Investigation on the characteristics of an atmospheric-pressure microplasma plume confined inside a long capillary tube

作     者：Shuqun WU Fei WU Xueyuan LIU Wen CHEN Chang LIU Chaohai ZHANG 吴淑群;武菲;刘雪原;陈文;刘畅;张潮海

作者机构：Center for More Electric Aircraft Power SystemCollege of Automation EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016People＇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：2018年第20卷第10期

页      面：90-97页

核心收录：

学科分类：07[理学] 070204[理学-等离子体物理] 0702[理学-物理学] 

基　　金：partially supported by National Natural Science Foundation of China (No. 51607090) the Natural Science Foundation of Jiangsu Province (No. BK20160796) the Delta Research and Educational Foundation (No. DREG2017008) Fundamental Research Funds for the Central Universities (No. XCA17003–03) financial support from the China Scholarship Council 

主　　题：microplasma atmospheric pressure plasma non-thermal plasma microdischarge 

摘      要：An atmospheric-pressure microplasma plume of diameter 10 μm is generated inside a long tube. The length of the microplasma plume reaches as much as 2 cm. First, with the assistance of an air dielectric barrier discharge （DBD）, the ignition voltage of the microplasma decreases from 40 kV to 23.6 kV. Second, although the current density reaches as high as （1.2-7.6）× 10 4A cm-2, comparable to the current density in transient spark discharge, the microplasma plume is nonthermal. Third, it is interesting to observe that the amplitude of the discharge current in a positive cycle of applied voltage is much lower than that in a negative cycle of applied voltage. Fourth, the electron density measured by the Stark broadening of Ar spectral line 696.5 nm reaches as high as 3× 10 16 cm-3, which yields a conductivity of the microplasma column of around 48 S m-1. In addition, the propagation velocity of the microplasma plume, obtained from light signals at different axial positions, ranges from 1 × 10 5 m s-1 to 5× 10 5m s-1. A detailed analysis reveals that the surface charges deposited on the inner wall exert significant influence on the discharge behavior of the microplasma.