Precursor Wave Emission Enhanced by Weibel Instability in Relativistic Shocks
Precursor Wave Emission Enhanced by Weibel Instability in Relativistic Shocks
复制标题
相对论激波中韦贝尔不稳定性增强了前驱波发射
DOI：
10.3847/1538-4357/aaba7a
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Y. Matsumoto
中科院分区：
文献类型：
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作者：
M. Iwamoto;T. Amano;M. Hoshino;Y. Matsumoto
我们研究了双等离子体中磁化的纯垂直相对论激波的前驱波发射效率。我们将先前的研究扩展到包括上游磁场取向的依赖关系。我们进行了二维粒子单元模拟，重点研究了两种磁场取向：模拟平面内的磁场(即面内构型)和垂直于模拟平面的磁场(即面外构型)。我们在面内位形下的模拟表明，不仅激发了异常模波，而且激发了普通模波。我们量子化了发射效率作为磁化参数σe的函数，发现在很宽的σe范围内都有大幅度的前驱波发射，特别是在低σe时，由魏贝尔不稳定性产生的磁场放大了普通模波功率。振幅大到足以扰乱上游等离子体，并且产生了横向密度细丝，就像先前研究的平面外构型的情况一样。我们证实了我们之前的结论是成立的，而不考虑相对于二维模拟平面的上游磁场方向。在此基础上，讨论了相对论激波的三维前驱波发射和尾波场加速的可行性。
We investigated the precursor wave emission efficiency in magnetized purely perpendicular relativistic shocks in pair plasmas. We extended our previous study to include the dependence of upstream magnetic field orientations. We performed two-dimensional particle-in-cell simulations and focused on two magnetic field orientations: the magnetic field in the simulation plane (i.e., in-plane configuration) and that perpendicular to the simulation plane (i.e., out-of-plane configuration). Our simulations in the in-plane configuration demonstrated that not only extraordinary but also ordinary mode waves are excited. We quantified the emission efficiency as a function of the magnetization parameter σe and found that the large-amplitude precursor waves are emitted for a wide range of σe. We found that especially at low σe, the magnetic field generated by Weibel instability amplifies the ordinary mode wave power. The amplitude is large enough to perturb the upstream plasma, and transverse density filaments are generated as in the case of the out-of-plane configuration investigated in the previous study. We confirmed that our previous conclusion holds regardless of upstream magnetic field orientations with respect to the two-dimensional simulation plane. We discuss the precursor wave emission in three dimensions and the feasibility of wakefield acceleration in relativistic shocks based on our results.
DOI：
10.1088/0004-637x/715/1/429
发表时间：
2010-01
期刊：
The Astrophysical Journal
影响因子：
--
作者：
A. Abdo;A. Abdo;M. Ackermann;M. Ajello;A. Allafort;E. Antolini;E. Antolini;W. Atwood;M. Axelss
通讯作者：
A. Abdo;A. Abdo;M. Ackermann;M. Ajello;A. Allafort;E. Antolini;E. Antolini;W. Atwood;M. Axelss