利用浓度调制光谱技术, 测量了玻璃管中放电频率20 kHz时N2的介质阻挡放电光谱。实验记录了N2的C3∏u-B3∏g 357. 7nm和N+2的B2∑+u-X2∑+g 391.4 nm的跃迁谱线光谱强度随不同电压和气体压强变化规律。实验数据显示, 保持气体压强p=130 Pa不变, 在电压较低时, 光谱强度随电压增长较快, 在电压较高时, 光谱强度增长较慢; 保持放电电压U=6.4 kV不变, 光谱强度随气压增长逐渐变小。根据电子和分子碰撞激发函数和电离函数, 建立光强随放电参数变化的物理理论模型和公式, 并对实验数据进行数学拟合, 拟合曲线与实验结果符合较好, 相关系数R>0.9。进一步明确了等离子体发射光谱强度随不同电压和气体压强变化的机理。

N2 spectral in glass capillary by dielectrical barrier discharge at discharge frequency of 20 kHz are measured via concentration modulation spectroscopy. The spectral lines at 357.7 nm of N2 C3∏u-B3∏g and at 391.4 nm N+2 B2∑+u-X2∑+g are recorded to study the effect of discharge voltage and gas pressure. The measurement results show that the intensity increases rapidly with discharge voltage at a lower voltage range, but the speed slows at the higher voltage range, for constant gas pressure of 130 Pa; and the intensity increases backwardly with gas pressure at constant discharge voltage of 6.4 kV. Furthermore, a theoretical model is proposed according to electronic excitation function and ionization function, which can basically interpret the relation between spectral intensity and discharge parameters, fit the experimental data well, and the correlation coefficient is over 0.9. The mechanism of the dependence of the emission spectral intensity on discharge voltage and gas pressure in the plasma discharge was revealed further.