Study on Particle Acceleration in Solar Flares with HESSI, "Yohkoh," and Nobeyama Radioheligograph

本研究旨在通过RHESSI和Yohkoh卫星的X射线和γ射线图像与野边山射电日像仪的射电图像的详细比较，揭示太阳耀斑粒子加速机制。为了实现这一目标，我们首先（i）为RHESSI开发MEM图像合成软件工具，评估所得RHESSI图像的质量，并编辑了Yohkoh观测到的耀斑目录，然后（ii）进行观测和理论研究。主要成果如下：1.发表了基于Yohkoh观测的耀斑研究综述; 2.详细分析了共轭硬X射线足点源相对于磁中性线的水平运动，建立了日冕磁场重联的三维模型; 3.通过理论和数值研究，提出了基于Betatron机制的重联、坍缩磁环中高能电子的激发和俘获新方案。

This study aims at unveiling the solar flare particle acceleration mechanism by detailed comparison of X-ray and gamma-ray images taken from RHESSI and Yohkoh satellites with radio images from Nobeyama Radioheliograph. In order to attain this goal, we first (i)developed MEM image synthesis software tools for RHESSI, evaluate the quality of resultant RHESSI images, and edited a catalogue of flares that Yohkoh observed, and then (ii)conducted observational and theoretical research. Essences of scientific achievement can be summarized as follows :1.A review paper of solar flare research basing upon the Yohkoh observations was published.2.Conducting detailed analysis of horizontal motions of the conjugate, hard X-ray footpoint sources with respect to the magnetic neutral line, we constructed a 3-d model of magnetic reconnection in the solar corona.3.From a theoretical and numerical study, we proposed a new scenario for energizing and trapping high-energy electrons in reconnected, collapsing magnetic loops due to the Betatron mechanism.