Atomic-Oxygen Number Densities in Ar-O2 DBDs and Post-discharges with Small Initial O2 Fractions: Plug-Flow Model and Experiments

Abstract Number densities of oxygen atoms, n O , in Ar-O 2 mixtures with small initial fractions, $${x}_{{O}_{2}}$$ x O 2 < 1%, flowing through a dielectric-barrier discharge (DBD), are calculated using plug-flow reactor model, presuming that dissociation and excitation species solely driven by energy-transfer from long-lived excited Ar species, collectively denoted as Ar*. The rate which Ar* generated is the volume density power dissipated DBD. To obtain extended post-discharge (PD) regions large experiments were performed = 100 ppm. For such low time-dependence DBD early PD can be closed equation. Calculations compared optical emission spectroscopic (OES) results, utilizing proportionality O-atom intensity at 777.4 nm to . made accessible OES tandem setup second sensing discharge. Model testing experiment based on functional dependence DBD-residence time PD-delay time, respectively. Wall losses atoms asymmetrical reactors an alternative Chantry’s agreement between attained exit experimental results generally good while speed rise overestimated, due assumption constant wall-loss frequency, k W Compared literature data, orders magnitude higher least one order lower PD.