Abstract

Localized plasma formations called space leaders are observed in streamer coronas of negative leaders of long laboratory sparks. The main leader completes a step when the space leader comes into contact with the head of the main leader. In the present work, we discuss the creation mechanism of local plasma formations (henceforth, generally, referred to as the hot spots) that are able to initiate a space leader. It is assumed that spontaneous increase in the conductivity in a local region of one of the streamers of the main leader corona initiates two secondary coronas from the ends of this region. The corona current warms up the region, leading to formation of the hot spot, provided that the magnitude of the field in the heated region is sufficiently high. Finally, hot spots grow into the space leader with further increase in the temperature and conductivity. The necessary condition for achieving the temperature of ≈2000 K in the hot spot within the observation time of t_obs ≤ 1 µs is the magnitude of the ambient electric field strength E₀ = 20 kV cm^–1 that is almost twice higher than the average magnitude of the electric field strength of ≈11 kV cm^–1 in a negative corona.

中文翻译：

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加热支流拖缆的局部区域，以此作为空间领导者和负领导者的出发点

摘要

在长实验室火花的负先导的流光晕中观察到称为空间先导的局部等离子体形成。当空间负责人与主要负责人的头部接触时，主要负责人完成了一个步骤。在当前的工作中，我们将讨论能够引发太空领导者的局部等离子体形成的机制（此后通常称为热点）。假定在主引导电晕之一的拖缆的局部区域中电导率的自发增加从该区域的端部引发两个次级电晕。只要加热区域中的电场强度足够高，电晕电流就会加热该区域，导致形成热点。最后，随着温度和电导率的进一步提高，热点逐渐成为空间领导者。在观测时间内在热点达到≈2000 K温度的必要条件t _obs≤1 µs是环境电场强度E ₀ = 20 kV cm ^–1的强度，几乎是负电晕中≈11kV cm ^–1的电场强度的平均强度的两倍。