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Electron Pitch Angle Distributions Around Dipolarization Fronts at the Off Magnetic Equator
Author(s) -
Tang C. L.,
Wang X.,
Zhou M.
Publication year - 2021
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2020ja028787
Subject(s) - betatron , physics , pitch angle , electron , equator , magnetic dip , acceleration , fermi gamma ray space telescope , computational physics , fermi acceleration , atomic physics , particle acceleration , astrophysics , nuclear physics , classical mechanics , geophysics , latitude , astronomy
The pitch angle distributions of energetic electrons (10 s–200 keV) around the dipolarization front (DF) have been studied extensively. However, the pitch angle distributions of energetic electrons around the DF at the off magnetic equator have been unclear so far. In this study, we present the observations of the DF at the off magnetic equator in the near‐Earth tail. Some properties of the DF at the off magnetic equator are presented. Importantly, the triple‐peaked pitch angle distribution of energetic electrons around the DF is found. Such a new type of distribution is a peak at around 22.5°, 90°, and 157.5°, which is a combinational consequence of betatron acceleration, Fermi acceleration, and magnetic mirror effect. Using an analytical model, we quantitatively reproduce the processes of betatron acceleration, Fermi acceleration, and magnetic mirror effect. These results will further enhance our understanding of the electron dynamics around DFs.