Design and preliminary performance study of the broad-band spectrometer detector for POLAR-2
Abstract
POLAR-2, the successor of the POLAR experiment aboard China's Tiangong-2 space lab, is set to be deployed on the China Space Station. The POLAR-2 mission aims to conducting high-precision polarization measurements of high-energy transients with a primary focus on Gamma-Ray Bursts (GRBs), following POLAR's pioneering accurate polarization measurements of GRB prompt emission. One of the key advancements in POLAR-2 is the inclusion of a dedicated Broad-band Spectrometer Detector (BSD) instrument, designed to provide precise measurements of GRB location and spectral parameters, which are critical inputs for accurate polarization analysis of POLAR-2's dedicated High-energy Polarimetry Detector (HPD), which is made of plastic scintillator bars array. BSD employs a coded-aperture mask imaging technique and pixelated GAGG scintillation crystals, offering a wide half-coded field of view of ~132{\deg} x 125{\deg} and an operational energy range of 10-1000 keV. Simulation results indicate that the instrument can achieve a localization accuracy of approximately 1.5{\deg} for faint GRBs similar to GRB 170817A, satisfying the core requirements of GRB polarimetry with HPD. BSD also has moderate capability for GRB polarimetry, particularly at several hundred keV energy. This paper outlines the preliminary design of BSD and presents an overall evaluation of its expected scientific performance, based on extensive Monte Carlo simulations and preliminary ground-based calibration tests.
Keywords
Cite
@article{arxiv.2604.19497,
title = {Design and preliminary performance study of the broad-band spectrometer detector for POLAR-2},
author = {Jian-Chao Sun and Jiang He and Shuang-Nan Zhang and Shao-Lin Xiong and Jiang-Tao Liu and Yan-Bing Xu and Jia Ma and Shuo Wang and Lei Shuai and Xiu-Zuo Liang and Hong-Bang Liu and Fei Xie and Ming Zeng and Philipp Azzarello and Joerg Bayer and Franck Cadoux and Nicolas De Angelis and Huan-Bo Feng and Zu-Ke Feng and Min Gao and Ramandeep Gill and Jonathan Granot and Jochen Greiner and Alejandro Guzman and Jin-Xiu Hu and Yue Huang and Johannes Hulsman and Zheng-Huo Jiang and Merlin Kole and Dao-Wu Li and Han-Cheng Li and Tong-Lei Liao and Long Peng and Agnieszka Pollo and Nicolas Produit and Dominik Rybka and Andrea Santangelo and Li-Ming Song and Chris Tenzer and Xiao-Ming Wang and Yuan-Hao Wang and Bo-Bing Wu and Pei-Lian Wu and Xin Wu and Shuo Xiao and Sheng Yang and Lai-Yu Zhang and Lei Zhang and Yong-Jie Zhang},
journal= {arXiv preprint arXiv:2604.19497},
year = {2026}
}
Comments
60 pages, 24 figures, accepted for publication in Exp. Astron