Time-resolved study of the UV fluorescence of chlorine under synchrotron radiation excitation of Cl2/rare-gas mixtures

Abstract

UV fluorescence of pure Cl2 and Cl2/rare-gas mixtures has been investigated under selective, pulsed VUV excitation. In pure Cl2, a strong fluorescence between 1350 and 2000 A is found with typical radiative lifetimes of 3 ns. Addition of Kr(Ar) to Cl2 strongly quenches this fluorescence and let show up Kr(Ar)Cl* emissions as well as the Cl2 «laser» emission at 2580 A. The radiative lifetime of the Cl2 laser state is found to be 16 ns. Absorptions and emissions observed in this work are discussed in view of the results of time-resolved fluorescence spectroscopy and of recent theoretical results on the excited-potential curves of Cl2.