对单针电极射流等离子体产生和发展过程中的光信号进行了研究。首先发现等离子体的长度并不是随外加电压升高而增加, 而是和驱动电源的能量在正半周放电脉冲之间的分配有关。通过研究等离子体通道内不同位置的发光信号, 发现正半周期第一次放电脉冲是在针尖电极处产生, 而第二个脉冲是在等离子体通道中部产生, 电子激发温度也是在等离子体中部达到最高。通过分析发现, 空间电荷产生的附加电场对于等离子体的产生和发展有着重大影响。

The light signal in the generation and propagation of plasma jet produced by the single needle electrode was studied. It is found that the length of plasma jet does not increase with the applied voltage, but relates to the distribution of energy between pulse discharges(PD) in the positive half-cycle. The first PD is produced at the needle electrode, the second PD is produced in the middle of plasma channel where the electron excitation temperature reaches its highest value. We conclude that the additional electric field generated by space charge has great influence on the generation and development of plasma jet.