纳秒脉冲放电等离子体射流特性

采用单针式电极，使用单极性重复频率脉冲电源，在常压氦气、氩气、氮气和空气中得到等离子体射流，并改变电压、流量和气体种类，分别观察不同的实验条件对等离子体射流的影响。实验结果表明:射流长度随施加电压的增加而增长；随着流量的连续变化，射流长度先逐渐变长，达到峰值后由于湍流影响，长度又逐渐缩短，达到一定流量后趋于饱和。此外，不同工作气体中的等离子体射流呈现截然不同的外观，氦气和氩气中射流呈针状模式，长度可达7 cm以上；而在氮气和空气中，射流呈现为长度不超过2 cm的刷状模式。

Characteristics of nanosecond-pulse atmospheric pressure plasma jet

In the experiments, with the use of a single needle electrode, atmospheric pressure plasma jets are excited by a repetitive unipolar nanosecond-pulse generator, with working gases such as helium, argon, nitrogen and air. The results show that the jet length increases with the rise of applied voltage; as the flow rate of working gas increases, the length of jet becomes gradually longer and then reduces gradually to saturation after a certain flow rate due to turbulence. In addition, the plasma jets of different working gases have very different appearances. Helium and argon gas jets are needle-like, and the longest jet length is over 7 cm; whereas in nitrogen and in air, the jet is no more than 2 cm long, of brush-like mode.