The flashover in vacuum is a rapid interfacial discharge across the insulator surface when subjected to high applied voltage. Here a theoretical model covering above-surface processes is introduced. The model calculates the flashover threshold in vacuum, with revised secondary electron emission avalanche theory and improved desorbed neutral transport model. The model serves as the first part of an integrated flashover model, aiming for consistent treatment of both above-surface and subsurface processes during the entire flashover development. The flashover threshold is obtained by combining the desorbed neutral pressure at given applied voltage and the gas breakdown criterion dictated by the Paschen's law. An analytical formula for threshold estimation containing physical parameters, and a simplified formula consisting of empirical coefficients are introduced, catering for both conceptual understanding and practical application. The derived formulae are validated by experimental data for a variety of insulator materials. The theory generalisation for non-uniform electric field distribution is further discussed.

中文翻译：

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真空闪络发展的集成建模：表面以上过程和击穿阈值分析

真空中的闪络是在施加高电压时穿过绝缘体表面的快速界面放电。这里介绍了一个涵盖地表以上过程的理论模型。该模型采用修正的二次电子发射雪崩理论和改进的解吸中性输运模型计算真空中的闪络阈值。该模型作为集成闪络模型的第一部分，旨在在整个闪络发展过程中对地上和地下过程进行一致的处理。闪络阈值是通过将给定施加电压下的解吸中性压力与帕邢定律规定的气体击穿标准相结合而获得的。引入了包含物理参数的阈值估计解析公式和由经验系数组成的简化公式，兼顾概念理解和实际应用。推导的公式通过各种绝缘体材料的实验数据得到验证。进一步讨论了非均匀电场分布的理论推广。