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Ion-focused propagation of a relativistic electron beam in the self-generated plasma in atmosphere 下载免费PDF全文
Jian-Hong Hao 《中国物理 B》2022,31(6):64101-064101
It is known that ion-focused regime (IFR) can effectively suppress expansion of a relativistic electron beam (REB). Using the particle-in-cell Monte Carlo collision (PIC-MCC) method, we numerically investigate the propagation of an REB in neutral gas. The results demonstrate that the beam body is charge neutralization and a stable IFR can be established. As a result, the beam transverse dimensions and longitudinal velocities keep close to the initial parameters. We also calculate the charge and current neutralization factors of the REB. Combined with envelope equations, we obtain the variations of beam envelopes, which agree well with the PIC simulations. However, both the energy loss and instabilities of the REB may lead to a low transport efficiency during long-range propagation. It is proved that decreasing the initial pulse length of the REB can avoid the influence of electron avalanche. Using parts of REB pulses to build a long-distance IFR in advance can improve the beam quality of subsequent pulses. Further, a long-distance IFR may contribute to the implementation of long-range propagation of the REB in space environment. 相似文献
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针对微波脉冲激励下复杂屏蔽腔体内部电路耦合电磁量计算的问题,建立了一个微波混沌腔体,通过测试获取了含内部电路的腔体辐射和辐射散射参数,利用随机耦合模型(RCM),对干扰脉冲能量进行了归一化处理,计算分析了微波脉冲宽度、脉冲间隔、脉冲数目以及腔体损耗因子对目标点感应电磁量统计分布的影响。计算结果表明:脉冲干扰下电路目标点耦合电磁量强于功率源激励;在脉冲能量一定的条件下,目标点耦合电磁量与微波脉冲的宽度、间隔和数目的变化均呈现一定的谐振特性,且单脉冲激励对电路的影响明显强于多脉冲。与此同时,实验还研究了电路易受电磁干扰的目标点的确定方法。 相似文献
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探地雷达对于电力接地网检测来说,是一种新型的检测方式,根据探地雷达在检测接地网过程中返回的图像提取目标信息实现对电力接地网的检测,对于检测地下导体的完整性方面有着较强的适用性和非凡意义。传统双曲线提取算法通常采用LOG算子完成边缘检测,借助雷达有效口径及扫描点间距完成对雷达双曲线顶点的寻找。在前人工作的基础上提出了采用Canny算子进行边缘检测,再进行双曲线提取的雷达直达波滤除以及目标识别算法,并与相关算法进行对比实验,得到比较完整的雷达目标反射图像,验证了算法的可行性。与传统雷达目标双曲线提取方式相比,该算法避免了雷达有效口径及扫描点间距的引入,提升了目标双曲线的完整性,精确性。 相似文献
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