Scintillation detection using 3 mm × 3 mm silicon photomultipliers

A silicon photomultiplier (SiPM) consists of an array of independent Geiger-mode avalanche photodiodes, each with an integrated quenching resistor. SiPMs have many potential attractive features, including high photon detection efficiency, high gain, low timing jitter, compact design, and low operating voltage. We are evaluating SiPMs for use in scintillation detectors, and present results using 3 mm x 3 mm Multi-Pixel Photon Counter (MPPC^TM)prototypes from Hamamatsu Photonics K. K. coupled to LYSO scintillator crystals. Our evaluation includes energy resolution, timing resolution, and the sensitivities of these measurements to bias voltage and temperature variations. We have also used simulations to try to understand the impact of avalanche photodiode reset time and cross-talk on the observed non- linearity of the pulse-height spectrum.