The development of a high granular crystal calorimeter prototype of VLAST
Yanshuo Zhang, Qian Chen, Dengyi Chen, Jianguo Liu, Yiming Hu, Yunlong Zhang, Yifeng Wei, Zhongtao Shen, Changqing Feng, Jianhua Guo, Shubin Liu, Guangshun Huang, Xiaolian Wang, Zizong Xu
Published: 2025/9/29
Abstract
Very Large Area gamma-ray Space Telescope (VLAST) is the next-generation flagship space observatory for high-energy gamma-ray detection proposed by China. The observation energy range covers from MeV to TeV and beyond, with acceptance of 10 m^2sr. The calorimeter serves as a crucial subdetector of VLAST, responsible for high-precision energy measurement and electron/proton discrimination. This discrimination capability is essential for accurately identifying gamma-ray events among the background of charged particles. To accommodate such an extensive energy range, a high dynamic range readout scheme employing dual avalanche photodiodes (APDs) has been developed, achieving a remarkable dynamic range of 10^6. Furthermore, a high granular prototype based on bismuth germanate (BGO) cubic scintillation crystals has been developed. This high granularity enables detailed imaging of the particle showers, improving both energy resolution and particle identification. The prototype's performance is evaluated through cosmic ray testing, providing valuable data for optimizing the final calorimeter design for VLAST.