Measurements of the Schumann-Runge Bands of O2 with VUV-FT Spectrometer and Synchrotron Radiation Source

Current research on the Earth’s upper atmosphere requires molecular parameters of unprecedented detail and accuracy. State-of-the-art models of the vacuum-ultraviolet (VUV) absorbing properties of the atmosphere call for absorption cross sections with details on the scale of the Doppler linewidths (i.e., 0.1 to 0.15 cm−1 at 295 K). As a consequence, spectroscopic data at resolving powers of the order of 106 are needed. Current particular needs are for ultrahigh resolution absorption cross section data for some bands of NO and O2 in the UV to VUV region. To meet some of these requirements, we have used a UV Fourier transform (FT) spectrometer at Imperial College (IC) to measure the Herzberg I bands of O2 [1,2] and the δ (0,0) band of NO [3]