Study on Jupiter's inner magnetosphere by the observation of Jovian synchrotron radiation

1.研制了木星同步辐射观测的接收系统。研制的前置放大器满足最低检测灵敏度为0.1 Junsky和接收机噪声温度为75 K的要求。探测木星辐射的准确强度所必需的接收器校准系统已经研制完成。接收系统的相位和增益变成使用环路方法来校准。实现的相对相位差补偿小于5.6，相对增益小于0.2 dB。将研制的接收校准系统接入大型天线系统，进行了性能测试。经验证，天线波束宽度和接收灵敏度均满足预期性能。成功制作了频率为327 MHz的银河系无线电波分布图.利用名古屋大学木曾天文台和富士天文台的射电望远镜探测到木星同步辐射的同时强度变化。使用34米的大型碟形天线对木星同步辐射进行了详细的观测。结果表明，在辐射增强过程中，相对论电子呈现出高度的各向异性。还发现了辐射与太阳10.7通量之间的相关性。模型模拟表明，观测到的无线电通量增强是由强烈的太阳紫外/极紫外事件加热木星上层大气引起的增强的径向扩散造成的。利用三个航天器的观测数据研究了木星磁层释放高能电子的变化。分析证实，木星电子受到木星位置太阳风动态压力的调制。研究还发现，高能电子的释放速率受IMF极性的控制。

1. The receiving system for the observation of Jupiter's synchrotron radiation has been developed. The developed pre-amplifier satisfies the demands of the minimum detection sensitivity of 0.1 Junsky and receiver noise temperature of 75 K.2. The calibration system for the receiver, which is necessary to detect the accurate intensity of Jupiter's radiation, has been developed and completed. The phase and gain of the receiving system becomes to be calibrated using the loop method. The achieved compensation of the relative phase difference was less than 5.6, and relative gain was less than 0.2 dB.3. The developed receiving and calibration system was connected to the large antenna system, and the performance test was carried out. It was confirmed that both the antenna beam width and receiving sensitivity satisfy the expected performance. The distribution map of the Galactic radio waves at a frequency of 327 MHz was successfully produces.4. The simultaneous intensity variation of Jupiter's synchrotron radiation has detected using the radio telescopes of Kiso and Fuji Observatories, Nagoya University.5. Detailed observations of Jovian synchrotron radiation was carried out using the 34 m large dish antenna. It was shown that the relativistic electrons were highly anisotropy during the radiation was enhanced. The correlation between the radiation and the solar 10.7 flux was also detected. A model simulation suggested that the observed radio flux enhancement was caused by the enhanced radial diffusion due to the intense solar UV/EUV event which heated the Jupiter's upper atmosphere.6. Variations of energetic electrons released from the Jovian magnetosphere are investigated by using data from three spacecraft. Analyses confirmed that the Jovian electrons are modulated by the dynamic pressure of the solar wind at the position of Jupiter. It is also found that the release rate of energetic electrons is controlled by the polarity of IMF.