The absolute density of metastable N_2 (A~3Σ_u~+), the rate constant of the reactions of N_2 (A~3Σ_u~+) with various molecules and one-dimensional distribution of that excited nitrogen molecules are observed after the pulsed positive corona discharge in various gasses of 1 atmospheric pressure by using the laser-induced fluorescence (LIF). The N_2 (A~3Σ_u~+, v=0) state is excited to N_2(B, v"=4) state by the laser irradiation. That excited state drops to (A, v"=1) state emitting 676 nm light as the fluorescence. The discharge occurs from needle to plane electrode with the gap distance of 12 mm. When discharge voltage is 21.5 kV, the absolute density N_2 (A~3Σ_u~+) near the needle point just after the discharge is estimated to 10~(14) cm~(-3) by that fluorescence intensity. The observed one-dimensional distribution of the N_2 (A~3Σ_u~+) suggests that is mostly generated in the primary streamer channel.
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