Optical emission from atmospheric pressure nonequilibrium plasma

Stable atmospheric pressure nonequilibrium plasmas (APNEPs) can be sustained in a variety of gas environments at atmospheric pressure. APNEP may be used for the surface modification of materials either in-situ or downstream from the plasma. However, the precise nature of the active species in the plasma and the downstream afterglow are still not fully understood. Standard photographic images of nitrogen, air, helium, and argon APNEPs are presented here. In the case of nitrogen, complementary optical emission spectra to aid the identification of excited species are also reported