Investigation of electrons inside the satellite by the Geant4 simulation

Abstract

The measurement of the electron radiation inside the satellite is important for engineering and space environment researches. The particle radiation detectors (PRD) on board CBERS-1 and CBERS-2 made great contribution to understanding of the space environment. Then, what is the radiation relationship between inside and outside the satellite? The Monte Carlo simulation with Geant4 was implemented to study the problem. The boundaries of the energy bins of 0.5 and 2 MeV were precisely corresponding to outside energies of 0.99 and 2.52 MeV, respectively. Besides the changes of the energy bins, the fluxes inside were smaller than those of the corresponding bins outside. The spectrum inside the satellite was harder than that outside. An indicator was that the flux ratio of the high energy bin to the low energy bin increased more than 20% from outside to inside. The geometric factor (GF) relates to the incident energy of electrons. By using the AE-8 model to derive the incident spectrum, the GFs of the low and high energy bins were 1.15 and 0.70 cm² sr, respectively. GF of the low energy bin was larger than that of the high energy bin. But they were both smaller than the previous results. It was due to the scattering, straggle and shielding effects.