The atmospheric pressure multi-plasma jet produces an array of individual plasma jets which originate from the branching of a single ionization wave (IW). The use of arrays of such plasma jets could enable treatment of larger surface areas than is possible with a single plasma jet. In this paper, we discuss results from a combined experimental and two-dimensional modeling investigation of the behavior of IWs in an atmospheric pressure plasma multi-jet device. In this multi-jet, a rare gas is flowed through a tube having a line of holes, producing gas jets into the ambient from each of the holes. A primary ionization wave (PIW) propagates through the tube which launches a series of secondary ionization waves (SIWs) propagating out each hole through the plumes of the individual gas jets. The propagation of the SIWs is more intense using a positive polarity voltage pulse due to the higher electric field at the ionization front. The diameter of the holes determines the delay of the SIW after passage of the PIW past the hole, with smaller holes resulting in larger delays. The larger delay results from a smaller view angle for photoionization outside the tube from photons originating in the PIW. Higher helium flow rates result in a greater tendency for SIW propagation because the air concentrations in the individual gas jets outside the tube are lower and so the electron temperature is higher. The interaction between SIWs is primarily electrostatic, and is a sensitive function of geometric parameters including proximity of ground planes and the spacing between the holes through which these SIWs emerge.

中文翻译：

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大气压等离子体多射流中的电离波传播

大气压多等离子体射流产生一系列单独的等离子体射流，这些射流源自单个电离波 (IW) 的分支。使用这种等离子射流阵列可以处理比单个等离子射流更大的表面积。在本文中，我们讨论了大气压等离子体多射流装置中 IW 行为的联合实验和二维建模研究的结果。在这种多射流中，稀有气体流过具有一排孔的管子，产生从每个孔进入环境的气体射流。初级电离波 (PIW) 通过管传播，该管发射一系列次级电离波 (SIW)，通过各个气体射流的羽流从每个孔中传播出去。由于电离前沿的电场较高，使用正极性电压脉冲使 SIW 的传播更加强烈。孔的直径决定了 PIW 通过孔后 SIW 的延迟，较小的孔会导致较大的延迟。较大的延迟是由于来自 PIW 的光子在管外进行光电离的较小视角造成的。较高的氦气流速导致 SIW 传播的趋势更大，因为管外单个气体射流中的空气浓度较低，因此电子温度较高。SIW 之间的相互作用主要是静电作用，并且是几何参数的敏感函数，包括接地平面的接近度以及这些 SIW 出现的孔之间的间距。