大气压空气纳秒脉冲板-板放电中逃逸电子产生机理  

Mechanism of runaway electron generation in nanosecond pulsed plate-plate discharge at atmospheric-pressure air

作　　者：肖江平 戴栋[1] Victor F.Tarasenko 邵涛[3] Xiao Jiang-Ping;Dai Dong;Victor FTarasenko;Shao Tao(School of Electric Power,South China University of Technology,Guangzhou 510641,China;Institute of High Current Electronics,Russian Academy of Sciences,Tomsk 634055,Russia;Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]华南理工大学电力学院,广州510641 [2]俄罗斯科学院大电流研究所,俄罗斯托木斯克634055 [3]中国科学院电工研究所,北京100190

出　　处：《物理学报》2023年第10期233-241,共9页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2021YFE0114700);国家自然科学基金(批准号:51877086)资助的课题。

摘　　要：经典放电理论(Townsend和流注理论)解释纳秒脉冲气体放电存在局限性,近年来基于高能电子逃逸的纳秒脉冲气体放电理论研究受到广泛关注.但是目前对大气压空气纳秒脉冲板-板放电中逃逸电子产生机理研究仍较少,严重阻碍了纳秒脉冲放电等离子体的应用发展.本文利用一维粒子模型,对幅值为20 kV的纳秒脉冲电压驱动下,间隙长为1 mm的板-板电极之间的大气压空气放电中逃逸电子的产生机理进行了数值模拟研究..结果表明,在空间电荷动力学行为的影响下,板-板电极之间出现了增强电场区域,使得电子可以满足电子逃逸判据而进入逃逸模式.此外,还观察到放电通道前逃逸电子的预电离效应导致了二次电子崩的产生,随着二次电子崩与放电通道不断汇聚,引导并加速了放电通道的发展,最终导致气隙击穿.本研究进一步揭示了纳秒脉冲板-板放电机理,拓展了纳秒脉冲气体放电基础理论,为纳秒脉冲放电等离子体的应用和发展开辟了新的机会.Classical discharge theory(Townsend theory and streamer theory)has limitations in explaining nanosecond pulsed gas discharge.In recent years,the research on nanosecond pulsed gas discharge theory based on the high-energy runaway electrons has attracted extensive attention.But so far,there have been few studies of the generation mechanism of runaway electrons in atmospheric-pressure-air nanosecond pulsed plate-to-plate discharge,which seriously hinders the application and development of nanosecond pulse discharge plasma.In this paper,a one-dimensional implicit particle-in-cell/Monte Carlo collision(PIC/MCC)model is developed to investigate the mechanism of runaway electron generation and breakdown in a 1 mm-long atmospheric-pressure-air gap between the plate electrode and plate electrode driven by a negative nanosecond pulse voltage with an amplitude of 20 kV.The results show that under the influence of space charge dynamic behavior,the electric field enhancement region appears between the plate electrode and plate electrode,so that electrons can satisfy the electron runaway criteria and behaves in the runaway mode.In addition,it is also observed that the pre-ionization effect of the runaway electrons in front of the discharge channel can cause the secondary electron avalanches.As the secondary electrons avalanche and the discharge channel continues to converge,the discharge is guided and accelerated,eventually leading to the breakdown of the air gap.This study further reveals the mechanism of nanosecond pulsed plate-plate discharge,expands the basic theory of nanosecond pulsed gas discharge,and opens up new opportunities for the application and development of nanosecond pulsed discharge plasma.

关 键 词：纳秒脉冲放电 逃逸电子 增强电场 预电离 

分 类 号：O461[理学—电子物理学]