Oxygen Effects on a He/O2 Plasma Jet at Atmospheric Pressure

Summary form only given. A He/O₂ plasma jet has been developed that operates using radio frequency (RF) power and produces a stable homogeneous discharge at atmospheric pressure. An optical emission spectroscopy has been used to observe the electronically excited species from the plasma jet and the discharge characteristics for the different gas mixture of He/O₂ were studied with a current and a voltage probe. The results indicate that there is a relative optimum fraction of O₂ in the He/O₂ gas mixture from 0.5% to 1.5% for the relative larger intensity of the characteristic atomic oxygen line at 777 nm. The current and voltage waveform measurements show that there is a new discharge ´failure´ phenomena which is different from the conventional arcing that is often observed in other atmospheric pressure discharges. A possible explanation for the discharge failure has been given