Development of a novel compact and fast SiPM-based RICH detector for the future ALICE 3 PID system at LHC

TL;DR

This paper presents the development and testing of a compact, fast SiPM-based RICH detector prototype for the ALICE 3 experiment at LHC, featuring integrated Cherenkov timing measurements and novel radiator configurations.

Contribution

It introduces a new SiPM-based RICH detector prototype with integrated timing capabilities and demonstrates its successful testing at CERN, advancing particle identification technology.

Findings

Successful beam tests with pions and protons at CERN

Effective integration of Cherenkov timing measurements

Prototype demonstrates promising performance for future ALICE 3 detector

Abstract

A dedicated R\&D is ongoing for the charged particle identification system of the \mbox{ALICE 3} experiment proposed for the LHC Run 5 and beyond. One of the subsystems for the high-energy charged particle identification will be a Ring-Imaging Cherenkov (RICH) detector. The possibility of integrating Cherenkov-based charged particle timing measurements is currently under study. The proposed system is based on a proximity-focusing RICH configuration including an aerogel radiator separated from a SiPM array layer by an expansion gap. A thin high-refractive index window of transparent material, acting as a second Cherenkov radiator, is glued on the SiPM array to enable time-of-flight measurements of charged particles by exploiting the yield of Cherenkov photons in the thin window. We assembled a small-scale prototype instrumented with different Hamamatsu SiPM array sensors with pitches ranging from 1 to 3 mm, readout by custom boards equipped with the front-end Petiroc 2A ASICs to measure charges and times. The primary Cherenkov radiator consisted of a 2 cm thick aerogel tile, while various window materials, including SiO$_2$ and MgF$_2$, were used as secondary Cherenkov radiators. The prototype was successfully tested in a campaign at the CERN PS T10 beam line with pions and protons. This paper summarizes the results achieved in the 2023 test beam campaign.