Formation of stable direct current microhollow cathode discharge by venturi gas flow system for remote plasma source in atmosphere

We introduce a microhollow cathode configuration with venturi gas flow to ambient air in order to obtain glow discharge at atmospheric pressure. Stable microhollow cathode discharge was formed in a 200 μ m diameter at 9 mA and the optimum value of gas velocity × diameter for hollow cathode effect was obtained in our system. In order to confirm hollow cathode effect, we measured the enhancement of E ∕ N strength for 200 μ m ( 0.31 m 2 ∕ s ) and 500 μ m ( 0.78 m 2 ∕ s ) air discharge at 8 mA under the velocity of 156 m ∕ s . As a result, an increase of 46.7% in E ∕ N strength of the discharge of 200 μ m hole was obtained compare to that of 500 μ m .