...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Geophysical Research. Biogeosciences >Particle acceleration and coronal mass ejection driven shocks: A theoretical model
【24h】

Particle acceleration and coronal mass ejection driven shocks: A theoretical model

机译：粒子加速和日冕物质抛射驱动的冲击：理论模型

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

There is increasing evidence to suggest that energetic particles observed in "gradual" solar energetic particle (SEP) events are accelerated at shock waves driven out of the corona by coronal mass ejections. Energetic particle abundances suggest too that SEPs are accelerated from in situ solar wind or coronal plasma rather than from high-temperature flare material. A dynamical time-dependent model of particle acceleration at a propagating, evolving interplanetary shock is presented here. The theoretical model includes the determination of the particle injection energy (injection here refers to the injection of particles into the diffusive shock acceleration mechanism), the maximum energy of particles accelerated at the shock, energetic particle spectra at all spatial and temporal locations, and the dynamical distribution of particles that escape upstream and downstream from the evolving shock complex. As the shock evolves, energetic particles are trapped downstream of the shock and diffuse slowly away. In the immediate vicinity of the shock, broken power law spectra are predicted for the energetic particle distribution function. The escaping distribution consists primarily of very energetic particles initially with a very hard power law spectrum (harder than that at the shock itself) with a rollover at lower energies. As the shock propagates further into the solar wind, the escaping ion distribution fills in at lower energies, and the overall spectrum remains hard. Downstream of the shock, the shape of the accelerated particle spectrum evolves from a convex, broken power law shape near the shock to a concave spectrum far downstream of the shock. Intensity profiles for particles of different energies are computed, and the relation between arrival times, maximum predicted energies, and shock propagation characteristics are described. These results are of particular importance in the context of predictive space weather studies. [References: 57]
机译：越来越多的证据表明，在“渐进式”太阳高能粒子（SEP）事件中观察到的高能粒子在日冕物质抛射驱出日冕时会加速。高能粒子的丰度也表明，SEP是由原位太阳风或日冕等离子体加速而不是由高温火炬物质加速。在这里，提出了在传播的，不断发展的行星际激波下，粒子加速的动力学模型。理论模型包括确定粒子注入的能量（此处的注入是指将粒子注入到扩散的冲击加速机制中），在冲击中加速的最大粒子能量，在所有时空位置的高能粒子光谱以及从不断发展的激波复合体的上游和下游逸出的颗粒的动态分布。随着冲击的发展，高能粒子被困在冲击的下游并缓慢扩散开。在冲击的紧邻范围内，预测了高能粒子分布函数的破裂幂律谱。逃逸分布主要由高能粒子组成，这些粒子最初具有非常高的幂律谱（比电击本身更强），并且在较低能量下会发生翻转。随着冲击进一步传播到太阳风中，逃逸的离子分布以较低的能量填充，并且整个光谱仍然很硬。在冲击的下游，加速粒子光谱的形状从冲击附近的凸，折幂定律形状演变为冲击下游的凹光谱。计算了不同能量的粒子的强度分布，并描述了到达时间，最大预测能量和冲击传播特性之间的关系。这些结果在预测性空间天气研究的背景下特别重要。 [参考：57]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号