Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock
Abstract Electron beams are considered to be important free energy sources for the excitation of various plasma waves at quasi‐perpendicular shocks. In this article, we perform a two‐dimensional particle‐in‐cell simulation of a low‐plasma‐β quasi‐perpendicular shock. The magnetic field at the shock...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2025-03-01
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| Series: | Geophysical Research Letters |
| Online Access: | https://doi.org/10.1029/2024GL114425 |
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| _version_ | 1849313606245548032 |
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| author | Ao Guo Quanming Lu San Lu Xinliang Gao Zhongwei Yang |
| author_facet | Ao Guo Quanming Lu San Lu Xinliang Gao Zhongwei Yang |
| author_sort | Ao Guo |
| collection | DOAJ |
| description | Abstract Electron beams are considered to be important free energy sources for the excitation of various plasma waves at quasi‐perpendicular shocks. In this article, we perform a two‐dimensional particle‐in‐cell simulation of a low‐plasma‐β quasi‐perpendicular shock. The magnetic field at the shock ramp has a large gradient, where upstream electrons and ions are separated due to their different gyro‐radius. This charge separation induces a sub‐ion scale electric field at the shock ramp. The electric drift of electrons in this field can induce an electron shear flow, resulting in the excitation of Kelvin‐Helmholtz instability and the generation of electron vortices. These vortices further cause charge separation at their centers, resulting in a large electrostatic field. The electrons trapped in these vortices can gain energy from the parallel component of the electric field, which eventually leads to field‐aligned electron beams. Our results provide a novel process for generating electron beams at low‐plasma‐β quasi‐perpendicular shocks. |
| format | Article |
| id | doaj-art-e33e0588cce845b3a19f65e6d22683e5 |
| institution | Kabale University |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-e33e0588cce845b3a19f65e6d22683e52025-08-20T03:52:42ZengWileyGeophysical Research Letters0094-82761944-80072025-03-01525n/an/a10.1029/2024GL114425Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular ShockAo Guo0Quanming Lu1San Lu2Xinliang Gao3Zhongwei Yang4CAS Key Lab of Geospace Environment School of Earth and Space Sciences University of Science and Technology of China Hefei ChinaCAS Key Lab of Geospace Environment School of Earth and Space Sciences University of Science and Technology of China Hefei ChinaCAS Key Lab of Geospace Environment School of Earth and Space Sciences University of Science and Technology of China Hefei ChinaCAS Key Lab of Geospace Environment School of Earth and Space Sciences University of Science and Technology of China Hefei ChinaState Key Laboratory of Solar Activity and Space Weather National Space Science Center Chinese Academy of Sciences Beijing ChinaAbstract Electron beams are considered to be important free energy sources for the excitation of various plasma waves at quasi‐perpendicular shocks. In this article, we perform a two‐dimensional particle‐in‐cell simulation of a low‐plasma‐β quasi‐perpendicular shock. The magnetic field at the shock ramp has a large gradient, where upstream electrons and ions are separated due to their different gyro‐radius. This charge separation induces a sub‐ion scale electric field at the shock ramp. The electric drift of electrons in this field can induce an electron shear flow, resulting in the excitation of Kelvin‐Helmholtz instability and the generation of electron vortices. These vortices further cause charge separation at their centers, resulting in a large electrostatic field. The electrons trapped in these vortices can gain energy from the parallel component of the electric field, which eventually leads to field‐aligned electron beams. Our results provide a novel process for generating electron beams at low‐plasma‐β quasi‐perpendicular shocks.https://doi.org/10.1029/2024GL114425 |
| spellingShingle | Ao Guo Quanming Lu San Lu Xinliang Gao Zhongwei Yang Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock Geophysical Research Letters |
| title | Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock |
| title_full | Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock |
| title_fullStr | Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock |
| title_full_unstemmed | Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock |
| title_short | Electron Beams Generated by the Electron Kelvin‐Helmholtz Instability at a Quasi‐Perpendicular Shock |
| title_sort | electron beams generated by the electron kelvin helmholtz instability at a quasi perpendicular shock |
| url | https://doi.org/10.1029/2024GL114425 |
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