Ground calibration of Gamma-Ray Detectors of GECAM-C

As a new member of the GECAM mission, GECAM-C (also named High Energy Burst Searcher, HEBS), launched onboard the SATech-01 satellite on July 27th, 2022, is capable of monitoring gamma-ray transients from similar to 6 keV to similar to 6 MeV. GECAM-C is equipped with 12 gamma-ray detectors (GRDs) as its main detectors. To test the performance of GECAM-C GRDs and verify the energy response simulated by Monte Carlo, comprehensive on-ground calibration experiments have been performed using X-ray beam and radioactive sources, including Channel-Energy relation, energy resolution, detection efficiency, Silicon Photomultipliers (SiPM) voltage-gain relation, and non-uniformity of positional response. This paper presents the calibration campaigns and the results of data analysis for GECAM-C GRDs.