High-Sensitivity In-Situ Diagnosis of NO_2 Production and Removal in DBD Using Cavity Ring-Down Spectroscopy  

作　　者：吴兴伟 李聪 张辰飞 丁洪斌 

机构地区：[1]Key Laboratory of Materials Modification by Laser,Ion and Electron Beams,Chinese Ministry of Education,School of Physics and Optical Electronic Technology,Dalian University of Technology

出　　处：《Plasma Science and Technology》2014年第2期142-148,共7页等离子体科学和技术（英文版）

基　　金：supported by the National Magnetic Confinement Fusion Science Program of China(No.2013GB109005);National Natural Science Foundation of China(Nos.11175035,10875023);Chinesisch-Deutsches Forschungs Project(GZ768);the Fundamental Research Funds for the Central Universities(DUT12ZD(G)01);Mmlab Research Project of China(DP1051208)

摘　　要：A highly-sensitive in-situ diagnosis approach for nitrogen dioxide （NO2） has been developed in dielectric barrier discharge （DBD） based on pulsed cavity ring-down spectroscopy （CRDS）. Absorption bands of NO2 in a spectral region from 508 nm to 509 nm were used, and a detection limit of 17.5 ppb was achieved. At this level of sensitivity, the quantitative and real-time monitoring of the production and removal of NO2 are accomplished for the first time in the discharge region. By measuring the removal amount and rate at different NO2 initial number densities from 1.54 ×10^13 cm^-3 to 2.79 × 10^14 cm^-3, we determined the relationship between them and NO2 initial number densities. The removal amount linearly increases with the initial number density, while the removal rate increases logarithmically. At a lower initial number density, the removal rate is limited. By considering the chemical kinetic mechanism in plasma, a qualitative explanation for the above phenomena is proposed： the additional NO2 produced by discharge limits the removal rate, since the NO2 concentration is dominated by the competition between the forward reactions （production） and the reverse reactions （removal）.A highly-sensitive in-situ diagnosis approach for nitrogen dioxide （NO2） has been developed in dielectric barrier discharge （DBD） based on pulsed cavity ring-down spectroscopy （CRDS）. Absorption bands of NO2 in a spectral region from 508 nm to 509 nm were used, and a detection limit of 17.5 ppb was achieved. At this level of sensitivity, the quantitative and real-time monitoring of the production and removal of NO2 are accomplished for the first time in the discharge region. By measuring the removal amount and rate at different NO2 initial number densities from 1.54 ×10^13 cm^-3 to 2.79 × 10^14 cm^-3, we determined the relationship between them and NO2 initial number densities. The removal amount linearly increases with the initial number density, while the removal rate increases logarithmically. At a lower initial number density, the removal rate is limited. By considering the chemical kinetic mechanism in plasma, a qualitative explanation for the above phenomena is proposed： the additional NO2 produced by discharge limits the removal rate, since the NO2 concentration is dominated by the competition between the forward reactions （production） and the reverse reactions （removal）.

关 键 词：DBD CRDS NO2 production NO2 removal 

分 类 号：O433[机械工程—光学工程]