Generation And Characteristics Of Atmospheric Pressure Jet Of Cold Plasma

The atmospheric pressure discharges (APDs) have many advantages because they do not need a high vacuum system and show to be of great prospect for a number of industrial applications. For this reason, there has been increasing interest in APDs, especially atmospheric pressure glow discharge (APGD), in the global low temperature plasma fields.Recently, a few novel atmospheric pressure plasma sources have been developed, such as the one atmosphere uniform glow discharge plasma (OAUGDP), the atmospheric pressure surface discharge and the atmospheric pressure plasma jet (APPJ). The discharge regions of these plasma sources are so limited that they are not suitable to treat the bulky or complex objects except APPJ. In addition, APPJ can operate with various gas in open air without vacuum equipment, and the other atmospheric pressure plasma devices have no this predominance. Recently, there has been great interest in the APPJ because of its advantages.However, the plasma gas temperature of APPJ is 50-300°C; it is not suitable for treating those vulnerable objects. The treatment area of APPJ is small, and it should be enlarged.To resolve the problem of the APPJ, a set of atmospheric pressure cold plasma jet (APCPJ) setup has been developed in our lab and we had performed many kinds of experiments. The gas temperature of APCPJ is lower than APPJ and the cold plasma torch, and it only 25-30°C. We augment the treatment area of APCPJ by changing its shape of nozzle. The discharge character of the APCPJ is studied. The main of discharge is filamentary discharge when electrical source operate between 2-11 kHz and the peak value of voltage is fixed at 12kV; the main of discharge is "like glow discharge" when electrical source operate between 12-16kHz with the same peak value of voltage. The discharge changes from filamentary discharge to "like glow discharge", when the frequency of electrical source is fixed at 7kHz and the peak value of voltage is increased. The emission spectrum is used as the APCPJ diagnostic methods to study the plasma characteristics. Excitation temperatures of APCPJ in...