Energy-banded ions in Saturn's magnetosphere

Thomsen, M. F. and Badman, Sarah Victoria and Jackman, Caitriona M. and Jia, X. and Kivelson, Margaret G. and Kurth, W.S. (2017) Energy-banded ions in Saturn's magnetosphere. Journal of Geophysical Research: Space Physics, 122 (5). pp. 5181-5202. ISSN 2169-9402

[thumbnail of Energy-Banded Ions v4 combined]
PDF (Energy-Banded Ions v4 combined)
Energy_Banded_Ions_v4_combined.pdf - Accepted Version
Available under License Creative Commons Attribution-NonCommercial.

Download (11MB)
[thumbnail of Thomsen_et_al-2017-Journal_of_Geophysical_Research-_Space_Physics]
PDF (Thomsen_et_al-2017-Journal_of_Geophysical_Research-_Space_Physics)
Thomsen_et_al_2017_Journal_of_Geophysical_Research_Space_Physics.pdf - Published Version

Download (4MB)


Using data from the Cassini Plasma Spectrometer ion mass spectrometer, we report the first observation of energy-banded ions at Saturn. Observed near midnight at relatively high magnetic latitudes, the banded ions are dominantly H+, and they occupy the range of energies typically associated with the thermal pickup distribution in the inner magnetosphere (L < 10), but their energies decline monotonically with increasing radial distance (or time or decreasing latitude). Their pitch angle distribution suggests a source at low (or slightly southern) latitudes. The band energies, including their pitch angle dependence, are consistent with a bounce-resonant interaction between thermal H+ ions and the standing wave structure of a field line resonance. There is additional evidence in the pitch angle dependence of the band energies that the particles in each band may have a common time of flight from their most recent interaction with the wave, which may have been at slightly southern latitudes. Thus, while the particles are basically bounce resonant, their energization may be dominated by their most recent encounter with the standing wave.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Geophysical Research: Space Physics
Additional Information:
An edited version of this paper was published by AGU. Copyright 2016 American Geophysical Union. Copyright 2017 American Geophysical Union. Further reproduction or electronic distribution is not permitted. Thomsen, M. F., S. V. Badman, C. M. Jackman, X. Jia, M. G. Kivelson, and W. S. Kurth (2017), Energy-banded ions in Saturn's magnetosphere, J. Geophys. Res. Space Physics, 122, doi:10.1002/2017JA024147
ID Code:
Deposited By:
Deposited On:
05 May 2017 08:34
Last Modified:
14 Jul 2024 01:22