Characteristics of the plasma sheath in helium discharge within dielectric tubes  

作　　者：吴淑群 郭玥 欧阳帆 周保伟 胡彪 程鹤 Shuqun WU;Yue GUO;Fan OUYANG;Baowei ZHOU;Biao HU;He CHENG(College of Automation Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,People's Republic of China;School of Chemistry and Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,People's Republic of China)

机构地区：[1]College of Automation Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,People's Republic of China [2]School of Chemistry and Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,People's Republic of China

出　　处：《Plasma Science and Technology》2023年第4期79-92,共14页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(No.51977110)。

摘　　要：To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath thickness in the plasma head is almost equal to the tube radius.It decreases rapidly to several micrometers at an axial distance of 0.05 mm behind the plasma head,and then slightly increases and saturates at the axial position far behind the plasma head.A plasma-gas sheath surrounding the central plasma column is observed for a tube diameter equal to or greater than 0.8 mm.It is replaced by a plasma-wall sheath for smaller tubes.With the decrease in the tube diameter,the sheath thickness far behind the plasma head decreases while the ion flux increases significantly.However,when O_(2)gas with a proportion of 2%is added,both the sheath thickness and ion flux decrease.

关 键 词：plasma sheath plasma modification helium discharge ion flux plasma jet 

分 类 号：O461[理学—电子物理学] O53[理学—物理]