Atmospheric-Pressure Plasma Jet in $\hbox{He/H}_{2} \hbox{O}$ Mixture

Plasma jets have been proven to be an excellent source because of their several novel applications. However, little is known about the effect of adding water vapor to the feed gas. We investigated the dietetic barrier discharge plasma jet in pure helium and He/water-vapor mixture. This paper presents the plasma dynamics and its properties obtained by time-resolved imaging and results of emission spectra in both feed gases. Addition of water vapor results in a decrease of the jet plume length and an increase of OH radical intensity in emission spectra. Therefore, DBD plasma jet is an efficient source for OH radical production, where yield of radicals and plume length can be controlled by variation of water-vapor content in feed gas.