Electron density fluctuations accelerate the branching of positive streamer discharges in air.
Electron density fluctuations accelerate the branching of positive streamer discharges in air.
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DOI：
10.1103/physreve.84.046411
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发表时间：
2011-02
期刊：
影响因子：
--
通讯作者：
A. Luque;U. Ebert
中科院分区：
文献类型：
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作者：
A. Luque;U. Ebert
分支是流注放电动力学的基本要素。我们回顾了目前的理论认识和回顾，分支需要一个有限的扰动。我们认为，在目前的实验室实验中，在环境或人工空气中，这些扰动只能从初始状态继承，或者它们可以是由于电子的离散性的内在电子密度波动。我们将这些电子密度的波动到一个积极的流光在空气中在标准温度和压力的完全三维模拟。我们推导出一个定量估计的分支长度流光直径的比率，同意在一个因子2与实验测量。由于没有这种噪声的分支将发生相当晚，如果在所有，我们得出结论，内在的随机粒子噪声触发分支的正流光在大气压力下的空气中。
Branching is an essential element of streamer discharge dynamics. We review the current state of theoretical understanding and recall that branching requires a finite perturbation. We argue that, in current laboratory experiments in ambient or artificial air, these perturbations can only be inherited from the initial state, or they can be due to intrinsic electron-density fluctuations owing to the discreteness of electrons. We incorporate these electron-density fluctuations into fully three-dimensional simulations of a positive streamer in air at standard temperature and pressure. We derive a quantitative estimate for the ratio of branching length to streamer diameter that agrees within a factor of 2 with experimental measurements. As branching without this noise would occur considerably later, if at all, we conclude that the intrinsic stochastic particle noise triggers branching of positive streamers in air at atmospheric pressure.