Observations of gain on the I(P1∕22→P3∕22) transition by energy transfer from O2(aΔg1) generated by a microwave discharge in a subsonic-flow reactor

Abstract

The excitation of I(P1∕22) in the reactions of discharge-generated O2(aΔg1) and O(P3) with I2 has been investigated in a microwave discharge-flow reactor at 1.5Torr and ∼350K using a suite of optical absorption and emission diagnostics to detect O2(aΔg1), O, I(P1∕22), and I(P3∕22) with high sensitivity. For O2(aΔg1) yields of 0.20–0.25 generated by the microwave discharge, positive gain on the I(P1∕22→P3∕22) transition at 1.315μm was observed when O concentrations were reduced by reaction with added NO2. The results imply quenching mechanisms for I(P1∕22) which are much faster than direct collisional deactivation by O.