Formation kinetics of the triatomic excimer Ar2F

Detailed fluorescence measurements of electron beam-excited high pressure mixtures of Ar/F 2 and Ar/NF 3 have been made in order to investigate the processes leading to the formation of Ar 2 F*. Three-body collisional quenching of ArF* has been identified as a major formation mechanism. The third-order rate constant for this reaction has been measured to be k_{1} = (1.2 \pm 0.2) \times 10^{-30} cm 6 . s -1 . In addition quenching rates for collisional de-excitation of Ar 2 F* by argon and the fluoride donors NF 3 and F 2 have been determined. The radiative lifetime has been measured as 219 ± 15 ns. The possible formation of Ar 2 F* from long-lived excited argon neutrals when using intense excitation densities and low-donor pressures is also briefly discussed.