Air Effects on the External SGEMP Response of a Cylinder

Observation of Pressure-Dependence in RF-Modulated Electron Beam Interactions With a Resonant Cylindrical Cavity

“…The results of the analysis and experiments in this work, wherein we consider a microwave-modulated electron LINAC beam, are broadly consistent with results from the literature, which explore single-pulse SGEMP interactions with cavities held at various pressures [1], [2], [3], [13], [14], [17], similarly demonstrating four regimes of pressure-dependence corresponding to no plasma, a field-driven plasma, collisionand field-driven plasma, and a collision-driven plasma. The experimental and analytic results from this work indicate that these regime boundaries will generally depend on beam parameters, as well as the cavity geometry.…”

“…SGEMP interactions with resonant structures have been explored elsewhere analytically [3], experimentally [13], and using both 2-D [2] and 3-D [1] electromagnetic particle-in-cell codes. Of considerable interest in these problems is the impact of initial gas density and ionization inside of the resonant structure [14] and variations in photon fluence, spectrum, and pulsewidth [17]. However, in all prior work, the X-ray and/or electron pulse is a single 1-10-ns burst [18], as opposed to a periodic sequence of micropulses (tens of picoseconds), which is the focus of this work.…”

Hybrid Modelling of Cavity SGEMP in Low Pressure Air

“…为了降低实验复杂性与成本， SGEMP 的实验研究往往通过直接注入高能电 子束来模拟光电子， 避免使用大型射线源， 即便如此， 相关实验的难度依然很高， 公开的实验数据也非常稀缺 [4]- [6] .因此，数值模拟已经成为研究 SGEMP 的重要手 段， 代表性成果是美国 Woods 等人 [7] 编制的二维模拟程序 ABORC.以往的研究中， 真空环境下的 SGEMP 一直是关注的重点 [8] .近五年左右，西北核技术研究所的 Wang 等人基于自研程序 UNIPIC-3D [9] [10] 对 SGEMP 进行模拟，该程序支持辛算 法以及共形网格 [11] ，可以有效处理系统电磁脉冲中的电子发射边界问题 [12] .国内 研究人员对其中存在的空间电荷限制效应 [13] [14] 、 壁面二次电子发射 [15] 等问题也进 行了广泛的研究 [16] . 然而，实际系统往往工作在气体环境或含有充气元器件，光电子与中性气 体间会通过碰撞电离产生大量的次级电子、离子对，次级电子又会从电磁场中获 得能量，继续与中性气体发生电离、激发等一系列反应，从而形成等离子体.实验 结果表明 [17] ，等离子体与电磁场的相互作用会使 SGEMP 的特性会发生显著变 化.Woods 等人 [18] 最早通过数值模拟研究了高空稀薄空气和预电离空气对 SGEMP 的影响， 结果表明， 随着气压升高， 空间电荷层被破坏， 系统表面电流增加 [19] .Chan 等人 [20] 与 Strasburg 等人 [21] 使用电导率模型描述稀薄空气等离子体.Pusateri 等人 [22] 基于 swarm 模型对高空核爆电磁脉冲中的二次电子进行建模.Angus 等人 [23] 建立 了零维反应动力学模型，研究电子束诱导稀薄空气等离子体中的主要反应.…”

Contribution of Electromagnetic Perturbation to the Transient Response of an Electronic Circuit Exposed to a High Multi-MeV X-Ray Flux

“…TREE effects have been widely reported in the literature, for various IC technologies and various dose and dose rate conditions. SGEMP effects have been studied in the past, mostly through EM fields generation in vacuum [9] and in air [10], as well as x-ray generated EM fields coupling on cables [11], [12].…”