【作者】 吕丹；

【导师】 汪洋；

【作者基本信息】 哈尔滨工业大学 ， 物理学， 2019， 硕士

【摘要】 太阳高能粒子(SEP)事件对人类的航天活动有极大的影响,对于太阳高能粒子事件的研究有助于理解太阳高能粒子在日球层中传播和加速过程的物理机制。利用多卫星联合观测经常能看到有趣的蓄水池现象:处在行星际不同经度,不同纬度,不同日心距离的观测者,看到在高能粒子上升相期间,粒子通量差别很大,但是到了事件下降期,这些卫星观测到的通量几乎接近一致的现象。本文将通过不同太阳活动周,将黄道面内不同经度以及不同径向距离的卫星进行太阳高能粒子事件质子蓄水池现象的联合观测。数据来自第21太阳活动周的卫星Helios 1&2与IMP-8,以及第23-24太阳活动周的卫星STEREO A&B与SOHO。我们从观测期的300多个太阳高能粒子事件中观测到了24个质子蓄水池事件,并进行了分类和分析。通过分析观测结果,我们发现:(1)高能粒子事件峰值越大,持续时间越长,越容易发生蓄水池现象。(2)粒子的能量越高,蓄水池现象更加容易出现。(3)在一个太阳高能质子事件中,如果Helios 1&2两颗卫星能够观测到蓄水池现象,基本上这个现象也会在IMP-8观测中出现;并且STEREO A&B与SOHO的联合观测结果也显示出这种内在联系。基于以上的观测结果,我们认为:(1)黄道面质子蓄水池的形成主要受激波主导,行星际的横向扩散和磁镜效应不起主导作用。(2)相对能量较低的粒子而言,高能粒子的注入过程主要发生在离太阳比较近的地方。在粒子注入过程中,高能粒子源的强度以及随空间的变化过程决定了是否能够发生蓄水池现象。更多还原

【Abstract】 The solar energetic particle(SEP)event has a great impact on human space activities.The study of SEP events helps to understand the physical mechanism of SEP accelerating and propagating in the heliosphere.Multi-spacecraft observations often reveal a interesting “reservoir” phenomenon: observers located at different longitudes,latitudes,and heliocentric distances among the interplanetary space see large differences in particle fluxes during the ascending phase of solar energetic particle events.But during the decay phase,the fluxes of the SEP are almost equal and evolve similarly over time.During different solar cycles,we combine spacecraft with different radial distances and longitudes at the ecliptic to observe the proton reservoir phenomenon of SEP events.Data comes from two Helios and IMP-8 spacecraft during the 21 st solar cycle,and STEREO A&B with SOHO spacecraft during the 23-24 th solar cycle.We found 24 proton reservoir events from more than 200 SEP events,and analyze the data.Base on the analysis of the observation results,we find that:(1)the larger peak value and the longer duration of SEP event,the more likely the reservoir phenomenon would occur.(2)The higher energy of SEP particles,the more likely the reservoir would occur.(3)In solar energetic proton event,if the two Helios spacecraft observe the reservoir phenomenon,basically this phenomenon would also appears in the IMP-8 observation;and the joint observations of STEREO A&B and SOHO also verifies this finding.Based on the above observations,we conclude that:(1)The forming of the ecliptic proton reservoir is dominated by shock,while the interplanetary perpendicular diffusion and magnetic mirror effects do not play a leading role.(2)Compare to lower energy particles,the injection process of higher energy particles mainly occurs near the Sun.In the process of particle injection,the intensity and the spatial changing of SEP source fuction determine whether the reservoir can occur.更多还原