利用近红外波段光谱研究闪电回击通道温度的演化特性

Study on Evolution of Lightning Return Stroke Channel Temperature by Near-Infrared Spectroscopy

依据3个闪电回击过程的时间分辨光谱，采用不同的方法计算闪电核心电流通道温度及外围发光通道温度，研究了回击电流衰减过程中通道温度随时间的演化特性。结果表明，核心电流通道温度比外围发光通道温度高4000-5000K。在峰值电流之后，相比于电流的变化，通道温度的衰减更为缓慢。峰值电流之后约400μs时，通道温度仍维持在20000K左右，如此长时间的高温导致的热效应是许多闪电灾害的主要根源。

According to the time-resolved spectra of three lightning return stroke processes, the temperature of the arc core channel and the peripheral luminous channel is calculated with different methods, and the evolution of channel temperature with time in the process of current decay is studied. The results show that the temperature of the core current channel is about 4000-5000 K higher than that of the peripheral luminous channel. The decrease of the channel temperature with time is very slow compared with that of the discharge current after the peak value occurs. Up to about 400 ,us after the peak current occurs, the channel temperature still stays at about 20000 K, and the heat effect resulting from high temperature for such a long time is the main source of most lightning disasters.