Ozone densities in the effluent of an APPJ

Ozone concentrations in the effluent of a plasma jet are measured using absorption spectroscopy. A COST atmospheric pressure plasma jet is used with a total plasma volume of 30 cubic mm [1]. The COST source is a reference source built to better characterize the parameters of -APPJs. -APPJs are being actively examined for applications in the medical field, including sterilization and wound treatment. Gas flows of 1-1.5 slm of helium, along with small admixtures of oxygen, less than 1%, are used. The absorption spectra are acquired using a broadband UV light source and an Echelle Spectra Analyzer. Densities of ozone are obtained by focusing on the Hartley band, which is characterized by a strong absorption peak at 255 nm [2]. Variable flow rates of oxygen and helium are considered, as well as changes in applied voltage to the plasma. [1] J. Golda et al., J. Phys. D: Appl. Phys., 49, 2016 [2] D. Ellerweg et al., Plasma Sources Sci. Technol., 21, 2012