Long-term operation of a multi-channel cosmic muon system based on scintillation counters with MRS APD light readout

TL;DR

This paper reports on the long-term successful operation of a large-scale cosmic muon detection system using innovative scintillation counters with MRS APD light readout, demonstrating high efficiency and stability over extensive operation hours.

Contribution

It introduces a large-scale CRTF system based on START technology with MRS APD readout, showcasing its durability and performance in cosmic muon detection.

Findings

100% muon detection efficiency achieved

Less than 10^{-2} Hz noise level in detection

Over 25,000 hours of stable operation

Abstract

A Cosmic Ray Test Facility (CRTF) is the first large-scale implementation of a scintillation triggering system based on a new scintillation technique known as START. In START, the scintillation light is collected and transported by WLS optical fibers, while light detection is performed by pairs of avalanche photodiodes with the Metal-Resistor-Semiconductor structure operated in the Geiger mode (MRS APD). START delivers 100% efficiency of cosmic muon detection, while its intrinsic noise level is less than 10^{-2} Hz. CRTF, consisting of 160 START channels, has been continuously operated by the ALICE TOF collaboration for more than 25 000 hours, and has demonstrated a high level of stability. Fewer than 10% of MRS APDs had to be replaced during this period.