为了深入研究激光诱导等离子体的物理特性，提高激光诱导击穿光谱(LIBS)技术的测量精度和可靠性，对激光诱导等离子体的时间演化过程进行了实验研究。采用ICCD相机对激光诱导铝合金等离子体进行快速成像，发现激光诱导铝合金等离子体的寿命大约为30 μs，等离子体呈现明显的分层结构，并且不同区域的面积和温度在等离子体的时间演化过程中呈现不同的特征。通过玻尔兹曼斜线法和Stark展宽法计算了铝合金等离子体电子温度和电子数密度的时间演化规律。实验结果表明，等离子体的电子激发温度在6000 K~9000 K之间，且前3 μs下降较快；等离子体电子数密度为1017 cm-3量级，并随ICCD探测延迟时间缓慢降低。等离子体电子温度和电子数密度的时间演化规律与ICCD相机快速成像结果一致。

In order to further investigate the physical properties of the laser-induced plasma and improve the measurement precision and reliability of the laser-induced breakdown spectroscopy (LIBS) technology, the time evolution process of the laser-induced plasma is studied experimentally. Through fast imaging of the laser-induced aluminum alloy plasma using the ICCD camera, it is found that the lifetime of the laser-induced aluminum alloy plasma is about 30 μs, the plasma has an obvious hierarchical structure, and furthermore the areas and temperatures of different regions present different characteristics during the time evolution process. The time evolution process laws of the electron temperature and the electron number density are obtained using the Boltzmann plot method and Stark broadening of line, respectively. The results show that the electron excitation temperature of the plasma ranges from 6000 K to 9000 K, and it decreases rapidly in the first 3 μs. Besides the electron number density is in the order of 1017 cm-3, it decreases slowly with ICCD detection delay time. The time evolution laws of electron temperature and the electron number density are in agreement with that of the fast imaging by the ICCD camera.