大气压氩气射流等离子体放电发展速度研究

利用交流空心针-板放电装置，在大气压环境中产生了两种不同极性的氩射流等离子体，利用放电产生的等离子体发光信号，研究了两种等离子的形貌和放电的发展速度。利用高速相机拍摄了两次放电的形貌，发现正半周放电长度约为0.8 cm，负半周放电长度约为1.6 cm。然后利用两个光电倍增管配合，分别测量了正负半周放电的发展速度，正半周放电发展速度为（3.1±0.2）×10⁶ cm/s，负半周放电发展速度为（2.2±0.1）×10⁷ cm/s，而且两次放电的发展方向相同。通过对电子激发温度空间分布的分析，发现电场是影响等离子发展速度的重要因素。

Propagation Velocity in Hollow Needle to Plate Discharge

Two kinds of atmospheric argon plasma jet were generated by hollow needle to plate discharge. The velocity of discharge propagation was measured by two photomultipliers (PMT) and the length of the discharge was recorded by an ICCD camera. It was found that the velocity and the length were different during different voltage phase. In the positive discharge, the length and the velocity were 0.8 cm and (3.1±0.2)×10⁶ cm/s, respectively. While in the negative discharge, they were 1.6 cm and (2.2±0.1)×10⁷ cm/s, respectively. However, the two discharges propagated along the same direction. Moreover, the distribution of excitation temperature was obtained. The results show that the electric field plays an important role in propagating of plasma jet.