常压射流等离子体发射光谱研究

Spectral Diagnosis of Plasma Jet at Atmospheric Pressure

使用改进介质阻挡放电装置生成常压射流等离子体,采用光纤光栅光谱仪在300-1000 nm范围记录了不同放电电压的氩气发射光谱,并比较了空气和氩气常压介质阻挡放电等离子体发射光谱,分析发现氩气发射光谱中的谱线都是氩原子的发射谱线,表明常压射流装置产生的等离子体全部为氩等离子体,而无其他空气成分参与放电。为测量电子激发温度,选用相距较近的763.51和772.42 nm两条光谱线对电子温度进行分析,结果表明电子激发温度的范围在0.1-0.3 eV,而且它还随着放电电压的增加而增加。初步使用“红外测温仪”测量被处理材料表面温度,结果发现材料表面的温度也随着放电电压的增加而增加,范围在50-100℃,材料表面温度的变化趋势可以近似表征等离子体宏观温度变化趋势。通过分析常压射流等离子体的温度特性,探讨了常压射流等离子体温度对材料改性研究的意义。

A new approach to surface modification of materials using dielectric barrier discharge（DBD） plasma jet at atmospheric pressure is presented in the present paper.The emission spectral lines of argon plasma jet at atmospheric pressure were recorded by the grating spectrograph HR2000 and computer software.The argon plasma emission spectra,ranging from 300nm to 1000nm,were measured at different applied voltage.Compared to air plasma emission spectra under the same circumstance,it is shown that all of the spectral lines are attributed to neutral argon atoms.The spectral lines 763.51 and 772.42 nm were chosen to estimate the electron excitation temperature.The purpose of the study is to research the relationship between the applied voltage and temperature to control the process of materials＇ surface modification promptly.The results show that electron excitation temperature is in the range of 0.1-0.5 eV and increases with increasing applied voltage.In the process of surface modification under the plasma jet,the infrared radiation thermometer was used to measure the material surface temperature under the plasma jet.The results show that the material surface temperature is in the range of 50-100 ℃ and it also increases with increasing applied voltage.Because the material surface was under the plasma jet and its temperature was decided by the plasma,and the material surface temperature increased with increasing the macro-temperature of plasma jet,the relationship between the surface temperature and applied voltage indicates the relationship between the macro-temperature of the plasma jet and the applied voltage approximately.The experimental results indicate that DBD plasma jet at atmospheric pressure is a new approach to improving the quality of materials＇ surface modification,and spectral diagnosis has proved to be a kind of workable method by choosing suitable applied voltage.