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Charged Particle Distribution in the Nearest Vicinity of Ionospheric Satellites-Comparison of the Main Results from the Ariel I, Explorer 31 and Gemini-Agena 10 Spacecraft

1973; Springer Nature (Netherlands); Linguagem: Inglês

10.1007/978-94-010-2647-5_12

2214-7985

U. Samir,

Geomagnetism and Paleomagnetism Studies

Electron and ion measurements performed by probes mounted on the Ariel I, the Explorer 31 and the Gemini-Agena 10 spacecraft which reflect on some aspects of the interaction between a spacecraft and its ionospheric plasma are compared. A partial picture of charged particle distributions around surfaces in space is thereby obtained. Results from the above satellites are compared among themselves and the degree of agreement/disagreement is demonstrated. Comparisons of results with some wake models are included, and the degree of agreement is discussed.It is found that at the closest vicinity to the spacecraft surface and for space plasmas with high hydrogen concentration (H+) Explorer 31 results agree with the Gurevich et al. wake model. For situations were O+ is the major ionic constituent the agreement excludes the entire region of maximum rarefaction. Comparison of results from the spherical ion probe on the Explorer 31 satellite indicate that plasma neutrality in the wake region is reached at fairly close distances (r ≃ 2R 0) for conditions that prevail in the ionosphere at altitudes of 400–700 km. Comparing Ariel I and Explorer 31 results for the electron angular distribution close to the surface of the satellite with results from the Agena 10 maneuver shows good agreement. This is not in line with a priori expectations. The degree of agreement between the Explorer 31 results for the electron angular distribution in the closest vicinity to the satellite surface shows reasonable agreement with the Liu-Jew wake model. This is in a way surprising due to shortcomings of the theory and limitations of the comparison procedure itself. Results of both ion electron fluxes from the Explorer 31 satellite yield quantitatively the net current around the satellite. Wakes created by bodies of different size and surface potentials are quantitatively examined.