Simulation of a Soft-Gamma-ray Polarimeter on Board a Microsatellite

Gamma-ray polarimetry is a new and prospective tool for studying extremely high-energy celestial objects and is of great significance for the field of astrophysics. With the rapid development of microsatellite technology, the advantages of space exploration have become increasingly apparent. Therefore, we simulated a soft-gamma-ray polarimeter for a microsatellite based on the Compton scattering principle. We performed detailed Monte Carlo simulations using monoenergetic gamma-ray linear-polarization sources and Crab-like sources in the energy range of 0.1-10 MeV considering the orbital background. The polarimeter exhibited excellent polarization detection performance. The modulation factor was 0.80 +/- 0.01, and the polarization angles were accurate within an error of 0.2 degrees at 200 keV for on-axis incidence. For the Crab-like sources for on-axis incidence, the polarization degrees were consistent with the set values within the error tolerance, the modulation factor was 0.76 +/- 0.01, and the minimum detectable polarization reached 2.4% at 3 sigma for an observation time of 10(6) s. Additionally, the polarimeter exhibited recoil electron tracking, imaging, and powerful background suppression in a large field of view (FoV; similar to 2 pi sr). The proposed polarimeter meets the requirements of a space soft-gamma-ray polarization detector and has promising research prospects.