A diffuse plasma generated by bipolar nanosecond pulsed dielectric barrier discharge in nitrogen

摘要

In this study, a bipolar high-voltage pulse with 20 ns rising time is employed to generate diffuse dielectric barrier discharge plasma using wire-plate electrode configuration in nitrogen at atmospheric pressure. The gas temperature of the plasma is determined by comparing the experimental and the best fitted optical emission spectra of the second positive bands of N_2(C~3Π_u → B~3Π_g, 0-2) and the first negative bands of N_ 2~+ (B~2Σ_u~+ → X~2Σ_g~+, 0-0). The effects of the concentration of argon and oxygen on the emission intensities of N_2(C~3Π_u → B~3Π_g, 0-0, 337.1 nm), OH(A~2Σ → X~2Π, 0-0) and N_2~+ (B~2Σ_u~+ → X~2Σ_g~+, 0-0, 391.4 nm) are investigated. It is shown that the plasma gas temperature keeps almost constant with the pulse repetition rate and pulse peak voltage increasing. The emission intensities of N_2(C~3Π_u → B~3Π_g, 0-0, 337.1 nm), OH(A~2Σ → X~2Π, 0-0) and N_2~+ (B~2Σ_u~+ → X~2Σ_g~+, 0-0, 391.4 nm) rise with increasing the concentration of argon, but decrease with increasing the concentration of oxygen, and the influences of oxygen concentration on the emission intensities of N_2(C~3Π_u → B~3Π_g, 0-0, 337.1 nm) and OH (A~2Σ → X~2Π, 0-0) are more greater than that on the emission intensity of N_2~+ (B~2Σ_u~+ → X~2Σ_g~+, 0-0, 391.4 nm).