Study of wave-particle interactions in space plasmas (Joint research using multiple spacecraft observations and computer experiments)

由于发射失败，我们错过了集群航天器。然而，我们成功地进行了GEOTAIL、WIND、POLAR、FREJA和Akebono航天器之间的合作。我们利用GEOTAIL和WIND同时观测了III型太阳射电爆发和2FP辐射，分析了III型太阳射电爆发的传播特征和2FP辐射的源位置。此外，在AKR排放方面，我们通过GEOTAIL、WIND航天器和光线追踪数值计算的合作，发现其来源位于21-22MLT。GEOTAIL、WIND和FREJA航天器分别在尾部、太阳风和极区观测到调制的朗缪尔波。许多解释这些幅度调制的理论尝试都集中在非线性波-波耦合上，然而，它们还没有成功。我们的计算机实验成功地再现了这些被调制的朗缪尔波的波形，并表明所观察到的幅度调制是由于没有波-波相互作用的捕获效应而引起的朗缪尔波的空间调制的结果。在Akebono、Freja航天器和射线追踪的合作中，我们发现极光Hiss的源区位于极地地区11000公里的高度。我们研究了与观测到的静电孤立波相对应的电子速度分布。我们发现高能电子的存在与ESW场是同向流动的，这一结果与对应于电子束不稳定性最后阶段的BGK势模型是一致的。

Due to the launch failure, we missed the CLUSTER spacecraft. However, we succeeded to proceed the collaboration among GEOTAIL,WIND,POLAR,Freja, and AKEBONO spacecraft. We performed the simultaneous observations of the Type III solar radio bursts, and 2 fp emissions by GEOTAIL and WIND and we analyzed the propagation features of the Type III solar radio bursts and the source location of the 2 fp emissions. Further, on the AKR emissions, we showed that its source is located at 21-22 MLT based on the collaboration among GEOTAIL,WIND spacecraft and Ray tracing numerical calculations. The modulated Langmuir waves are observed in the tail, solar wind, and polar regions by GEOTAIL,WIND,and Freja spacecraft, respectively. Many theoretical attempts to explain these amplitude modulations have focused on the nonlinear wave-wave coupling, however, they have not succeeded, yet. Our computer experiments succeeded to reproduce the waveforms of these modulated Langmuir waves and showed that the observed amplitude modulations are the result of the spatial modulation of the Langmuir waves due to the trapping effects without the wave-wave interactions. In the collaboration among AKEBONO,Freja spacecraft and the ray tracing, we found that the source region of the Auroral Hiss is located at 11,000km altitude in the polar region. We examined electron velocity distributions corresponding to the observations of the electrostatic solitary waves (ESW). We found the existence of the high energy electrons streaming in the same direction with the ESW.This result is consistent with the BGK potential model which corresponds to the final stage of electron beam instabilities.