Abstract

The dynamics of an electron avalanche starting from the flat cathode surface and from the tops of microtips of different heights on the cathode surface is compared. The dynamics of avalanches was simulated in a changing electric field of the forming cathode sheath of a self-sustained high-pressure volume discharge with preliminary ionization of the gaseous medium. The aim of this work was to study the possibility of the development of instability during the formation of the cathode sheath. It is shown that the start from the top of the microtip gives the avalanche an advantage both in the increase in the number of electrons and in the distance traveled in comparison with the avalanche that started from a flat surface. This advantage is due to the region of enhancement of the electric field produced by the microtip and increases with the height of the tip. Areas of increased plasma density formed by avalanches that start from microtips can create an initial inhomogeneity necessary for the development of instability during the formation of the cathode sheath. The possible mechanisms of the development of instability in the cathode sheath are analyzed.

中文翻译：

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自持体积放电形成阴极护套中电子雪崩动力学的数值研究

摘要

比较了从平坦的阴极表面和阴极表面不同高度的微尖端顶部开始的电子雪崩的动力学。雪崩的动力学是在气体介质初步电离的自持高压体积放电的形成阴极鞘的变化电场中模拟的。这项工作的目的是研究阴极护套形成过程中不稳定发展的可能性。结果表明，与从平坦表面开始的雪崩相比，从微尖端的顶部开始使雪崩在电子数量和行进距离的增加方面具有优势。这种优势是由于微尖端产生的电场增强区域，并随着尖端的高度而增加。由从微尖端开始的雪崩形成的等离子体密度增加的区域会产生初始不均匀性，这对于阴极鞘形成过程中不稳定的发展是必要的。分析了阴极鞘不稳定发展的可能机制.