为了深入了解大气压下Ar等离子体射流的产生机理和内部电子的状态, 对Ar等离子体射流进行了发射光谱诊断, 以玻尔兹曼斜率法对电子激发温度进行测算, 利用发射光谱的连续谱绝对强度法测算出电子密度。通过设计一种可调节气压的金属针-环型介质阻挡放电装置, 研究了氩气压和放电功率对Ar等离子体射流的电子激发温度和电子密度的影响。结果表明, 随着气压从6 kPa升高到16 kPa, 电子激发温度从0.83 eV下降到0.68 eV, 电子密度从4.45×1022 m-3减小到0.44×1022 m-3(波长648.06 nm), 且随着放电功率从0.177 5 W增大到1.792 6 W, 电子激发温度从0.82 eV升高到5.14 eV, 电子密度从0.27×1022 m-3增大到4.61×1022 m-3, 而且电子密度较低时, 电子激发温度的变化更明显。由此得出结论, 氩气压和放电功率对电子激发温度不仅有直接影响, 还有通过电子密度变化导致的间接影响, 电子密度较低时, 氩气压和放电功率对电子激发温度的影响会相对更大一些。同时, 选用两个波长计算的电子密度结果很接近, 验证了诊断结果的准确性。

In order to deeply understand the mechanism of Ar plasma jet under atmospheric pressure and the state of internal electron, the emission spectrum diagnosis of Ar plasma jet was carried out. The electron excitation temperature was calculated by Boltzmann slope method, and the electron density was calculated by the continuous spectral absolute intensity method of emission spectrum. The effect of argon pressure and discharge power on electron excitation temperature and electron density of Ar plasma jet was studied by designing a metal needle-ring dielectric barrier discharge device with adjustable air pressure. The results show that with increased pressure from 6 kPa to 16 kPa, electron excitation temperature reduced from 0.83 eV to 0.68 eV, electron density from 4.45×1022m－3 to 0.44×1022 m-3, and with increased discharge power from 0.177 5 W to 1.792 6 W, electron excitation temperature increased from 0.82 eV to 5.14 eV, electron density increased from 0.27×1022 m-3 to 4.61×1022 m-3, and when the electron density is lower, electron excitation temperature change is more obvious. It is concluded that argon pressure and discharge power not only have direct effects on the electron excitation temperature, but also have indirect effects caused by the change of electron density. When the electron density is low, the influence of argon pressure and discharge power on the electron excitation temperature will be relatively greater. At the same time, the results of electron density calculated by using two wavelengths are very close, which verifies the accuracy of the diagnosis results.