中文摘要：

短间隙流注放电通道在发展过程中产生的流注分叉现象能使放电所输出的能量和产生的活性物质分布更加均匀。为此，研究了短空气放电间隙长度和电极形状对流注分叉的影响。使用输出电压峰值为52kV，电压上升时间约35ns的脉冲电源分别对间隙长度≤5cm的针-板、针-棒间隙进行放电，实验测试了不同间隙长度下流注的分叉特性。实验结果表明：间隙长度大于某一值（针-板间隙为3．5cm，针一棒间隙为3cm）时，观察到的流注分又数目和分又的发光强度随着间隙长度的增大而减少；而当间隙长度小于该值时，所拍摄的放电照片中流注通道很宽而且明亮，且很少有分叉。另外，相对于针-板间隙而言，在针-棒间隙中分叉的流注更容易向棒电极两端运动，产生重连接现象的概率更高。

英文摘要：

In short air gaps, streamer discharge channels usually split into several branches, which is called streamer branching. Streamer branching can make the distribution of discharge energy and active species more even. Thus, we studied the effects of gap length and electrode shape on streamer branching. Using a pulsed power supply with 52 kV output and rising time of 35 ns, we performed discharge experiments with a needle-plate gap and a needle-rod gap, and observed the streamer branching in two gaps with various lengths within 5 cm. The results show that there is a certain length, namely 3.5 cm for the needle-plate gap and 3 cm for the needle-rod gap, above which the number and luminous intensity of streamer branches decreases with the increase of gap length. While, for gaps with lengths below this value, there are wide and bright streamer channels but few branches. Moreover, compared with the needle-plate gap, in the needle-rod gap, branching streamers move towards both ends of the rod electrode more frequently and hence reconnections are easier to happen.