PREDISSOCIATION LINEWIDTHS OF THE (3,0)-(11,0) SCHUMANN-RUNGE ABSORPTION-BANDS OF O-18(2) AND O-16 O-18 IN THE WAVELENGTH REGION 180-196 NM

Predissociation linewidths of the (3,0)-(11,0) Scbumman-Runge bands of 18O2 and 16O 18O in the wavelength region 180-196 nm have been obtained from the published measurements of the absolute absorption cross sections of Yoshino et al. [Planet. Space Sci. 36, 1201 ( 1988); 37, 419 (1989)] and spectroscopic constants of these molecules of Cheung et al. [J. Mol. Spectrosc. 131, 96 ( 1988); 134, 362 (1989)]. The linewidths are determined as parameters in the nonlinear least-squares fitting of calculated to measured cross sections. Predissociation maxima are found at upper vibrational levels with v′ = 4 ,7, and 10 for 18O 2 and for 16O 18O. Our predissociation linewidths are mostly greater than previous experimental values for both isotopic molecules. © 1990 American Institute of Physics.