Time and spectrally resolved fluorescence of Cl*2 and ArCl* in Cl2 doped Ar Under state selective pulsed photoexcitation with synchrotron radiation

Synchrotron Radiation is used to selectively excite chlorine and Cl₂ doped argon in the VUV region. Stationary fluorescence and excitation spectra of the 1¹Σ _u ⁺ , 2¹Σ _u ⁺ and 2³Πg Cl ₂ ^* states and of the ArCl*(B?X) transition are obtained. The excitation threshold of ArCl*(B) in Ar/Cl₂ system is found to be 1,285±5 Å and that of ArCl(C) at ～1,260 Å. The formation of ArCl* and Cl*₂(2³Πg) is discussed in terms of recent potential curves data. A detailed time resolved study is reported which allows us to determine precisely the radiative lifetime of ArCl*(B) state (5.2 ns) and numerous kinetic parameters of this system, to estimate theC state energy and to discuss the relaxation and mixing process of the ArCl*(B) and (C) states. A two ladder multilevel kinetic model is described which accounts for the experimental results and shows the difficulty of studying this particular ArCl* system as compared to the closely related XeCl* and KrCl* ones.