Abstract
Since more than 15 years, the Cluster mission passes through Earth's radiation belts at least once every 2 days for several hours, measuring the electron intensity at energies from 30 to 400 keV. These data have previously been considered not usable due to contamination caused by penetrating energetic particles (protons at >100 keV and electrons at >400 keV). In this study, we assess the level of distortion of energetic electron spectra from the Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) detector, determining the efficiency of its shielding. We base our assessment on the analysis of experimental data and a radiation transport code (Geant4). In simulations, we use the incident particle energy distribution of the AE9/AP9 radiation belt models. We identify the Roederer L values, L*, and energy channels that should be used with caution: at 3 <= L* <= 4, all energy channels (40-400 keV) are contaminated by protons (similar or equal to 230 to 630 keV and >600 MeV);at L* similar or equal to 1 and 4-6, the energy channels at 95-400 keV are contaminated by high-energy electrons (>400 keV). Comparison of the data with electron and proton observations from RBSP/MagEIS indicates that the subtraction of proton fluxes at energies similar or equal to 230-630 keV from the IES electron data adequately removes the proton contamination. We demonstrate the usefulness of the corrected data for scientific applications.
Item Type: | Journal article |
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Faculties: | Geosciences > Department of Earth and Environmental Sciences |
Subjects: | 500 Science > 550 Earth sciences and geology |
ISSN: | 1542-7390 |
Language: | English |
Item ID: | 48870 |
Date Deposited: | 27. Apr 2018, 08:16 |
Last Modified: | 04. Nov 2020, 13:26 |