Speaker
Description
A 256-pixel Silicon Photomultiplier (SiPM) camera developed for a 4-m diameter atmospheric Cherenkov telescope was commissioned in October 2024. The telescope is located at Mt. Abu, Rajasthan, India, and is part of the TACTIC array established by BARC. A dedicated nanosecond light-flasher system was implemented to enable precise and periodic calibration of the camera photosensors and the complete readout chain. The flasher, capable of delivering up to 1000 photoelectrons per pixel, was used to calibrate the photosensors under very low light conditions, allowing measurements of absolute gain, linearity, timing response, and pixel-to-pixel uniformity. Calibration results obtained from laboratory test-bench studies and in-situ telescope operation are presented.