A comparative study on the spectral characteristics of nanosecond pulsed discharges in atmospheric He and a He+2.3%H_(2)O mixture

作     者：陈传杰 彭东宇 刘博通 张婷琳 钱沐杨 周锋 王如刚 Chuanjie CHEN;Dongyu PENG;Botong LIU;Tinglin ZHANG;Muyang QIAN;Feng ZHOU;Rugang WANG

作者机构：School of Information EngineeringYancheng Institute of TechnologyYancheng 224051People’s Republic of China School of Physics and Materials ScienceNanchang UniversityNanchang 330031People’s Republic of China 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2024年第26卷第6期

页      面：22-30页

核心收录：

学科分类：080901[工学-物理电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：the funding provided by National Natural Science Foundation of China (No.12065019) Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No. 20KJB140025) the Open Fund of the Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No. JBGS032) the Scientific Research Project for the Introduction Talent of Yancheng Institute of Technology(Nos. XJR2020031 and XJR2021069) 

主　　题：nanosecond repetitively pulsed discharge helium and water vapor optical emission spectroscopy atmospheric pressure micro-discharge kinetics 

摘      要：Nanosecond pulsed discharges at atmospheric pressure in a pin-to-pin electrode configuration are well reproducible in time and space, which is beneficial to the fundamentals and applications of low-temperature plasmas. In this experiment, the discharges in helium(He) and He with 2.3%water vapor(H_(2)O) are driven by a series of 10 ns overvoltage pulses(~13 k V). Special attention is paid to the spectral characteristics obtained in the center of discharges by time-resolved optical emission spectroscopy. It is found that in helium, the emission of atomic and molecular helium during the afterglow is more intense than that in the active discharge, while in the He+2.3%H_(2)O mixture, helium emission is only observed during the discharge pulse and the molecular helium emission disappears. In addition, the emissions of OH(A-X) and Hα present similar behavior that increases sharply during the falling edge of the voltage pulse as the electrons cool down rapidly. The gas temperature is set to remain low at 540 K by fitting the OH(A-X) band. A comparative study on the emission of radiative species(He, He_(2), OH and H)is performed between these two discharge cases to derive their main production mechanisms. In both cases, the dominant primary ion is He^(+) at the onset of discharges, but their He^(+) charge transfer processes are quite different. Based on these experimental data and a qualitative discussion on the discharge kinetics, with regard to the present discharge conditions, it is shown that the electron-assisted three-body recombination processes appear to be the significant sources of radiative OH and H species in high-density plasmas.