High resolution absorption cross-section measurements of the Schumann-Runge bands of O2 by VUV Fourier transform spectroscopy

The photoabsorption spectrum of the O-2 Schumann-Runge bands was measured with resolution comparable to the Doppler widths by using the VUV Fourier transform spectrometer from Imperial College, London, combined with synchrotron radiation as a continuum light source at the Photon Factory, KEK, Japan. The analysis of the (12,0)-(17,0) bands of the Schumann-Runge system provides accurate rotational line positions as well as the line intensities from 185 to 175nm. Molecular constants of the v' = 12 to 17 levels of the B(3)Sigma(u)(-) state have been determined. The (v', 0) band oscillator strengths were determined as 2.38, 2.62, 2.70, 2.66, 2.40, and 2.12 x 10(-5) for the bands from v' = 12 to 17, respectively. (C) 2003 Elsevier Science (USA). All rights reserved.