A combined SiPM-based TOF+RICH detector for future high-energy physics experiments

A novel compact particle identification (PID) detector concept based on Silicon Photomultipliers (SiPMs) optimized to perform combined Time-of-Flight (TOF) and Ring-Imaging Cherenkov (RICH) measurements using a common photosensitive sensor is under development. The system consists of a Cherenkov radiator layer separated from a photosensitive surface equipped with SiPMs by an expansion gap. A thin glass slab, acting as a second Cherenkov radiator, is coupled to the SiPMs to perform Cherenkov-based TOF measurements. We have built and tested a detector prototype including a 2 cm thick aerogel radiator and a 3 mm thick NaF slab. With a RICH resolution better than 1 mrad and a TOF resolution better than 50 ps, the present technology makes the proposed SiPM-based PID system particularly attractive for future high-energy physics experiments where space and cost constraints are critical. In this work, we discuss the principle of operation of the proposed TOF+RICH integration, with a particular focus on the optimization of the TOF radiator material, thickness and coupling with SiPMs, as well as the achievable angular and timing performance. Finally, preliminary beam test results for the considered detector prototype are presented.