Development and commissioning of the Timing Counter for the MEG Experiment

TL;DR

The paper describes the design, performance, and commissioning of the Timing Counter for the MEG experiment, which measures positron timing to search for rare muon decays with high precision.

Contribution

It introduces a novel Timing Counter with layered scintillating fibers and bars, optimized for trigger and timing in the MEG experiment.

Findings

Successful detector commissioning and performance validation

High timing resolution achieved for positron detection

Effective integration within the MEG spectrometer

Abstract

The Timing Counter of the MEG (Mu to Electron Gamma) experiment is designed to deliver trigger information and to accurately measure the timing of the $e^+$ in searching for the decay $\mu^+ \rightarrow e^+\gamma$. It is part of a magnetic spectrometer with the $\mu^+$ decay target in the center. It consists of two sectors upstream and downstream the target, each one with two layers: the inner one made with scintillating fibers read out by APDs for trigger and track reconstruction, the outer one consisting in scintillating bars read out by PMTs for trigger and time measurement. The design criteria, the obtained performances and the commissioning of the detector are presented herein.