Absolute spatially and time‐resolved O, O3, and air densities in the effluent of a modulated RF‐driven atmospheric pressure plasma jet obtained by molecular beam mass spectrometry

In this paper, we report a molecular beam mass spectrometer study of a time‐modulated radiofrequency (RF)‐driven atmospheric pressure plasma jet in Ar + 1% O2. Time‐resolved measurements of the absolute density of O3 during the RF modulation period revealed a temporal increase of O3 densities at the start and end of the power modulation. This increase correlates with the increase in O2 due to plasma‐induced transient vortices in the gas jet. Pseudo‐one‐dimensional plug flow modeling of the axial species densities as a function of distance match well with the experimentally recorded trends. The obtained results were used to assess the importance of the O flux in previously reported ClO− production in saline by the same plasma jet. We report a molecular beam mass spectrometer study of a time‐modulated RF‐driven atmospheric pressure plasma jet. Time‐resolved measurements of the absolute density of O3 during the RF modulation period revealed a temporal increase of O3 densities at the start and end of the power modulation due to gas flow dynamics. Pseudo‐one‐dimensional plug flow modeling of the axial species densities match well with the experimentally recorded treads.