Ions Accelerated by Sounder‐Plasma Interaction as Observed by Mars Express. Issue 11 (22nd November 2018)

• Record Type: Journal Article
• Authors: Voshchepynets, A.; Barabash, S.; Ramstad, R.; Holmstrom, M.; Andrews, D.; Nicolaou, G.; Frahm, R. A.; Kopf, A.; Gurnett, D.
• Is Part Of: Journal of geophysical research. Volume 123:Issue 11(2018)
• Page Start: 9802
• Page End: 9814
• Publication Date: 2018-11-22
• Subjects: Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2018JA025889
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: The ion sensor of the Analyzer of Space Plasmas and Energetic Atoms (ASPERA‐3) experiment detects accelerated ions during pulses of radio emissions from the powerful topside sounder: the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) onboard Mars Express. Accelerated ions (O 2 +, O +, and lighter ions) are observed in an energy range up to 800 eV when MARSIS transmits at a frequency close to the plasma frequency. Individual observations consist of almost monoenergetic ion beams aligned with the MARSIS antenna or lying in the plane perpendicular to the antenna. The observed ion beams are often accompanied by a small decrease in the electron flux observed by the electron sensor of Analyzer of Space Plasmas and Energetic Atoms 3. Observations indicate that the voltage applied to the antenna causes charging of the spacecraft to several hundreds of volts by the electrons of the ambient plasma. Positively charged ions are accelerated when the spacecraft discharges. Key Points: Accelerated ions are detected by IMA of ASPERA‐3 during sounding phase of MARSIS radar The energy of accelerated ions is found to be in a range of 20 to 800 eV Observations coincide in time with periods when MARSIS transmits close to the plasma frequency