Energy response and in-flight background simulationfor GECAM
D. Y. Guo, JinYuan LIAO, Sheng Yang, XinQiao LI, Xilei Sun, WenXi PENG, Rui Qiao, Yue Zhu, Zhenghua An, Gang Li, DaLi ZHANG, ShaoLin XIONG, YanBing XU
Abstract
<p indent="0mm">The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is designed to detect gravitational wave gamma-ray bursts and other high-energy transient sources in the energy range of <sc>6 keV–5 MeV.</sc> It has the characteristics of all-sky field of view, high sensitivity, good positioning accuracy and wide band coverage. The mission consists of two satellites with each containing 25 gamma-ray detectors (GRD) and 8 charged particle detectors. In this paper, the energy response matrix and in-flight background of each GECAM detector are obtained by Geant4 simulation. The simulation results show that the GECAM has stronger observation ability than the Fermi/GBM in low-energy range. The average in-flight background of a single GRD is about <sc>800 cps,</sc> and there are three characteristic peaks that can be used for on-orbit calibration.