Mageis Observations in the Inner Magnetosphere

Abstract:

We examine two aspects of the 10’s of keV to MeV electron conditions in the inner magnetosphere. First is the observation of wave-particle interactions associated with substorm injections in the midnight to dawn region of the magnetosphere. Second is the electron content of the inner radiation zone and slot regions prior to and during storm times using background corrected MagEIS data. The wave-particle observations take advantage of the MagEIS high rate data mode in conjuction with the HOPE and EMFISIS burst mode data to show the tight relationship between the <70 keV electron fluxes and chorus waves. Both electron flux enhancements and flux depletions are observed during temporally localized chorus wave events.

The ability to remove the penetrating backgrounds caused by energetic protons in the inner zone and electron generated bremsstrahlung in the slot and outer zone allows one to put limits on the electron fluxes in these regions, especially for energies greater than a few hundred keV. We find that deep in the inner zone the electrons fluxes at >800 keV are very low or non-existent while there are significant fluxes of electrons at lower energies, down to MagEIS limit of ~30 keV. The more dynamic slot region fluxes have been similarly dominated by such lower energy electron fluxes thus far during the Van Allen Probes mission. We will also show evidence that during storm times the seed population electrons, <200 keV, can penetrate deep into the slot region and, at times, even into the inner zone.