Spectroscopic diagnosis of plasma in atmospheric pressure negative pulsed gasliquid discharge with nozzle-cylinder electrode

The plasma characteristics of a gas-liquid phase discharge reactor were investigated by optical and electrical methods.The nozzle-cylinder electrode in the discharge reactor was supplied witha negative nanosecond pulsed generator.The optical emission spectrum diagnosis revealed that OH(A~2∑~+?→?X~2Π,306–309 nm),N~3_2(CΠ→B~3Π_g,337 nm),O(3p~5p→3s~5s~0,777.2 nm)and O(3p~3p→3s~3s~0,844.6 nm)were produced in the discharge plasma channels.The electron temperature(T_e)was calculated from the emission relative intensity ratio between the atomic O 777.2 nm and 844.6 nm,and it increased with the applied voltage and the pulsed frequency and fell within the range of 0.5–0.8 e V.The gas temperature(T_g)that was measured by Lifbase was in a range from 400 K to 600 K.