Temperature dependence of absorption cross-section of H2O, HOD, and D2O in the spectral region 140–193 nm

Measurements of absolute photoabsorption cross-sections of H2O, D2O and HOD in the spectral range 140–195 nm were performed at 295, 275, and 250 K using a double-beam absorption cell with a synchrotron radiation source. The absorption cross-sections in the spectral range 150–174 nm are nearly invariant upon isotopic substitution, but become smaller for heavier isotopomers in the region λ>174 nm. For each isotopomer, absorption cross-sections are nearly temperature independent in the spectral range 140–173 nm, but exhibit a small negative temperature dependence for wavelengths greater than 173 nm.