Analysis of the ν₁+ν₃ band of T₂¹⁶O and the ν ₁ + ν ₃ and 2ν₂ + ν₃ bands of DT¹⁶O

We present the ν1+ν3 band of T216O and the ν1+ν3 and 2ν2+ν3 bands of DT16O that have been analysed for the first time using high-resolution infrared spectra of tritiated water vapour. The spectrum for T216O has been recorded from a custom-built light-pipe cell at room temperature using a Bruker 125HR Fourier-transform spectrometer at a resolution of 0.025cm−1. For the DT16O species, an optimised version of the optical cell with 10 times larger maximum activity with regard to previous studies has been employed. For the ν1+ν3 band of T216O, we report 206 new experimental line positions in the range from 4415 to 4645cm−1. In the range of 4780–5175cm−1, 356 new experimental line positions of the DT16O have been assigned for the ν1+ν3 band and 161 line positions for the 2ν2+ν3 band. The analysis agrees with previous observations showing a systematic shift of the individual line positions compared to the variationally calculated line positions from the Tomsk database. This shift is depending on the rotational quantum number Ka. For each band, the assigned lines were used to determine the spectroscopic constants of the <i>A</i>-reduced Watson-type Hamiltonian.

本研究首次利用氚化水蒸气（tritiated water vapour）的高分辨率红外光谱，完成了对T₂¹⁶O的ν₁+ν₃振动带，以及DT¹⁶O的ν₁+ν₃与2ν₂+ν₃振动带的解析。T₂¹⁶O的光谱通过定制光管池（custom-built light-pipe cell）在室温下采集，所用仪器为分辨率0.025 cm⁻¹的布鲁克（Bruker）125HR傅里叶变换光谱仪（Fourier-transform spectrometer）。针对DT¹⁶O样品，本研究采用了经优化的光学池，其最大活性较既往研究提升了10倍。针对T₂¹⁶O的ν₁+ν₃振动带，本研究报道了波数范围4415~4645 cm⁻¹内的206个全新实验谱线位置。在4780~5175 cm⁻¹的波数范围内，针对DT¹⁶O的ν₁+ν₃振动带，本研究归属了356个全新实验谱线位置；针对其2ν₂+ν₃振动带，则归属了161个谱线位置。本次解析结果与既往观测一致：相较于汤姆斯克数据库（Tomsk database）中变分计算得到的谱线位置，各条实验谱线位置存在系统性偏移，该偏移量随转动量子数Ka（rotational quantum number Ka）变化。针对每个振动带，本研究利用已归属的谱线，确定了A约化（A-reduced）沃森型哈密顿量（Watson-type Hamiltonian）的光谱常数。