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Role of non‐adiabatic processes in the creation of the outer radiation belts
Author(s) -
Fox Nicola J.,
Mauk Barry H.,
Blake J. Bernard
Publication year - 2006
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 - 10.1029/2006gl026598
Subject(s) - adiabatic process , van allen radiation belt , physics , radiation , electron , population , spacecraft , computational physics , magnetosphere , nuclear physics , astronomy , quantum mechanics , plasma , demography , sociology
Addressed here are characteristics of processes generating Earth's outer electron radiation region between ∼2 and 7 R E with electron energies from 100's of keV to greater than a few MeV. The question is: To what extent are non‐adiabatic processes required in the creation of the outer radiation belt from the purported source population, the plasmasheet residing beyond 10 R E ? Using data sampled within the plasmasheet by the ISEE‐1 satellite, we determine the phase space densities (PSDs) achievable by adiabatic transport processes alone from the plasmasheet and compare them with PSDs at various L‐values within the radiation belt, measured by the CRESS spacecraft. Because processes that might reduce transported PSDs are not included, the comparison yields a lower limit to the effects of non‐adiabatic processes. We find non‐adiabatic processes have a profound affect on outer radiation belt electrons with energies greater than ∼1 MeV, and most clearly between equatorial geocentric distances 5 to 7 R E .