Interruption in Propagation of an Ar Atmospheric Pressure Plasma Jet Surrounded With Distilled Water

Surrounded with distilled water, a classic argon atmospheric pressure discharge device is employed to study the propagation of the plasma. By examining the high-speed photographs, a phenomenon of interruption is found at different flow rates. At 3 L/min, the interruption appears only at the downward stage of the applied voltage after the plasma jet has run into the ambient air. As the flow rate reaches up to 15 L/min, however, the interruption can be obtained at a rather low applied voltage and exists in both the upward and downward stages. It is believed that the active species flowing from the upstream to the downstream region may be the main cause.