闪电放电通道的辐射演化特性

用无狭缝红外光谱仪获得了山东地区云对地闪电回击过程的近红外光谱,并与可见光波长范围的闪电回击光谱进行了对比分析.根据近红外光谱的结构特征,讨论了闪电通道等离子体的光谱辐射顺序以及不同波段连续光谱的主要辐射机制,研究得出：可见光谱主要是闪电回击初期和发展阶段的辐射|近红外光谱主要是闪电发展后期的辐射|可见波段的连续光谱主要来自韧致辐射的贡献,而红外部分的连续光谱主要来自复合辐射的贡献.由分析结果推断：闪电通道等离子体的复合过程是闪电产生O3、NOX的主要途径,复合过程中的氧吸附作用和去吸附过程是近红外光谱中氧原子谱线增多的重要原因,也是OI 777.4 nm相对强度比较大的主要原因.

Radiation Evolution Characteristic of Lightning Discharge Channel

Near-infrared spectra of lightning return strokes are obtained by Slit-less infrared spectrograph in Shandong region.Compared with the visible spectrum of lightning return strokes,the radiation order of lighting plasma is analyzed,and the main radiation mechanism of continuum spectra in the two wavelength range are also discussed.The obtained results show that:the visible spectrum of lightning is mainly radiation from early stages and development of lightning,and the line spectra of ionizing nitrogen and oxygen is the main spectra of the separation spectrum|the near-infrared spectrum is mainly radiation from the latter of the lightning, and the line spectra of neutral nitrogen and oxygen atoms is the main spectra of the separation spectrum|the visible spectral band is mainly from bremsstrahlung contribution and the infrared part of the continuous spectrum is mainly from the recombination radiation|loss of a photon for the free electronic of high-temperature and other energy particle collisions of the lightning plasma is the main course of bremsstrahlung process,there are a lot of free e-collision,the lightning channel gathered in a large number of neutral atoms,molecules,electronics,and with the positively charged ions (including N++,N+,N*,N,O++,O+,O*,O particles,etc.),thus forming a typical plasma channel|atmospheric ions and free electrons of the dissociation process and the positive ions and negative ion radiation process is the direct radiation of the two main ways.It is deduced from the results that the recombination in lightning plasma is the main process for lightning producing O3 and NOX,the sorption and desorption of oxygen during the recombination may be the main reason for increased lines of oxygen atom in near-infrared spectra,and also for relative strength of OI 777.4 nm that is larger than normal.