Heliosphere-Geosphere Interactions Using Low Energy Neutral Atom Imaging
Heliosphere-Geosphere Interactions Using Low Energy Neutral Atom Imaging
复制标题
使用低能中性原子成像的日光层-地圈相互作用
DOI：
10.1007/978-94-010-0027-7_14
复制
发表时间：
2003
影响因子：
10.3
通讯作者：
M. Chandler
中科院分区：
文献类型：
--
作者：
T. Moore;M. Collier;M. Fok;S. Fuselier;H. Khan;W. Lennartsson;D. Simpson;G. Wilson;M. Chandler
开发低能中性原子(LENA)成像仪的最初动机是需要遥感电离层顶部的等离子体加热，目的是大大提高对一种原本熟悉的现象的时间分辨率。在地面测试和校准期间，Lena成像仪被发现对能量远高于其标称能量范围10-750电子伏特的中性原子做出响应，由于与其转换表面的溅射相互作用，能量高达至少3-4电子伏特。在轨道上，Lena被发现对太阳风中普遍存在的中性原子成分、高太阳风压期间磁鞘与地冕相互作用形成的中性原子以及在航天器和星际介质之间相对风速最大的季节流经日光层的星际中性原子做出反应。因此，Lena成像已成为研究行星际介质及其与磁层的相互作用以及这种相互作用所产生的电离层加热和外流的一种很有前途的新工具。来自电离层的Lena辐射由可在高海拔观测到的快速成分和明显产生准捕获扩展超热外圈的较慢成分组成。在几分钟的时间尺度上，能量越高的排放对太阳能风能输入的响应越快。
Development of the low energy neutral atom (LENA) imager was originally motivated by a need to remotely sense plasma heating in the topside ionosphere, with the goal of greatly enhanced temporal resolution of an otherwise familiar phenomenon. During ground test and calibration, the LENA imager was found to respond to neutral atoms with energies well above its nominal energy range of 10–750 eV, up to at least 3–4 keV, owing to sputtering interactions with its conversion surface. On orbit, LENA has been found to respond to a ubiquitous neutral atom component of the solar wind, to the neutral atoms formed by magnetosheath interactions with the geocorona during periods of high solar wind pressure, and to the interstellar neutral atoms flowing through the heliosphere during the season of maximal relative wind velocity between spacecraft and interstellar medium. LENA imaging has thus emerged as a promising new tool for studying the interplanetary medium and its interaction with the magnetosphere, in addition to the ionospheric heating and outflow that result from this interaction. LENA emissions from the ionosphere consist of a fast component that can be observed at high altitudes, and slower components that evidently create a quasi-trapped extended superthermal exosphere. The more energetic emissions are responsive to solar wind energy inputs on time scales of a few minutes.