J. Phys. II France
Volume 2, Numéro 4, April 1992
Page(s) 801 - 812
DOI: 10.1051/jp2:1992167
J. Phys. II France 2 (1992) 801-812

XUV-laser spectroscopy on CO: isotope-selective predissociation rates

Pieternel F. Levelt, Wim Ubachs and Wim Hogervorst

Laser Centre Free University, Department of Physics and Astronomy, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands

(Received 5 November 1991, accepted 18 December 1991)

The K (4p $\sigma$) $^1\sum ^+$, v=0 and W (3s $\sigma$) $^1\Pi$, v=2 states in 12C 16O and 13C 16O have been studied in high resolution with extreme ultraviolet laser radiation in the wavelength range 94-97 nm. Accurate spectroscopic constants for both isotopes and states have been derived from absolute rotational line positions. From linewidths of individual rotational transitions predissociation rates for 12C 16 and 13C 16O in the W $^1\Pi\,\, v=2$ state have been deduced: $k_{\rm p} \,(^{12}$CO) $ \,\,= 1.15 \,(15) \times 10^{11}$ s -1 and $k_{\rm p}\, (^{13}$CO) $\,\, = 0.58 \,(13) \times 10^{11}$ s -1. The rate of photodissociation of K $^1\sum ^+$, v=0 was found to be smaller: $k_{\rm p} = 2.6\, (1.3) \times 10^{10}$ s -1 for both isotopes.

33.20N - 33.80G - 98.40C

© Les Editions de Physique 1992