microns

Abstract

The high-resolution infrared spectrum of tritiated water vapor has been recorded at room temperature using a Fourier-transform spectrometer with a resolution of 0.0075 cm−1. We report 488 new experimental line positions in the 2450 to 2950 cm−1 range that were assigned to the 2ν2 band of HT16O, with rotational quantum numbers up to J=14 and Ka=5. The assigned lines were used to determine the spectroscopic constants of the 2ν2 band of HT16O in the A-reduced Watson Hamiltonian. No perturbations were observed. The comparison with variational calculations of line positions and intensities of HTO from the Tomsk database shows differences of up to several 0.1 cm−1 concerning the line positions, while the (relative) line intensities agree with the observed values within a few percent. The line list from this study may be useful for detection of gaseous traces of HTO using laser-based methods in the future.