压强对空气/氩气介质阻挡放电中等离子体温度的影响

Influence of Pressure on Plasma Temperature in Air/Argon Dielecteic Barrier Discharge

使用水电极介质阻挡放电装置,在氩气和空气的混合气体放电中,利用发射光谱法,研究了电子激发温度和分子振动温度随气体压强的变化关系。通过氩原子763.51nm(2P6→1S5)和772.42nm(2P6→1S3)两条谱线强度比法计算电子激发温度;通过氮分子第二正带系(C3Πu→B3Πg)的发射谱线计算氮分子的振动温度;对氮分子离子391.4nm和激发态的氮分子337.1nm两条发射谱线的相对强度进行了测量,以进一步研究电子能量的变化。实验表明,随着压强从20kPa增大到60kPa,电子激发温度减小,分子振动温度减小,氮分子离子谱线与激发态的氮分子谱线强度之比减小。

Electron excitation temperature and molecule vibrational temperature in argon/air dielectric barrier discharge （DBD） at different gas pressure with water electrodes were studied by using optical emission spectra. The spectral lines of Ar Ⅰ 763.51 nm（2P6→1S5） and ArⅠ 772.42 nm（2P2→1S3） were chosen to calculate electron excitation temperature by the relative intensity ratio method. The emission spectra of nitrogen band of second positive system （C^3Πu→B^3Πg） were measured at the same time. The molecule vibration temperature was estimated by the emission intensities of different bands with Δν=-1, Δν=-2, and Δν=-3 in nitrogen band of second positive system, using Boltzmann’s plot method. In addition, the relative line intensities of nitrogen （0-0） band of first negative system at 391.4 nm and （0-0） band of second positive system at 337.1 nm were also measured to study the variation of electron energy. It was found that the electron excitation temperature decreased from 4 700 to 3 300 K and the molecule vibrational temperature decreased from 3 200 to 2 900 K with increasing gas pressure from 20 to 60 kPa. Besides, the ratio of I（N＋2）/I（N2） also decreased with pressure increasing from 20 to 60 kPa, indicating that the average electron energy decreases with the gas pressure increasing. These results are of great importance to the study of plasma dynamics of dielectric barrier discharge and also to the underlying industrial applications.