Development of a sub-100 ps Time-of-Flight detector with SiPM-readout scintillator for measurement of cosmic muon velocity

TL;DR

This paper presents a high-precision cosmic muon TOF detector using SiPM-readout scintillators, achieving sub-100 ps resolution with a novel multi-face readout topology, suitable for future particle identification upgrades.

Contribution

The study introduces a multi-face 4S SiPM readout topology that significantly improves timing resolution for large scintillators in TOF measurements.

Findings

Achieved approximately 68 ps coincidence time resolution with the multi-face 4S topology.

Demonstrated successful measurement of cosmic muon velocity using the developed detector.

Outperformed traditional hybrid topologies in timing performance.

Abstract

Accurate Time-of-Flight (TOF) measurement with sub-100 picosecond resolution is a critical requirement for particle identification in future high-energy physics experiments, such as the Belle II $K_{L}$ and Muon (KLM) detector upgrade. Achieving this precision with large-area Silicon Photomultipliers (SiPMs) is challenging due to the inherent junction capacitance, which degrades signal rise time. In this work, we developed and evaluated a high-time-resolution cosmic ray detector based on plastic scintillators and customized SiPM arrays. To optimize the readout for block-shaped scintillators, we systematically compared different sensor topologies. We demonstrate that a multi-face readout topology, utilizing low-capacitance 4-series (4S) SiPM modules coupled to four faces of the scintillator, achieves an excellent coincidence time resolution of approximately 68 ps, outperforming the $\sim$100 ps resolution of the concentrated 4-series 3-parallel (4S3P) hybrid topology. Furthermore, to validate the system's practical performance, we successfully measured well-known cosmic ray observables, specifically the relativistic muon velocity via TOF reconstruction. These results highlight the potential of the multi-face 4S configuration as a high-precision solution for future TOF detector upgrades.