【作者】 钟晓春；

【导师】 王蜀娟；

【作者基本信息】 西南交通大学 ， 理论物理， 2003， 硕士

【摘要】 太阳活动密切地影响着日地空间环境和地球高空大气结构，太阳耀斑爆发产生的日冕物质抛射(CME)是空间灾害的主要原因之一。探索太阳活动的规律、太阳耀斑及其伴随CME的先兆、触发过程及能量传播机制等等，从理论上推动了等离子体天体物理、磁流体力学等诸多基础理论的发展，有着重要的理论意义；而对太阳活动的预报，是国际前沿科学—空间天气学的重要组成部分，对避免空间灾害、为航空航天科学提供服务等方面，具有重大的实际应用价值。著名的“微耀斑理论”，试图从较小的时间、空间尺度范围探究太阳耀斑形成和触发的基本单元，而射电精细结构是微耀斑理论的重要观测基础，对射电精细结构的观测和理论研究已成为太阳射电天文学中快速发展的领域，对揭示太阳活动源区的物理本质具有重要的意义。 2000年7月14日的太阳耀斑爆发—Bastille事件，备受国际太阳物理学家关注，著名的SCI刊物“Solar Physics”特出版专辑研讨该事件，从光球、色球、日冕、直至日地空间的广阔空间尺度范围内，对该事件的观测资料进行了分析和理论研究。中国国家天文台怀柔观测站的宽带频谱射电望远镜，观测到了来自内日冕区的射电爆发及其精细结构，携带着耀斑爆发初期磁场变化、能量释放的丰富信息，很有必要对其进行深入的理论分析和计算。 作者在调研国内外太阳射电爆发研究的基础上，分析国家天文台射电望远镜观测到的Bastille事件的射电爆发资料。对叠加于太阳射电Ⅳ型爆发上的精细结构，作出了观测特征分析，发现大多数纤维结构的观测特征在米波段和分米波段是相似的，由此提出它们可能源于相似的辐射机制，并采用磁镜环模型，首次对分米波段的纤维结构进行分析计算，推算了纤维辐射源区磁场强度大小及辐射源的空间尺度，且相关物理参量的推算量级与其他人的研究工作结果是一致的，从而对该爆发源区的物理环境及过程有了进一步深入的认识。 本论文首先概述了太阳活动、太阳射电研究历史及现状、射电辐射理论等相关背景知识；其次，详细处理、分析和描述了Bastille事件的射电 西南交通大学硕士研究生学位论文 第11页观测资料，统计分析其典型的观测特征；再次，阐述了与模型相关的基础理论，包括磁流管特性、磁场重联、等离子体波及波一波相互作用等：然后，针对Bastile事件的射电纤维精细结构，详细分析了在其辐射源区可能发生的等离子体加速过程，以及不稳定性导致的孤波，并对磁场强度及辐射源的空间尺度等进行了估算，结果与其他理论预期相吻合：最后，对本研究结果进行了总结和讨论。更多还原

【Abstract】 Solar activity, especially, Coronal Mass Ejection (CME) during a large solar activity affected the space environment of human being and could be one of main reasons of the space disaster. Theoretical researches on solar activity, solar flare and CME were involved in many fields of foundational physics such as plasma astrophysics, magnetohydrodynamics (MHD) and so on. The forecast of solar activity, a main branch of Space Weather, was becoming more and more significant for preventing space disaster and for many aspects of space science. Furthermore the ’microflare theory’ tried to discuss and find the elementary flares in small space and time scale which might form and trigger the whole solar flare. The detection of radio fine structures showed many observational evidences of ’microflare’. The observations and theoretical researches on radio fine structure have been developed fast recently and played an important role in solar radio astrophysics.The Bastille-Day flare of 14 July 2000, a great solar flare with X-ray/Ha importance of X5.7/B3, was observed around 10:24 UT in the NOAA 9077 AR at position N22W07. In this flare, very rich interesting radio bursts and fine radio spectral structures were detected, not only in metric wave band, but also in decimetric and microwave band (1.0-7.6 GHz by National Astronomical Observatories of Chinese Academy of Sciences - NAOC). The event gave us a good opportunity to discuss the processes of magnetic change, energy release and particle acceleration in the corona during the preflare, especially using decimetric and microwave fine structure data.In this thesis, we report the solar type IV bursts and its associated fiber fine structures recorded on 14 July 2000. A theoretical interpretation for the fibers is based upon the model of a magnetic-mirror loop configuration in the solar corona. In this model, the source of the fiber emission is considered as the ducting of whistler solitons within the magnetic-mirror loop. Using this model, we estimate the magnetic field strength and the relevant space scale of the emission source area.In Chap.1 of this dissertation, we introduce the background of solar activity, solar radio research and radio emission theory. In Chap.2, the observational characteristics of the radio burst of the Bastille event were discussed in detail. In Chap.3, we described the associated foundational theories with the model of a magnetic-mirror loop, consisting of the flux duct, the magnetic reconnection, the plasma wave, the wave-wave interaction and so on. Then in Chap.4, using the model of magnetic-mirror loop to estimate quantitatively, we obtain the magnetic field strength, the number of solitons in a single fiber source, the volume of the source and the ducting parameters. Finally we give out some conclusions and discussions.更多还原