Development of an active target for search.

Abstract: The silicon photomultiplier (SiPM) is a recent and established evolution of the avalanche photodiode (APD). This device is particularly appropriate for the use in scintillation light because of its high sensitivity, high quantum efficiency, and insensitivity to magnetic field (up to 4T). Excellent time and energy resolution in addition to small size are crucial for applications at high rate and single photon production. An active target for the MEG experiment based on very thin scintillating fibres readout by SiPM is considered. The tool should provide a very precise measurement of the muon decay vertex, with an improvement on the positron momentum and angular variable resolutions. A particle identification can be performed between positrons and muons. Muon beam rate, the highest on the world, and spot can be measured and continuously monitored. [Copyright &y& Elsevier]