ラマン散乱法による大気圧窒素放電中の準安定励起分子N₂(A³Σ_u⁺)の検出

抄録

Raman scattering from metastable excited nitrogen molecules N₂(A³Σ_u⁺) created by an impulse discharge in nitrogen at atmospheric pressure was detected. A pulsed Nd:YAG laser of wavelength 266 nm was used as the light source, and Raman scattering from N₂(A³Σ_u⁺) at wavelength 277 nm was detected using an interference filter and photomultiplier tube. The filter had sufficient rejection of Rayleigh scattering of laser light at wavelength 266 nm and Raman scattering from ground state nitrogen molecules N₂(X¹Σ_g⁺) at wavelength 284 nm. The temporal variation of the signal intensity of Raman scattering from N₂(A³Σ_u⁺) was measured by transmitting the laser at different time delays relative to sparkover. Results showed that the signal intensity decayed with a time constant of about 200 μs.