Iodine monofluoride emission spectrum and formation kinetics in electron-beam-produced plasmas

Intense blue-green fluorescence from a structured band centered at λ∼484 nm has been observed from Ar, CF3I, and NF3 (or F2) gas mixtures (T=300 K) excited by a ∼3-ns FWHM electron beam. This emission is tentatively assigned to the E→A3π1 transition of the iodine monofluoride (IF) molecule. From the temporal behavior of the IF* and I2* (342 nm) emission, it has been determined that the IF (E) level is formed primarily by excitation transfer from I* (4P) states. The fluorescence efficiency of the IF (E→A) band and the IF* (E) state radiative lifetime have been estimated to be ∼6% (in 99.83% Ar/0.13% CF3I/0.04% NF3 mixtures. PTOTAL≈2300 Torr) and ∼15 ns, respectively. The emission band structure, the short IF (E) radiative lifetime, and the Franck-Condon shift between the E and A states suggest that IF* is an attractive candidate for a blue-green laser.