激光诱导空气等离子体光谱时间演化特性的研究

利用能量为150mJ和500mJ的激光击穿空气获得空气等离子体,依据光谱信息,计算得到等离子体电子温度,密度,并探讨了其时间演化特性,证实了在此过程中,复合相比电离居于主导地位.同时,结果表明:随着延迟时间的增加,谱线强度在300ns内迅速减小,之后缓慢减小;电子密度和谱线强度的变化规律基本一致;电子温度的衰减近似呈现指数拟合线型,并且激光能量越高,电子温度的衰减越慢.

The temporal evolution study of laser induced air plasma spectra

The laser induced air plasmas were obtained by the laser energy 150 mJ and 500 mJ, respectively. According to the information of spectra, the electron density and temperature were calculated, and then the properties of their temporal evolution were discussed. It is confirmed that the recombination is dominant in the process. Meanwhile, the results show that with the time increasing, the intensity of spectral line decreases quickly within 300 ns, then decreases slowly. The point is in good agreement with the variation of electron density. The attenuation of temperature is close to the linear fitting, and the higher the laser energy, the slower the attenuation of the temperature.