He二维射流阵列放电模式转换条件实验

为获得高强度和大面积大气压下等离子体射流,利用类蜂巢状电极结构,在大气压He中获得了两种不同模式的二维射流阵列放电,比较了它们的放电特性,并研究了气流速度、射流单元之间距离和外加电压幅值等参数对射流阵列模式转换的影响。结果表明,He中射流阵列在一定条件下会出现具有较高放电强度的强耦合模式和具有较大放电面积的均匀模式两种放电模式,相同的外加电压幅值下,强耦合模式阵列的放电功率、传输电荷和主要粒子谱线强度均高于均匀模式。射流单元之间距离和气体流速是影响射流阵列模式转换的主要决定因素,外加电压的变化只会影响到放电强度而不会影响到射流阵列的放电模式。射流单元之间距离为0.2mm,流速小于5L/min时,放电模式为强耦合模式;流速大于5L/min放电转换到均匀模式;当射流单元之间的距离超过0.4mm时,放电只出现均匀模式。

Experimental Investigation on Transition Conditions of Discharge Modes in Atmospheric Pressure Two-Dimensional Jet Array in He

For obtaining jet plasma with high strength and large area, two distinct modes of two-dimensional plasma jet array discharge at atmospheric pressure in He are generated with honeycomb like electrode arrangements. The discharge characteristics of the two modes array are studied and compared. The influence of the parameters such as the gas flow rate, distance between the jet units and voltage amplitude on mode transition of the jet array is studied. Results show that the jet arrays in He appear two modes, one is intense-coupling mode with high discharge strength and the other is even mode with relative large discharge area. At the same applied voltage amplitude, the discharge power, transmission charge and intensity of the main particle lines in the former mode are higher than those in the latter mode. The distance among the jet units and the gas flow rate are the main factors affecting mode transition of the jet array, while the change in voltage amplitude only affect discharge strength of the jet arrays without affecting mode transition. The discharge is in intense-coupling mode when the distance among the jet units is 0.2mm and the gas flow rate is less than 5L/min, and it will transit to even mode when the gas flow rate is larger than 5L/min. When the distance among the jet units is greater than 0.4mm, the discharge is only in even mode no matter what changes of the applied voltage or gas flow rate.