Carbon dioxide photoelectron energy peaks at Mars
- 作者：R.A. Frahm ; J.D. Winningham ; J.R. Sharber ; J.R. Scherrer ; S.J. Jeffers ; A.J. Coates ; D.R. Linder ; D.O. Kataria ; R. Lundin ; S. Barabash et al.
- 关键词：Mars ; Ionospheres ; Atmospheres ; Magnetospheres
- 刊名：Icarus
- 出版年：2006
- 期刊代码：90_00191035
- 类别：ph
- 出版时间：June 2006
- 卷：182
- 期：2
- 页码：371-382
- 文件大小：769 K
摘要
The ELectron Spectrometer (ELS) from the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) flown on the Mars Express spacecraft has an 8%energy resolution, combined with the capability to oversample the martian electron distribution. This makes possible the resolution and identification of electrons generated as a result of the He 304 Å ionization of CO<sub>2sub> at the martian exobase on the dayside of the planet. Ionospheric photoelectrons were observed during almost every pass into the ionosphere and CO<sub>2sub> photoelectron peaks were identified near the terminator. Atmospherically generated CO<sub>2sub> photoelectrons are also observed at 10,000 km altitude in the martian tail near the inner magnetospheric boundary. Observations over a wide range of spacecraft orbits showed a consistent presence of photoelectrons at locations along the inner magnetospheric boundary and in the ionosphere, from an altitude of 250 to 10,000 km.