螺旋脉冲形成线实验研究

Experimental study on helical Blumlein line

设计了一种用于长脉冲功率源研究的Blumlein型螺旋脉冲形成线。该形成线主要是将铜带绕在绝缘衬筒上形成螺旋形结构,以蓖麻油为介质,匝数为3.5匝每m,充电时间为1μs,负载为电子束二极管。给出了形成线参数的理论计算公式以及实验研究结果。在300 kV脉冲功率源上得到的脉冲延迟为200 ns,特征阻抗约100Ω,形成的脉冲半高宽为180 ns,前沿15 ns,平顶宽度150 ns。实验证明该螺旋脉冲形成线结构能够有效地延长形成脉冲的宽度。最后分析了开关电感、充电时间以及螺旋形结构对形成线输出脉冲前沿及平顶畸变的影响。结果表明:较小的主开关电感是形成较陡的脉冲前沿的关键,获得好的脉冲波形应选择适当的充电周期,螺旋形结构容易导致色散产生,需要选取适当的螺旋角。

This paper presents a kind of helical pulse forming line which is designed for a long pulse accelerator. The calculating formulae and the experimental result are both presented. The forming line is charged by a pulse source with a maximum output voltage of 300 kV. The length of helical line is 2.7 m,immersed in the castor oil. The pulse width about 200 ns is obtained. And the characteristic resistance is about 100 ohm. The effects of the switch inductance, charge time and spirality structure on the forming line output pulse are analysed that the helical structure can extend the pulse width efficaciously is proved by experiment.