Measurements of air-broadening parameters of water vapour transitions in the 7520–8586 cm−1 spectral region

The water vapour line broadening (γ) and shift (δ) coefficients for 319 lines of 11 vibrational bands 2ν3, 2ν2 +ν3, 3ν2+ν3, 5ν2, 6ν2, ν1+ν3, ν1+ν2+ν3, ν1+2ν2, ν1+3ν2, 2ν1, and 2ν1+ν2 from the spectral region 7520–8586 cm–1 induced by air pressure were measured with a Bruker IFS 125 spectrometer. The measurements were performed at a spectral resolution of 0.01 cm–1 and over a wide air pressure range. The calculations of the line-shift coefficients δ were performed in the framework of a semi-classical method. The measured air-broadening coefficients γ were combined with literature data for air- and N2-broadening coefficients γ measured for the lines in the 380–22,593 cm–1 spectral region. Combined experimental data for N = 4110 measured coefficients γ of 76 vibrational bands of H2O molecules were fitted to the empirical functions. The computed coefficients γ derived from the fitted parameters were statistically compared with the measurements. The vibrational dependence of the measured γ values and their compatibility is discussed.

本数据集针对光谱区域7520–8586 cm⁻¹内11个振动带（2ν3、2ν2+ν3、3ν2+ν3、5ν2、6ν2、ν1+ν3、ν1+ν2+ν3、ν1+2ν2、ν1+3ν2、2ν1及2ν1+ν2）的319条谱线，采用布鲁克IFS 125型（Bruker IFS 125）傅里叶变换光谱仪，测量了气压诱导下的水蒸气谱线增宽系数（γ）与位移系数（δ）。本次测量的光谱分辨率为0.01 cm⁻¹，且覆盖了宽气压范围。谱线位移系数δ的计算采用半经典方法（semi-classical method）完成。将本次测得的空气增宽系数γ，与此前文献中针对380–22593 cm⁻¹光谱区域内对应谱线测得的空气及氮气（N₂）增宽系数γ的相关数据进行整合。将包含4110组实测值的水分子（H₂O）76个振动带谱线增宽系数γ的整合实验数据集，拟合得到经验函数。将由拟合参数推导得到的谱线增宽系数γ的计算值，与实测值进行了统计对比。文中还讨论了实测γ值的振动依赖性及其数据相容性。