The Timing Counter of the MEG experiment: Design and commissioning

The Timing Counter of the MEG experiment is designed to deliver trigger information and to accurately measure the time of flight of the e + for searching the decay μ + → e + γ. It consists of two sectors upstream and downstream the decay target. Each sector is made of two layers: scintillating fibers read by APD for trigger and track reconstruction in the inner side, scintillating bars with PMT readout for trigger and time measurement in the outer one. The design criteria and commissioning of the detector are presented.