发射光谱研究氩气/空气混合气体介质阻挡放电能量传递过程

Study on Energy Transfer in Argon/Air in Dielectric Barrier Discharge by Optical Emission Spectra

使用水电极介质阻挡放电装置,对比氩气与氩气/少量空气的混合气体以及空气与空气/少量氩气的混合气体放电的发射光谱,研究了氩气与空气相混合时气体放电中的能量传递过程。实验发现,当氩气中加入少量的空气时,氩原子谱线均变弱,说明空气中的氮分子对氩原子的各激发态具有猝灭作用。并且随着空气含量的增加,各谱线变弱的速率不同。越是与氮分子的激发电位接近的氩原子的激发态被猝灭的作用越明显。另一方面,当空气中加入少量氩气时,发现氮分子第二正带系和氮分子离子第一负带系的谱线均被增强。说明在空气/少量氩气放电中,氮分子的激发由于亚稳态氩原子的潘宁激发传能而增强。因此在氩气/空气混合气体放电中,气体成分及比例影响放电的发光特性和能量传输特性。

The energy transfer in dielectric barrier discharge in argon/air mixture in a device with water electrodes was investigated by comparing the optical emission spectra in pure argon,argon/air mixture and air.It was observed that the intensities of argon spectral lines in argon/air discharge are all lower than that in argon discharge,which indicates that the nitrogen in air has a quenching effect on the argon excited states.It was found that the decreasing rate of intensity of spectral lines with increasing the air concentration is different.The intensity of ArI 763.51 nm decreases fastest,the ArⅠ 772.42 nm and ArⅠ 696.54 nm take second place,while the ArI 750.39 nm decreases slowest.Comparing the excitation energy of argon excited state with the excitation energy of nitrogen molecule,the authors found that the smaller the difference between the excitation energy of argon excited state and the excitation energy of nitrogen molecule,the faster the spectral line decreases,implying the stronger the energy transfer.In addition,the additional argon in air makes the emission intensities of nitrogen band of second positive system and band of first negative system increase,which indicates that the excitation of nitrogen is enhanced by the energy transfer from argon through Penning excitation involving argon metastable states.In other words,the component and ratio of gas in the gas mixture influence the optical characteristic and energy transfer peculiarity in the mixed gas discharge.The optical emission spectra measurement as a useful plasma diagnostic tool has been successfully used in the study of energy transfer in the mixed gas discharge,and the results provide a reasonable reference for the underlying industrial applications of different species discharge.