Control of atmospheric glow discharge using liquid electrode and its application for plasma reactor

利用液态(电解液：氯化钠溶液)电极和轴向微小氦流，在环境空气中稳定地产生了大气层直流辉光放电。在液体阴极放电的情况下，当放电电流进一步增大时，在负辉光区观察到由电解液表面蒸发的钠原子产生的黄光发射。为考察液体电极温度的影响，采用喷射式冷却器或加热器控制电解液阴极温度。冷藏电解液阴极的钠发射强度降低，而加热的电解液阴极的钠发射强度增大。当使用脉冲调制直流电压时，钠的发射从放电开始有一段延迟时间出现，而氮分子线的发射出现并立即达到峰值。液阴极温度是控制放电过程中等离子体-液体相互作用的重要因素，也是解决电解液阴极放电详细机理的重要因素。当使用电解液作为阳极时，当产生带有氦流的大气压直流辉光放电时，在液体或金属表面观察到自组织阳极图案。图案的形成取决于电流、间隙长度和氦气流量。

An atmospheric DC glow discharge using liquid (electrolyte : NaCl solution) electrodes and axial miniature helium flow was generated stably in ambient air. In the case of liquid cathode discharge, when the discharge current was increased further, yellow light emission which was originated from sodium atoms vaporized from the electrolyte surface was observed in the negative glow region. To examine the effect of temperature of liquid electrode, we controlled the electrolyte cathode temperature using injection type cooler or heater. The intensity of the sodium emission decreased with the refrigerated electrolyte cathode, while it increased with the heated electrolyte cathode. When we use pulse modulated DC voltage, the sodium emission appeared with a delay time from the start of the discharge, while the emission of nitrogen molecular lines appeared and reached their peaks immediately. The temperature of liquid cathode is important factor to control the plasma-liquid interaction from the discharges and to resolve the detailed mechanism of the electrolyte cathode discharges. When we use electrolyte as anode, self-organized anode patterns were observed on the liquid or metal surface when atmospheric dc glow discharge with helium flow is generated. The pattern formation depends on the current, gap length and helium flow rate.