Speaker
Description
The dual-radiator Ring Imaging Cherenkov detector (dRICH) of the ePIC experiment at the future Electron–Ion Collider will provide charged-hadron particle identification in the hadron-going region over a broad momentum range. Cherenkov photons will be detected by a large-area, position-sensitive silicon photomultiplier photodetector plane covering about 3 m², with 3 × 3 mm² pixels and more than 300,000 readout channels. This represents the first large-scale application of SiPMs for single-photon detection in a high-energy physics RICH detector.
We report on the development and beam-test validation of a real-scale dRICH prototype corresponding to one sector of the full detector. The prototype instruments an active photodetection area of about 15 × 15 cm², corresponding to more than 2,000 channels, while preserving the final detector granularity and the relevant optical layout, including the dual aerogel–gas radiator configuration and the off-axis focusing geometry. The photodetector is based on compact photodetection units, each integrating 256 SiPM pixels, local cooling, and fast front-end TDC electronics. The system is read out through a complete chain based on the ALCOR ASIC, allowing validation under realistic operating conditions.
A dedicated CERN beam-test campaign in 2026, at the SPS and PS, is being used to assess the detector response under complementary beam conditions. Key observables include the number of detected photoelectrons, single-photon Cherenkov-angle resolution, timing performance, and stability of the readout chain. These measurements provide essential input for the optimisation of the final ePIC dRICH photodetector system and demonstrate the potential of granular SiPM-based imaging sensors for future high-rate particle-identification detectors.