闪电首次回击过程的光谱特性

Spectral Properties of the Lightning Return Stroke

用无狭缝摄谱仪,拍摄了4次云对地闪电首次回击过程390～660nm波长范围的光谱,并将原子结构的理论应用于闪电光谱的研究,用多组态Dirac-Fock方法,系统考虑相对论效应、电子关联、弛豫效应等重要贡献,对光谱的精细结构进行了计算,给出了谱线的波长、振子强度以及相应的上能级激发能量。通过与试验观测谱线的比较分析发现,大多数谱线对应的上激发能在23ev左右。首次回击过程中,闪电通道内NII离子的密度最大,并且大多数处于n=3的激发态。

The spectra in 390～660 nm regions from the first return strokes between cloud and ground have been obtained by a slit\|less spectrograph. Appling the atomic structure theory to the research work on lightning spectra, wavelength, oscillator strengths and excited energy of upper levels have been calculated for the transitions of NII ions related to lightning discharges. Large\|scale multi\|configuration Dirac\|Fock wave functions are applied to include the most important effects of relativity, correlation, and relaxation within the same (computational) model. Comparing with the calculated results of experimental spectra show that, during return stroke, the corresponding upper excited energies for most lines are around 23ev. NII is the most abundant ion among the channel plasma, and mainly in excited state of \%n\%=3.