Production of electronically excited iodine atoms, I(2P1/2), following injection of HI into a flow of discharge oxygen

The emission from the transition I*(5
²
P_{1/2}) \rightarrow
I(5
²
P_{3/2}
) at 1.315 μm following injection of HI into a microwave-discharged He/O
2
flow has been studied. Relative I*(5
²
P_{1/2}
) emission intensities have been recorded as a function of HI and O
²
flow rates and as a function of time after injection. Pulsed gain measurements using an iodine photodissociation laser as a source show that the ratio,
N_{I}*/ (N_{I} +N_{I}*,) \approx 0.15-0.25
, is less than that required for population inversion. This observation will be discussed in terms of known chemical processes involving O(
³
P
), HI, O
2
(
¹
Δ
g
), and iodine atoms.