Applied Physics Letters
Although the formation and propagation of plasma plume for atmospheric pressure plasmas have been intensively studied, how does the plasma plume terminate is still little known. In this letter, helium plasma plumes are generated in a long quartz tube by pulsed voltages and a constant gas flow. The voltages have a variable pulse width (PW) from 0.5 μs to 200 μs. It is found that the plasma plume terminates right after the falling edge of each voltage pulse when PW < 20 μs, whereas it terminates before the falling edge. When PW is larger than 30 μs, the duration of plasma plume starts to decrease, and the termination is found to occur at the current zero moment of the discharge current through the high-voltage electrode, which is much different from that through the ground electrode. This indicates that part of the discharge current is shunted by the plasma plume to its downstream gas region. An equivalent circuit model is developed, from which the surface charge deposited on the quartz tube is found crucial for accelerating the termination of a plasma plume when PW > 30 μs.
Original Publication Citation
Mingzhe, R., Wenjie, X., Xiaohua, W., Zhijie, L., Dingxin, L., Zhihu, L., . . . Kong, M. G. (2017). The mechanism of plasma plume termination for pulse-excited plasmas in a quartz tube. Applied Physics Letters, 111(7), 1-4. doi: 10.1063/1.4985332
Rong, Mingzhe; Xia, Wenjie; Wang, Xiaohua; Liu, Zhijie; Liu, Dingxin; Liang, Zhihu; Zhang, Xiaoning; and Kong, Michael G., "The Mechanism of Plasma Plume Termination for Pulse Excited Plasmas in a Quartz Tube" (2017). Bioelectrics Publications. 144.
0000-0003-3091-0032 (Wen Jie Xia), 0000-0002-6410-2319 (Xiaohua Wang), 0000-0003-0910-2903 (Dingxin Liu)