Exploring the Efficiency of HEPD-02 LYSO:Ce Scintillators in the CSES-02 Satellite Mission for Detecting Gamma-Ray Bursts

The CSES-02 satellite mission seeks to expand our knowledge of the interconnection between the Earth's lithosphere, atmosphere, ionosphere, and magnetosphere. Various instruments will measure the electromagnetic environment around the satellite, which will fly in a Sun-synchronous orbit at approximately 500 km from the ground. The HEPD-02 payload, developed by the Italian Limadou collaboration, is a fundamental component of the mission. It measures the flux of protons (30 to 200 MeV) and electrons (3 to 100 MeV) trapped in the Van Allen Belts, representing an indispensable instrument for studying the ionosphere and the magnetosphere. The HEPD-02 payload mounts LYSO:Ce scintillating crystals to measure the energy of impinging particles. Limadou chose LYSO:Ce due to its fast decay time (40ns), high density (7.1 g/cm3) and high light yield (about 30000 ph/MeV). The module made of LYSO crystals and its relative acquisition system will be sensitive to Gamma-Ray Bursts of energy larger than 2 MeV, a range currently covered by experiments like HXMT, Fermi, and INTEGRAL. With an optimal energy resolution, HEPD-02 will contribute to expanding the coverage of the sky for the detection and study of GRBs. We will report on the sensitivity of HEPD-02 to short and long GRBs, obtained with an Elekta medical LINAC model SL15.