介质势垒放电(DBD)等离子体中NO荧光发射谱研究

利用介质阻挡放电 (DBD)等离子体技术对大气污染物NO分子进行了光谱研究 ,得到了低气压条件下放电等离子体在 2 1 0～ 2 80nm光谱范围内的荧光发射谱。该谱明显的表现为双峰结构 ,谱线均成对出现 ,强度分布符合Frank Condon原理 ,且最大峰值位置出现在 2 36nm处 ,将该组谱线归属为NO分子的A2 ΣA →X2 Π1 / 2 ,2 / 3 跃迁。荧光产生过程为 :基态NO分子与高能电子发生非弹性碰撞被激发至激发态A2 Σ 后自发跃迁回基态同时辐射出荧光。通过测量等离子体中NO分子和N2 分子 337nm谱线强度随时间的变化关系 ,初步证实了放电等离子体中存在的NO分子的分解机制为 :e NO→N O e,N NO→N2 O ,O NO→NO2 hν。

The Fluorescence Emission Spectrum of NO in Dielectric Barrier Discharge (DBD) Plasma

Dielectric barrier discharge was used to study the NO molecules of the atmosphere pollution, and the fluorescence emission spectrum in the range of 210-280 nm at low pressure was obtained in this plasma. The spectrum shows obviously the structure of double apices, whose intensity distribution in accord with Frank-Condon principle and the maximum lies at 236 nm. The main lines are attributed to the A 2 sigma+ -->X 2 pi 1/2, 2/3 transition. The produce of fluorescence can be described as: NO molecules at the ground state are impacted to the A 2 sigma+ excited state by fast electrons, and then transit to the ground state radiating fluorescence. By measuring the relation between discharge time and emission intensity of NO and N2 molecules in the discharge plasma, we demonstrated the dissociation mechanism of NO in the discharge period, which can be interpreted as: e* + NO-->N + O + e, N + NO-->N2 + O, O + NO-->NO2 + h nu.