| タイトル | Radial evolution of solar wind thermal electron distributions due to expansion and collisions |
| 著者（英） | Gosling, J. T.; Phillips, J. L. |
| 著者所属（英） | Los Alamos National Lab. |
| 発行日 | 1990-04-01 |
| 言語 | eng |
| 内容記述 | ISEE 3 electron observations near 1 AU show that the solar wind thermal electron temperature anisotropy, T(parallel)/T(perpendicular), is typically 1.0 to 1.5, with densest distributions most nearly isotropic, but is sometimes much higher when density is low. For a small observational subset characterized by high density and low bulk speed, T(perpendicular) can exceed T(parallel). Based on these and other observations, a simple model is proposed for radial evolution of thermal electrons in a structureless solar wind under the influence of Coulomb collisions and geometric expansion in a spiral interplanetary magnetic field. The model, which satisfactorily explains the 1 AU observations, shows that the evolution of electron temperature and T(parallel)/T(perpendicular) is controlled by plasma density, flow speed, and initial temperature, with density the most important factor. The model makes predictions for radial distances other than 1 AU and for high solar latitudes. |
| NASA分類 | SOLAR PHYSICS |
| レポートNO | 90A30563 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/356956 |
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