Nanosecond-Resolved Discharge Processes Revealing Detailed Mechanisms of Nonequilibrium Atmospheric-Pressure Plasma Jet of Helium
Nanosecond-Resolved Discharge Processes Revealing Detailed Mechanisms of Nonequilibrium Atmospheric-Pressure Plasma Jet of Helium
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DOI：
10.1109/tps.2015.2419639
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发表时间：
2015-06
影响因子：
1.5
通讯作者：
N. Jiang;X. Shao;Guanjun Zhang;Z. Cao
中科院分区：
文献类型：
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作者：
N. Jiang;X. Shao;Guanjun Zhang;Z. Cao
在实验装置的不同部分和放电的不同发展阶段获得了用传统介质阻挡放电装置产生的非平衡大气压氦等离子体射流的纳秒分辨照片，表明各种不同的机制是同时运行的。来自位于下游侧的活性电极的外边缘的流光在空气中形成射流，只有当接近气体导管的孔口时才变成中空的。来自内边缘的流光暂时滞后，并沿着螺旋路径传播，并在到达接地电极时引发辉光放电。活性电极下方的电子沉积物从两侧向内扩展，表现出类似孤子的行为；而接地电极下方的非常致密的离子沉积物（典型的离子流光）从电极的内边缘向外延伸。空气中的射流和电极之间的流光的速度比装置其他部分的速度大得多。这些特定工艺和特征的解决可以改善这种有价值的冷等离子体源的实施。
Nanosecond-resolved photographs of the nonequilibrium atmospheric-pressure plasma jet of helium, generated with the conventional dielectric barrier discharge device, were obtained at different sections of the experimental setup and at different development stages of the discharges, showing that various distinct mechanisms are simultaneous in operation. The streamer from the outer edge of active electrode sitting at downstream side forms a jet in air, which only turns out to be hollow when approaching the orifice of the gas conduct. The streamer from the inner edge temporally lags behind, and it propagates along a helical path and initiates the glow discharge when arriving at the ground electrode. The electron deposit beneath the active electrode expands inward from both sides, displaying a soliton-like behavior; while the very compact ion deposit beneath the ground electrode, a typical ionic streamer, extends outward from the inner edge of the electrode. The velocities of the jet in air and of the streamer between electrodes are much larger than those at other parts of the device. The resolution of these particular processes and features can improve the implementation of this valuable cold plasma source.