激光光解NO_2产物NO(X^2∏)的REMPI离子谱的标识与研究

Study and identification of NO(X^2∏) REMPI in spectrum

利用Nd:YAG激光器三倍频、输出波长为=355nm的激光光解NO2分子,可产生NO分子,将NO分子通过共振增强多光子电离(REMPIresonanceenhancedmultiphotoionization)及飞行时间(TOFtimeofflight)质谱技术,获得振转态分辨的NO(X2∏,υ″J″)离子谱NOγ(0,0),γ(0,1),γ(1,1)。通过理论计算,可将NO离子带的P、R、Q支线进行标识。NO分子的离子信号强度与UV电离激光能量(λ≈226nm)之间关系能用二次方曲线很好拟合。它表明NO分子是通过(1+1)双光子吸收而电离。这些结果对NO分子的电离动力学提供了有益的信息。

The ion spectrum of the NO(X^2∏)γ(0,0),γ(0,1)and γ(1,1) bands from the dissociation of NO_2 at laser wavelength λ=355 nm has been investigated using resonance enhanced multiphoton ionization (REMPI) and time of flight (TOF) mass spectrometer technique. The vibrotation state resolution ion spectrum of the NO(X^2∏, ν″, J″) from NO(A^2∑^+,ν′=0,1,J′←X^2∏,ν″=0,1,J″)transition is obtained. A identification of NO(X^2∏) REMPI ion spectrum γ(0,0) bands is presented by the theoretical calculation. The relation between ion signal intensity for NO and the energy of UV ionization laser (λ≈226 nm) can be well simulated with second proportional curve, it shows that NO(X^2∏) is ionized by (1+1) multiphoton absorption process. These results are very useful information for NO ionization dynamics.