Studies on production processes of exospheric atmospheres of Mercury and Io based on development of a spectro-imager

1.外大气二维光谱成像系统的研制了一套用于探测行星和卫星外大气钠辐射的光谱成像系统。该系统由1）由光纤束制成的尺寸转换光学器件和2）将尺寸转换光学器件连接到光入射和出射光学器件的F数调节光学器件组成。光纤束布置为12 x12（入口）和144 x1（出口）。该系统设置在光学工作台上，并连接到东北大学的60 cm直径Coude望远镜（入口侧）和高分辨率光栅光谱仪（出口侧）。将光谱数据投影到Li-N2致冷的CCD相机上，在计算机上重建成光谱图像.利用光谱成像系统对伽利略卫星之一的木卫一和水星的外大气层进行了观测。有人说，生产 关于我们 木卫一大气层的速率取决于木卫一的相位角（木卫一相对于木星的视位置）。为了证实这种依赖关系，我们对不同相角的木卫一进行了观测，得到了有意义的数据集。另一方面，水星的观测是在水星与太阳大部分分离的时期进行的。由于主要是恶劣的天气条件下，可靠的图像调查天然气生产过程中没有得到充分的研究期间。我们计划在2006年6月之后进行后续观测，那时水星在2006年与太阳的距离最大。开发了一个蒙特-卡罗模拟模型，并将其用于天然气开采过程的研究。作为水星大气层的结果，它表明，太阳风质子的离子溅射比以前预测的水星表面更有效地操作，以产生大气层。对于木卫一的大气层，推测其数量可能是由木星磁层等离子体的溅射和/或窥视与太阳光的光子激发解吸的耦合过程控制的。少

1. Development of a 2D spectro-imaging system for exospheric atmospheresA spectro-imaging system for detection of sodium emissions of exospheric atmospheres of planets and satellites is developed. The system consists of 1)a dimension converting optics made of an optical fiber bundle, and 2)a F-number adjusting optics to connect the dimension converting optics to light-entrance and exit optics. The optical fiber bundle is arranged in 12x12(entrance) and 144x1(exit). The system is set up on an optical bench and connected to the 60cm diameter coude telescope (entrance side) and high-resolution grating spectrometer (exit side) of Tohoku University. A spectrum datum is projected onto a Li-N2 cooled CCD camera and reconstructed to a spectro-image on a computer.2. Observations of exospheric atmospheres of Io and MercuryObservations of exospheric atmospheres of Io, one of the Galilean satellites, and Mercury have been made using the spectro-imaging system. It has been suggested that production … More rate of Io's atmosphere depends on Io's phase angel (Io's apparent position with respect to Jupiter). In order to confirm the dependence, we have made observations of Io for various Io's phase angles and obtained significant data-sets. On the other hand, Mercury observations have been made intensively for the period when Mercury is viewed largely apart from the sun. Due to bad weather condition in main, reliable images for investigating gas production processes have not been sufficiently acquired in the research period. We plan to make follow-up observations after June, 2006 when Mercury is viewed most largely apart from the sun in 2006.3. Numerical simulation for investigating gas production processesA Monte-Carlo simulation model has been developed and adopted for the investigations of gas production processes. As the result for Mercury's atmosphere, it is suggested that ion sputtering by solar wind protons is operated further more effectively than previously predicted on Mercury's surface to product the atmosphere. As for Io's atmosphere, it is inferred that the amount of the atmosphere might be controlled by the coupling process of sputtering and/or peering by Jupiter's magnetospheric plasma and the photon stimulated desorption by the sunlight. Less