2008年4月24日行星际激波事件相关联的超热电子90&#176;掷角的增强

孔凡婧; 秦刚

doi:10.11728/cjss2019.02.143

2008年4月24日行星际激波事件相关联的超热电子90°掷角的增强

doi: 10.11728/cjss2019.02.143

孔凡婧^1,2,
秦刚³

1. 中国科学院国家空间科学中心空间天气学国家重点实验室北京 100190;
2. 中国科学院大学地球科学学院北京 100049;
3. 哈尔滨工业大学理学院深圳 518055

基金项目:

国家自然科学基金项目资助（NNSFC 41574172）

详细信息

作者简介:
孔凡婧,E-mail:fjkong@spaceweather.ac.cn

中图分类号: P353
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- 被引次数: 0
出版历程
- 收稿日期: 2018-04-20
- 修回日期: 2018-06-27
- 刊出日期: 2019-03-15

90°Pitch Angle Enhancements of Suprathermal Electrons Associated with the Interplanetary Shock on 24 April 2008

KONG Fanjing^1,2,
QIN Gang³

1. State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190;
2. College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049;
3. School of Science, Harbin Institute of Technology, Shenzhen 518055

摘要

摘要: 利用测试粒子数值模拟的方法研究了与STEREO-A卫星观测到的2008年4月24日行星际激波事件相关联的超热电子90°投掷角的增强.根据激波到达前给定时刻超热电子的观测分布，拟合得到不同投掷角的初始分布函数；在给定的激波参数下，采用时间向后的方法计算特定能道上激波下游超热电子的投掷角分布.由于超热电子具有较高的共振频率，模拟采用的磁场湍流谱包含了低能电子发生共振的耗散区.对以215.76，151.67，106.63，eV为中心的三个能道进行了模拟.结果表明，不同能道上超热电子在激波下游的投掷角分布均在90°投掷角附近出现峰值，呈现出明显的90°投掷角增强，这与观测结果符合得很好.可以认为在激波对电子的加速过程中，电子与湍流耗散区的共振对90°投掷角的增强具有重要作用.
- 超热电子 /
- 90°投掷角增强 /
- 粒子加速
Abstract: Using test particle simulations, the 90° pitch angle enhancements of suprathermal electrons associated with the interplanetary shock on 24 April 2008 observed by STEREO-A spacecraft have been studied. Firstly, the initial distribution function for each pitch angle channel is obtained by fitting the observed distribution at a given time before the shock arrival, and then the time-backward method is used to calculate the pitch angle distributions of suprathermal electrons downstream of the shock for a given energy channel. Due to the higher resonance frequency of suprathermal electrons, the turbulence spectrum includes the dissipation range in which low-energy electrons resonate. Three energy channels with central energies of 215.76 eV, 151.67 eV, and 106.63 eV are simulated. The results show that a peak of the pitch angle distributions downstream of the shock obtained for these energy channels appears near the 90° pitch angle. The enhancement at the 90° pitch angle is in good agreement with the observations. The resonance between suprathermal electrons and the turbulence dissipation range in the process of shock acceleration is suggested to play a crucial role in this phenomenon. A thorough study of the electric and magnetic field fluctuations at interplanetary shocks can provide a better understanding of the nature of 90° pitch angle enhancements of suprathemal electrons.
- Suprathermal electrons /
- 90° pitch angle enhancements /
- Acceleration of particles

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参考文献(25)

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