Speaker
Description
In the next generation of experiments in high energy particle physics a large increase in beam interaction density will necessitate upgrades of particle detectors. Examples are the Ring imaging Cherenkov detectors (RICH) in the planned upgrades of the LHCb, Belle II and ALICE 3 experiments. The upgraded RICH detectors will need photo detectors capable of detecting rings of Cherenkov photons at high rates of true and background events as well as large background radiation. Silicon photomultipliers (SiPMs) are an attractive photodetector candidate, with the main remaining technological challenge being the resistance to neutron radiation damage - during the whole experiment run time, the photodetectors are expected to receive accumulated dose of a couple 10$^{13}$ 1-MeV neutron equivalent/cm$^2$. To achieve the targeted radiation tolerance, as well as other RICH detector requirements, dedicated developments and a combination of radiation damage reduction and mitigation techniques, such as cryogenic cooling, are needed. The spadRICH project is developing a CMOS single-photon avalanche diode (SPAD) based photodetector optimized for the application of the planned RICH detectors, with SPADs designed specifically for radiation hardness and cryogenic operation. SPADs designed by the AQUA Lab in 55 nm BCD technology, 110 nm CMOS image sensor technology and 180 nm CMOS technology were characterized at temperatures between room and liquid nitrogen, before and after irradiation with neutrons up to 10$^{12}$ 1-MeV neutron equivalent/cm$^2$. We report on the results of measurements of dark count rates, afterpulsing probability and response of SPADs to low-level light illumination.
