LED based Fourier transform absorption spectroscopy of H217O in the 14900–15600 cm−1 spectral region

Abstract

The vibration-rotation absorption spectrum of 17O-enriched water vapor in the range 14900–15600 cm−1 was recorded for the first time by a Fourier Transform Spectrometer coupled to a multi-pass White-type cell providing an optical path length of 34.8 m at room temperature with a spectral resolution of 0.05 cm−1 using high luminance LED (light emitting diode) light source. The high signal-to-noise ratio allowed for the accurate determination of 1047 positions of water lines, of which 661 lines were attributed to the H217O water isotopologue. The rovibrational assignment was based on new variational calculations, which allowed retrieving 285 experimental rotational-vibrational energy levels belonging to twelve vibrational states of the H217O molecule: (410), (330), (311), (231), (212), (151), (033), (052), (113), (132), (180), and (081). The 3ν1+ν2+ν3, 2ν1+3ν2+ν3 and 4ν1+ν2 vibrational bands centered, respectively, at 15325.617, 15095.166 and 15322.533 cm−1, dominate the spectrum. A detailed comparison of the H217O line intensities recorded in this study with observed literature data and with recent high-precision variational calculations showed that the calculated intensities for the (231) - (000) band are weaker by 57% than the experimental ones. The data set obtained in this study will help to improve the quality of variational calculations for water vapor.