摘要
针对巴申曲线在低真空范围击穿特性尚无详细研究,且只适用于均匀电场的情况,本文研究了10-3~10 Pa低真空范围微秒脉冲下两电极开关击穿特性,在真空击穿试件内进行不同球电极间隙距离的真空击穿实验,探索并总结了其击穿规律。首先,对不同电极间距下放电腔场强分布进行了仿真,结果显示场分布为稍不均匀场,场强最大值集中在电极球面顶点之间。然后采用光学显微镜观察实验后电极表面状态,分析了击穿场强以及离散度随真空度和电极间隙的变化规律。结果表明:阴极烧蚀比阳极更为明显,小间隙下真空击穿主要为阴极引发;击穿场强随气压不断降低而迅速增大,上升斜率先增后减,击穿场强趋于稳定,该现象与真空击穿规律相符合;真空击穿场强离散度也随真空度变大,证明真空击穿的随机性和分散性较大。
The breakdown characteristics of the Paschen curve in the low vacuum range are not revealed in detail, and it is only applicable to the case of uniform electric field. This paper explores the breakdown characteristics of 10-3-10 Pa in microsecond pulse of two-electrode switch. The vacuum breakdown test was carried out with spherical electrode at different electrode spacing to explore and summarize its breakdown rules. Firstly, the field intensity distribution of the discharge cavity with different electrode spacing is simulated. The simulation results show that the field distribution is slightly uneven, and the maximum field intensity is concentrated between the spherical vertices of the electrodes. Then, the state of the electrode surface after the experiment is observed by optical microscope, and the variation of the breakdown field strength and dispersion with the vacuum degree and electrode gap is analyzed. The results show that the ablation of cathode is more obvious than that of anode,and the vacuum breakdown is mainly caused by cathode in small gap. The breakdown field strength increases rapidly with the decrease of pressure, the rising slope increases first and then decreases, and the breakdown field strength tends to be stable,which accords with the rule of vacuum breakdown. The dispersion of vacuum breakdown also increases with vacuum degree,which verifies the randomness and dispersion of vacuum breakdown.
作者
夏际炉
张自成
刘世飞
李典耕
XIA Ji-lu;ZHANG Zi-cheng;LIU Shi-fei;LI Dian-geng(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;State Key Laboratory of Pulsed Power Laser Technology,Changsha 410073,China)
出处
《真空》
CAS
2023年第2期63-67,共5页
Vacuum
基金
湖南省自然科学基金项目(2017JJ1005)。
关键词
微秒脉冲
真空击穿
低真空
microsecond pulse
vacuum breakdown
low vacuum
