Formation kinetics of the triatomic excimer Ar2F*

Detailed fluorescence measurements of electron beam-excited high pressure mixtures of Ar/F2and Ar/NF3have been made in order to investigate the processes leading to the formation of Ar2F*. 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 bek_{1} = (1.2 pm 0.2) times 10^{-30}cm⁶. s^-1. In addition quenching rates for collisional de-excitation of Ar2F* by argon and the fluoride donors NF3and F2have been determined. The radiative lifetime has been measured as 219 ± 15 ns. The possible formation of Ar2F* from long-lived excited argon neutrals when using intense excitation densities and low-donor pressures is also briefly discussed.