吸气模式激光推进空气等离子体光谱

Laser-induced plasma spectroscopy on air-breathing mode

利用实验室自行研制的紫外预电离CO2激光器进行了激光等离子体实验,实验采用底面直径均为60mm,焦距分别为5 mm和10 mm的两种抛物面光船。介绍了激光等离子体光谱和明显的特征谱线,以及激光等离子体温度估计模型;分析了两种光船对激光等离子体的影响。实验表明:相同底面直径10 mm焦距光船产生的等离子体信号峰值和持续时间均略大于5 mm焦距光船;10 mm焦距光船产生的等离子体温度明显高于5 mm的,最大温度产生时间比5 mm光船要晚一些。

The experiment of laser-induced plasma using the UV-preionized CO2 laser made was discussed. Two cylinder flight vehicles with parabolic inner surface were used in this experiment, which have the same aperture diameter 60mm, and the focal length were 5 mm and 10 mm, respectively. The spectroscopy of laser-induced plasma, the distribution of characteristic lines, and method for calculating plasma temperature was introduced. Furthermore, the influence of flight shape on the laser plasma was analyzed. The results show that, with the same aperture diameter, the maxium intensity of laser plasma with longer focal length flight was higher and the evolution time was longer as well as the maxium plasma temperature was higher. Furthermore the time reaching the maxium temperature was shorter than that with shorter focal length.