Collisional Quenching Rate Coefficient of N_2 (A~3 Σ_u~+) by o-xylene and Influence of Xylene By-products Attached to Electrode Surface

摘要

Determination of the effective lifetime of N_2(A~3Σ_u~+) in N_2/o-xylene (C_8H_(10)) mixtures is carried out by the waveform analysis of the transient current after turning off the UV light in the Townsend discharge region. The collisional quenching rate coefficient of N_2(A~3Σ_u~+) by o-xylene is determined together with the diffusion coefficient of N_2(A~3Σ_u~+), and the reflection coefficient on electrode surface of N_2 (A~3Σ_u~+). The obtained collisional quenching rate coefficient of N_2(A~3Σ_u~+) by o-xylene is (2.3±0.3)×10~(-9) cm~3/s. The value is a high than that of m-xylene measured previously. In the repeated measurements of the current-voltage curves, it is found that curves shift to the high E/p_0 side gradually with time as well as the case of m-xylene, and the effect of current prevention phenomena in o-xylene is larger than the case of m-xylene. In addition, the phenomenon that it is impossible to measure the transient current experienced in N_2/m-xylene mixtures is not observed.