利用介质阻挡放电装置,在低气压空气中得到了均匀放电,并采用光谱法,研究了放电等离子体温度的空间均匀性。实验采集了氮分子光谱,采用氮分子第二正带系C3Πu→B3Πg计算振动温度;采用氮分子离子第一负带系B2Σu+→X2Σg+计算转动温度(气体温度)。实验发现,振动温度随电压增加而减小,而转动温度随电压增加而增大。等离子体振动温度和转动温度在空间上的涨落幅度均随电压增加而减小,说明放电的均匀性随电压增加而逐步加强。上述结果对于空气均匀放电等离子体在材料处理应用具有重要意义。
In the present work,a uniform discharge in low-pressure air was obtained by a dielectric barrier discharge device.The spatial homogeneity of the plasma temperature was studied by optical emission spectrum.The vibrational temperature was calculated by second positive band C3Πu→B3Πg and the rotational temperature(gas temperature) was calculated by N+2 first negative band B2Σ+u→X2Σ+g.It was found that the vibrational temperature decreases with the voltage increasing,while the rotational temperature increases.In addition,the fluctuation amplitudes of vibrational and rotational temperature of the plasma along diameter of the discharge area decrease with the voltage increasing,which indicates that the homogeneity of the plasma increases with the voltage increasing.These results are of great significance to the application of uniform discharge obtained in air dielectric barrier discharge for material processing.