Skip to Main content Skip to Navigation
Journal articles

Estimation of the Particle Radiation Environment at the L1 Point and in Near-Earth Space

Abstract : To characterize the particle radiation environment at the Lagrangian point L1 and in the near-Earth space we performed a systematic analysis of the particle flux data recorded by different instruments on board different spacecraft (ACE EPAM/LEMS120, IMP-8 CPME, and Geotail EPIC-ICS). We focused on protons in the poorly explored energy range ∼0.05-5 MeV, including energies of the so-called soft protons, which are critical for the Advanced Telescope for High Energy Astrophysics (ATHENA) mission, as well as the 145-440 MeV one, because high-energy particles affect all interplanetary missions. We estimated the energetic proton environment by computing the cumulative distribution functions for the different energy channels of each instrument and studied its variations with respect to solar activity. We obtained energetic proton spectra at cumulative probabilities (CPs) of 50% and 90% and worst-case scenarios, which can be used by the ATHENA mission for operational purposes and more generally for space weather hazards. We found an increase in the ∼0.05-5 MeV proton spectrum at 90% CP during the maximum phase of solar cycle (SC) No. 23 of about a factor from 3 to 5, depending on the energy, with respect to the overall period (1997-2014). Moreover, the 300-500 keV proton flux at 90% CP is higher during SC No. 21 by about a factor 1.5 and 3 compared to SC No. 22 and SC No. 23, respectively. Finally, variations with solar activity of the 145-440 MeV proton flux are within a factor of 2 at both 90% and 50% CPs, thus representing the low-energy galactic cosmic rays.
Complete list of metadata
Contributor : Nathalie POTHIER Connect in order to contact the contributor
Submitted on : Friday, May 20, 2022 - 3:33:38 PM
Last modification on : Monday, July 4, 2022 - 8:43:26 AM




M. Laurenza, T. Alberti, M. F. Marcucci, G. Consolini, C. Jacquey, et al.. Estimation of the Particle Radiation Environment at the L1 Point and in Near-Earth Space. The Astrophysical Journal, 2019, 873, ⟨10.3847/1538-4357/ab0410⟩. ⟨insu-03674455⟩



Record views