Oxygen discharge and post-discharge kinetics experiments and modeling for the electric oxygen-iodine laser system

Laser oscillation at 1315 nm on the I( ²P _1/2) → ( ²P _3/2) transition of atomic iodine has been obtained by a near resonant energy transfer from O ₂(a ¹Δ) produced using a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels of complexity to the singlet oxygen generator (SOG) kinetics which are not encountered in a classic purely chemical O ₂(a ¹Δ) generation system. The advanced model BLAZE-IV has been introduced to study the energy-transfer laser system dynamics and kinetics. Levels of singlet oxygen, oxygen atoms, and ozone are measured experimentally and compared with calculations. The new BLAZE-IV model is in reasonable agreement with O ₃, O atom, and gas temperature measurements but is under-predicting the increase in O ₂(a ¹Δ) concentration resulting from the presence of NO in the discharge and under-predicting the O ₂(b ¹∑) concentrations. A key conclusion is that the removal of oxygen atoms by NO _x species leads to a significant increase in O ₂(a ¹Δ) concentrations downstream of the discharge in part via a recycling process; however, there are still some important processes related to the NO _x discharge kinetics that are missing from the present modeling. Further, the removal of oxygen atoms dramatically inhibits the production of ozone in the downstream kinetics.