Time-resolved measurements of NO2 concentration in pulsed discharges by high-sensitivity cavity ring-down spectroscopy  

作　　者：吴兴伟 李聪 冯春雷 王奇 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, Dalian University of Technology, Dalian 116024, People's Republic ofChina

出　　处：《Plasma Science and Technology》2017年第5期80-84,共5页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(Nos.11175035,11405022,11475039,11605023);the National Magnetic Confinement Fusion Science Program of China(No.2013GB109005);Chinesisch-Deutsches Forschungsprojekt(No.GZ768);the Fundamental Research Funds for the Central Universities(Nos.DUT14ZD(G)04,DUT15RC(3)072,DUT15TD44,DUT16TD13);China Postdoctoral Science Foundation(No.2016M591423)

摘　　要：To describe the complex kinetics of formation and destruction mechanism of nitrogen dioxide（NO2）, there is an increasing demand for real-time and in situ analysis of NO2 in the discharge region. Pulsed cavity ring-down spectroscopy（CRDS） provides an excellent diagnostic approach. In the present paper, CRDS has been applied in situ for time evolution measurement of NO2 concentration which is rarely investigated in gas discharges. In pulsed direct current discharge of NO2/Ar mixture at a pressure of 500 Pa, a peak voltage of -1300 V and a frequency of 30 Hz, for higher initial NO2 concentration（3.05×10^（14）cm^（-3）, 8.88×10^（13）cm^（-3））,the NO2 concentration sharply decreases at the beginning of the discharge afterglow and then becomes almost constant, and the pace of decline increases with pulse duration; however, for lower initial NO2 concentration of 1.69×10^（13）cm^（-3）, the NO2 concentration also decreases at the beginning of the discharge afterglow for 200 ns and 1 μs pulse durations, while it slightly increases and then declines for 2 μs pulse duration. Thus, the removal of low-level NO2 could not be promoted by a higher mean energy input.To describe the complex kinetics of formation and destruction mechanism of nitrogen dioxide（NO2）, there is an increasing demand for real-time and in situ analysis of NO2 in the discharge region. Pulsed cavity ring-down spectroscopy（CRDS） provides an excellent diagnostic approach. In the present paper, CRDS has been applied in situ for time evolution measurement of NO2 concentration which is rarely investigated in gas discharges. In pulsed direct current discharge of NO2/Ar mixture at a pressure of 500 Pa, a peak voltage of -1300 V and a frequency of 30 Hz, for higher initial NO2 concentration（3.05×10^（14）cm^（-3）, 8.88×10^（13）cm^（-3））,the NO2 concentration sharply decreases at the beginning of the discharge afterglow and then becomes almost constant, and the pace of decline increases with pulse duration; however, for lower initial NO2 concentration of 1.69×10^（13）cm^（-3）, the NO2 concentration also decreases at the beginning of the discharge afterglow for 200 ns and 1 μs pulse durations, while it slightly increases and then declines for 2 μs pulse duration. Thus, the removal of low-level NO2 could not be promoted by a higher mean energy input.

关 键 词：CRDS ns-pulsed discharge time evolution of NO2 concentration 

分 类 号：O461[理学—电子物理学]