A shashlik calorimeter readout with silicon photomultipliers with no amplification of the output signal

Silicon PhotoMultipliers are silicon photodetectors that can be used to replace the photomultiplier tubes in many experimental situations. In this article we describe the performance of SiPMs as a readout system of a shashlik calorimeter composed of 70 11.5x11.5 cm2 4 mm thick tiles of scintillator and 69 11.5x11.5 cm2 1.5 mm thick tiles of lead for a total of ~ 19 radiation lengths; the light is collected by 144 1.2 mm wave-length-shifter (WLS) fibers grouped in bundles of nine for a total of 16 channels. The SiPMs are manufactured by FBK-irst and have a sensitive area of 9 mm2. The calorimeter has been tested at CERN using both a low (PS T9 beamline) and high (SPS H4 beamline) energy beam in 2010.