激光触发真空沿面闪络开关的初步实验研究

 介绍了沿面闪络开关的发展状况和基本原理，实验研究了真空条件下激光触发介质沿面闪络特性。实验采用固体Nd:YAG纳秒激光器作为触发源，对试样施加正直流高压，电压范围1～6 kV，试样绝缘子为直径50 mm的尼龙6。通过研究不同激光能量、波长和聚焦形状对介质闪络的影响，总结出适用于沿面闪络开关的激光触发形式。实验表明：在一定电场和真空度下闪络的时延和抖动将随着输入激光能量的提高而减小，而激光可触发的电压范围将提高；激光波长减小有助于提高触发的稳定性；激光焦斑的形状是沿面闪络触发的最大影响因素，采用具有一定能量密度、焦斑横跨两电极的带状激光来触发闪络是闪络开关的理想选择。

Experimental study on laser triggered surface flashover switch in vacuum

Surface flashover switch have been investigated as a low inductance,low pulsed rate and low jitter command triggered switch.The development and mechanism of surface flashover switch are introduced in this paper.Experiments was carried out to study optically induced surface flashover characteristics.The Nd:YAG laser(wavelengthes are 1 024,532,355 nm) was used to induce flashover in the experiment.The DC flashover phenomena induced by laser with different wavelength,energy and focus shape were described.Experimental results indicated that the delay time and jitter was decreased at constant surface electric field strength with laser energy increase,and the range of triggering voltage was extended at the meantime.The jitter was decreasing with the decreasing laser wavelength.The focus spot shape was an important factor for insulation flashover in vacuum.The laser with a focus spot shape of a thick strip spanning the electrode gap is a good choice for closure switches.