Spectrum-analysis study of parameters associated with laser-induced air breakdown plasma

The electron temperature and density of air plasma hold important meanings for researching the process of laser-induced air breakdown plasma. In this paper, a TEM 00 Q Nd:YAG laser with a wavelength of 1064 nm is used. When the laser is focused on the atmosphere, it will produce a plasma flash. The spectrum of the resulting air breakdown plasma is collected using a Avantes-ULS3648 spectrometer with nine separate channels. Changes in electron temperature and density of the plasma at different delay times are studied by spectral analysis. According to the spectrum of a given element with different peak positions, the electron temperature of the plasma can be obtained by employing the intensity comparative method, and the electron density of the plasma can be obtained by invoking the Stark broadening method. It was found that both the temperature and density of the air plasma decrease with increasing of the delay time. Such results maintain a high degree scientific significance for improving the accuracy and precision of on-line measurements in the atmospheric environment.