Fundamental technical development of the detector system of the solar resonance scattering light by analyzing the ion density and velocity distribution

通过分析离子密度和速度分布进行太阳共振散射光探测器系统的基础技术开发

基本信息

批准号：
07640585
负责人：
IWAGAMI Naomoto
金额：
$ 1.47万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

We studied the possibility to image the oxygen ions which exist in the Earth's magnetotail. As we had had no knowledge of the existence of the oxygen ions in the tail region of the Earth's magnetosphere until several years before, the GEOTAIL spacecraft, which serches for the magnetosphere, identified the oxygen ions with very low temperature and high density. These oxygen ions flow as a beam from the Earth to the tail direction, whose velocity becomes higher as more distant. We will make big progress in studying the dynamics of the magnetosphere, if we can take picutres of the whole magnetosphere by using oxygen ions. The wavelength of the resonant scattering light is subject to the Doppler shifting, as the oxygen ions move relatively to the Sun. The efficiency of the resonant scatter becomes worse when ions are largely Doppler shifted because the width of the resonant scattering lines is several tens of milli-angstrom and the emission line width of the sun light is the same order to … More this. Resonant scatter does not occur essentially to the single emission line as helium, when relative velocity becomes over 50km/sec. Oxygen ions, on the other hand, have three resonant scattering lines which are very close to each other. There are 9 emission lines corresponding to the (singly and doubly ionized) oxygen ion in the solar light, so Oxygen ions can scatter another emission line resonantly when they are subjected to the Doppler shifting by the relative motion. We calculated the geometric factor which show the efficiency of the resonant scatter considering this effect. Also, we simulated the intensity of the scattered light from the tail region of the magnetosphere by the oxygen ions by using the model of the velocity, temperature and density of the oxygen ions from the results of the GEOTAIL spacecraft. Using these values, we concluded that the intensity of the light is 0.1-10 Rayleigh. The result means that we can image the Earth's magnetosphere with the resolution of 1 Re (Earth's radius) by using 25 cm diameter telescope, exposing about 10 minutes. Thus our study show the imaging of the magnetotail is possible in principle. Less

我们研究了成像地球磁尾中存在的氧离子的可能性。由于我们对地球磁层尾部的存在不了解，直到几年前，用于磁层的岩土航天器的岩土航天器鉴定出非常低的温度和高密度的氧离子。这些氧离子从地球流动到尾部方向，其速度变得更高。如果我们可以使用氧气离子捕获整个磁层的piSutres，我们将在研究磁层的动力学方面取得巨大进展。随着氧离子相对向太阳移动，谐振散射光的波长会受到多普勒的转移。光是相同的顺序……更多。当相对速度超过50km/sec时，共振散射本质上并不是单发线作为氦气。另一方面，氧气离子具有三个彼此非常近的谐振散射线。有9个发射线对应于太阳光中（单一和双重离子化的）氧离子，因此当氧离子经过相对运动的多普勒移动时，氧离子可以散射另一个发射线。我们计算了几何因素，该几何因素显示了这种效果，该因子显示了谐振散射的效率。同样，我们使用氧气离子的模型从岩土飞船的结果中使用了氧气，温度和密度的模型，通过氧气模拟了磁层尾部的散射光强度。使用这些值，我们得出结论，光的强度为0.1-10雷利。结果意味着我们可以使用直径25 cm的望远镜，以1 RE（地球半径）的分辨率对地球的磁层进行成像，暴露约10分钟。我们的研究表明，原则上可以表明磁尾的成像。较少的