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Van Allen Probes show that the inner radiation zone contains no MeV electrons: ECT/MagEIS data
Author(s) -
Fennell J. F.,
Claudepierre S. G.,
Blake J. B.,
O'Brien T. P.,
Clemmons J. H.,
Baker D. N.,
Spence H. E.,
Reeves G. D.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062874
Subject(s) - electron , van allen radiation belt , physics , atomic physics , van allen probes , ion , radiation , plasma , nuclear physics , magnetosphere , quantum mechanics
We present Van Allen Probe observations of electrons in the inner radiation zone. The measurements were made by the Energetic Particle, Composition, and Thermal Plasma/Magnetic Electron Ion Spectrometer (MagEIS) sensors that were designed to measure electrons with the ability to remove unwanted signals from penetrating protons, providing clean measurements. No electrons >900 keV were observed with equatorial fluxes above background (i.e., >0.1 el/(cm 2 s sr keV)) in the inner zone. The observed fluxes are compared to the AE9 model and CRRES observations. Electron fluxes <200 keV exceeded the AE9 model 50% fluxes and were lower than the higher‐energy model fluxes. Phase space density radial profiles for 1.3 ≤ L * < 2.5 had mostly positive gradients except near L *~2.1, where the profiles for μ = 20–30 MeV/G were flat or slightly peaked. The major result is that MagEIS data do not show the presence of significant fluxes of MeV electrons in the inner zone while current radiation belt models and previous publications do.