Pitch Angle Measurement Method based on Detector Counts Distribution. -I. Basic conception
Abstract
As an X-ray and gamma-ray all-sky monitor aiming for high energy astrophysical transients, Gravitational-wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) has also made a series of observational discoveries on burst events of gamma-rays and particles in the low Earth orbit. Pitch angle is one of the key parameters of charged particles traveling around geomagnetic field. However, the usage of the GECAM-style instruments to measure the pitch angle of charged particles is still lacking. Here we propose a novel method for GECAM and similar instruments to measure the pitch angle of charged particles based on detector counts distribution. The basic conception of this method and simulation studies are described. With this method, the pitch angle of a peculiar electron precipitation event detected by GECAM-C is derived to be about 90, demonstrating the feasibility of our method. We note that the application of this method on GECAM-style instruments may open a new window for studying space particle events, such as Terrestrial Electron Beams (TEBs) and Lightning-induced Electron Precipitations (LEPs).
Cite
@article{arxiv.2505.06167,
title = {Pitch Angle Measurement Method based on Detector Counts Distribution. -I. Basic conception},
author = {Chenwei Wang and Shaolin Xiong and Hongbo Xue and Yiteng Zhang and Shanzhi Ye and Wei Xu and Jinpeng Zhang and Zhenghua An and Ce Cai and Peiyi Feng and Ke Gong and Haoxuan Guo and Yue Huang and Xinqiao Li and Jiacong Liu and Xiaojing Liu and Xiang Ma and Liming Song and Wenjun Tan and Jin Wang and Ping Wang and Yue Wang and Xiangyang Wen and Shuo Xiao and Shenlun Xie and Yanbing Xu and Wangchen Xue and Sheng Yang and Zhenghang Yu and Dali Zhang and Wenlong Zhang and Peng Zhang and Shuangnan Zhang and Yanqiu Zhang and Yanting Zhang and Zhen Zhang and Xiaoyun Zhao and Chao Zheng and Shijie Zheng},
journal= {arXiv preprint arXiv:2505.06167},
year = {2025}
}