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

1. 用于观测木星同步辐射的接收系统已经研制成功。所研制的前置放大器满足最小检测灵敏度0.1 Junsky和接收机噪声温度75 K.2的要求。为准确探测木星辐射强度所必需的接收机校准系统已经研制完成。接收系统的相位和增益需要用环路法进行校准。实现的相对相位差补偿小于5.6，相对增益小于0.2 db。将研制的接收标定系统与大型天线系统对接，并进行了性能测试。结果表明，天线波束宽度和接收灵敏度均满足预期性能。成功地绘制了银河系327兆赫频率无线电波分布图。利用名古屋大学的木索和富士天文台的射电望远镜探测到了木星同步辐射的同时强度变化。木星同步辐射的详细观测是用34米的大碟形天线进行的。结果表明，在辐射增强过程中，相对论性电子具有高度的各向异性。同时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，观测到的射电通量增强是由于强烈的太阳UV/EUV事件加热了木星上层大气，从而增强了径向扩散造成的。利用三个航天器的数据研究了木星磁层释放的高能电子的变化。分析证实，木星上的电子受到木星位置上太阳风的动态压力的调制。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.