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.