Silicon Photomultiplier Performance Study and Preamplifier Design for the Wide Field of View Cherenkov Telescope Array of LHAASO

摘要

The Wide Field of View Cherenkov Telescope Array (WFCTA), a main component of the LHAASO, requires a dynamic range between 10 and 32000 photoelectrons (pes) and stable gain of the photosensors. Silicon photomultipliers (SiPMs) are relatively new kind devices with respect to photomultipliers (PMT). Their performance are improving very rapidly since 1990s. SiPMs suffer for negligible ageing even under strong light exposure. SiPM-based cameras could operate under high moon conditions and their duty-cycle is larger than that of PMT-based camera. The design of preamplifier for the WFCTA camera is described this paper. Moreover properties of the SiPMs are studied, such as their linearity at high number of photoelectrons. An analytical function is derived to relate number of fired cells and the total number of cells in the SiPM. We also compare the performance of SiPMs and PMTs under long light pulses up to 3 μs. Furthermore, the additional non-linearity due to disuniformities in light distribution is also evaluated.