Spatially resolved ozone densities and gas temperatures in a time modulated RF driven atmospheric pressure plasma jet: An analysis of the production and destruction mechanisms

摘要

In this work, a time modulated RF driven DBD-like atmospheric pressure plasma jet in Ar + 2%O_2, operating at a time averaged power of 6.5 W is investigated. Spatially resolved ozone densities and gas temperatures are obtained by UV absorption and Rayleigh scattering, respectively. Significant gas heating in the core of the plasma up to 700 K is found and at the position of this increased gas temperature a depletion of the ozone density is found. The production and destruction reactions of O_3 in the jet effluent as a function of the distance from the nozzle are obtained from a zero-dimensional chemical kinetics model in plug flow mode which considers relevant air chemistry due to air entrainment in the jet fluent. A comparison of the measurements and the models show that the depletion of O_3 in the core of the plasma is mainly caused by an enhanced destruction of O_3 due to a large atomic oxygen density.