Measurement of N-2(A (3)Sigma(+)(u)) metastable in N-2 pulsed positive corona discharge with trace amounts of additives

摘要

The density of N-2(A(3)Sigma(+)(u)) metastable is measured in various gases (N-2/O-2, N-2/NO, N-2/NO2, N-2/H2O, N-2/CO) after pulsed positive corona discharge using time-resolved laser-induced fluorescence (LIF) under atmospheric pressure. The N-2(A(3)Sigma(+)(u)) density in N-2/O-2(0.25%) is uniformly distributed along the axis of the discharge gap (point-to-plane, 12 mm). This result indicates that N-2(A(3)Sigma(+)(u)) is mostly generated in the primary streamer channels. The absolute N-2(A(3) Sigma(+)(u)) density is measured by calibrating the LIF signal intensity. When the discharge voltage is 21.5 kV, the N-2(A(3)Sigma(+)(u)) density immediately after the discharge pulse is estimated to be (2-3) x 10(13) cm(-3). The reaction rate constants of N-2(A(3)Sigma(+)(u)) with O-2, NO, NO2, H2O and CO are roughly estimated using the decay rate of N-2(A(3)Sigma(+)(u)) density after the discharge pulse, and are compared with reference values. N-2(A(3)Sigma(+)(u)) production is increased approximately twofold when hundreds of ppm of O-2, NO or NO2 molecules are added to N-2.