Measurement of excitation temperature on a microwave induced atmospheric plasma

Summary form only given, as follows. Utilizing a 500 W, 2.45 GHz microwave system, an argon-assisted plasma was produced at atmospheric pressure. Stable generation of the plasma required optimized conditions such as appropriate quartz tube dimension, gas flow rate etc. Optical emission spectroscopy used for spectral line identification revealed the existence of oxygen radicals as well as argon ions and neutrals inside the plasma. Measurement of the excitation temperature was performed by using a Boltzmann plot. The result shows that it is a function of argon gas flow rate. It was also found that the plasma showed behavior as a recombining plasma due to cooling by the incoming cold argon gas.