自持体放电的发射光谱研究

自持体放电又称大气压脉冲放电或脉冲辉光放电,是一种利用微秒-亚微秒量级脉冲在大气压下获得大体积等离子体的放电形式。为了测量自持体放电过程中气体温度的演化,采用光谱拟合的方法,对氮分子第二正带光谱进行了理论分析。并对两套横向激励大气压(TEA)气体激光器放电系统(准分子放电腔快放电系统,TEA CO2激光器放电腔慢放电系统)的等离子体时域分辨分子光谱进行了测量,并拟合了气体转动温度,取得了两种不同放电结构放电过程中气体温度演化的数据。结果表明,准分子放电腔快放电过程中总的能量注入密度为1.3105J/m3时,温度升高92K,TEA CO2激光器放电腔慢放电过程中总的能量注入密度为7104J/m3时,温度升高约50K,两套系统温度升高比对应于总的注入能量密度比。这一结果对研究自持体放电机理提高放电稳定性是有帮助的。

Study on emission spectrum of self-sustained volume discharge

In order to measure the evolution of gas temperature during self-sustained volume discharge, the second positive spectra of nitrogen was analyzed using fitting spectra method. Plasma time-domain resolution molecular spectra of two transversely excited atmospheric(TEA)gas laser discharge systems (excimer laser fast discharge system and TEA CO2 laser slow discharge system) were measured. Gas rotational temperature was fitted to obtain the data of gas temperature evolution of two discharge structures. The results show that the rising temperature is 92K while the total of inject energy density is 1.3105 J/m3 of excimer laser fast discharge system and the rising temperature is 50K while the total of inject energy density is 7104 J/m3 of TEA CO2 laser slow discharge system. The ratio of the rising temperature of these two systems is proportional to the raio of the inject energy density of these two systems. These results are helpful to study self-sustained volume discharge mechanism and improve discharge stability.