The technology for detection of gamma-ray burst with GECAM satellite

Introduction The main physical objective of the GECAM satellite is to detect gamma-ray bursts, which is related to gravitational waves of double compact object mergers. The GECAM satellite also detects and investigates various bursts of high-energy celestial bodies. Purposes and methods In this study, we designed, developed and calibrated the payload and launched it into orbit with GECAM satellite. The payload consists of the gamma ray detector (GRD, for detecting 4 keV–4 MeV X/γ ray), the charged particle detector (CPD, for detecting 150 keV–5 MeV charged particle), and the electronic box (EBOX). The all-sky field coverage is achieved via two 229-degree large-area satellites positioned 180 degrees apart and are on opposite sides of the geo-center. Each satellite is equipped with 25 GRDs and 8 CPDs; thus, the satellite can identify charged particle bursts in space. Gamma-ray detectors adopt lanthanum bromide crystal technology combined with silicon photomultipliers. This is the first time that this technology was used massively in space detectors. Conclusions The GECAM satellite can quickly determine the direction of gamma-ray bursts (positioning) via indexing and fitting method, while the transmit variability, energy spectrum and direction of the gamma-ray bursts guide subsequent observations through the Beidou-3 RDSS in quasi-real time. It will play an important role in the study of high energy celestial bursts.