Temperature-dependent photoabsorption cross-section of cyano-diacetylene in the vacuum UV

Nicolas Fray (1) , Yves Bénilan (1) , Marie-Claire Gazeau (1) , Antoine Jolly (1) , M. Schwell (1) , Emmanuel Arzoumanian (1) , T. Ferradaz (1) , Et Es-Sebbar (1) , Jean-Claude Guillemin (2)

1 LISA (UMR_7583) - Laboratoire Interuniversitaire des Systèmes Atmosphériques
2 ISCR - Institut des Sciences Chimiques de Rennes

Using synchrotron radiation as a tunable VUV light source, we have measured, for the first time, the absolute photoabsorption cross sections of HC5N with a spectral resolution of 0.05 nm in the region between 80 and 205 nm from 233 to 298 K. The measured cross sections are used to predict the HC5N photodestruction rate in the solar system and to model a transmission spectrum in Titan's atmosphere. Comparing the latter with that acquired by the Ultraviolet Imaging Spectrograph on board the Cassini spacecraft, we have determined an upper limit of 2.7 × 10−5 on the HC5N abundance at 1100 km.

Domaines: Chimie organique; Planète et Univers [physics]

Nicolas Fray, Yves Bénilan, Marie-Claire Gazeau, Antoine Jolly, M. Schwell, et al.. Temperature-dependent photoabsorption cross-section of cyano-diacetylene in the vacuum UV. Journal of Geophysical Research. Planets, 2010, 115, pp.E06010-E06015. ⟨10.1029/2009JE003518⟩. ⟨hal-00757248⟩