Performance of a 3 mm×3 mm silicon photomultiplier for use on the X-ray calibration system of the SVOM gamma ray monitor

The calibration detector of a gamma ray monitor (GRM) is designed to detect alpha particles from Am-241 and to send out the coincidence signal to the GRM X-ray detector. The silicon photomultiplier (SiPM), as a novel photon device, is a good candidate to convert alpha-exciting fluorescent photons into electric signals. Three types of SiPMs from SSPM and MPPC, each having an active area of 3 mm x 3 mm, were compared in the matter of the spectra from low-intensity light, dark count, crosstalk probability and I-V curve. The temperature coefficient of SSPM-0710G9MM was also characterized. The application of a SiPM on the GRM has been proved to be feasible.