ABSTRACT

This chapter describes flow measurement and effects in cold atmospheric pressure plasma jets followed by a section on measurements of short living atoms and molecules. The effluent zone is much more accessible to optical and other diagnostic methods compared to the core plasma region. This is one reason for the multitude of studies regarding the plasma effluent zone. For diagnostics of atmospheric pressure plasmas, the plasma sheath thickness has to be considered. As described for diagnostics of the core plasma, laser induced fluorescence spectroscopy is one of the most sensitive diagnostic techniques to study atoms and small molecules also in the effluent. With the rise of plasma actuators in aerospace engineering applications, particle-imaging velocimetry is increasingly used in plasma research. Short-living atoms and molecules are key species in plasma reactivity and set cold plasmas apart from equilibrium chemistry. In low-pressure reactive plasmas, mass spectrometry is commonly used to study the plasma generated molecular and atomic charged and neutral reactive species.