Time characteristics of silicon photomultipliers used in the GlueX experiment

The GlueX detector in Hall D at Jefferson Lab is instrumented with about 5000 Silicon Photomultipliers (SiPM) manufactured by Hamamatsu Corporation. Silicon photomultipliers with a sensitive area of 3×3 mm 2 are used to detect light from scintillator detectors such as: the tagger microscope, pair spectrometer, and start counter. An array of 4×4 SiPM sensors was specially designed by Hamamatsu for the instrumentation of the barrel electromagnetic calorimeter. SiPMs in the tagger microscope and start counter will be operated at a relatively large rate of up to 2 MHz. We performed measurements of the time resolution for different SiPM operation rates and estimated the SiPM recovery time. Time characteristics were compared for sensors with two pixel sizes: 25 μm (MPPC S10362-33-025C, MPPC S10931-025P) and 50 μm (MPPC S10362-33-050C, MPPC S10931-050P). Time resolution of the SiPM array (MPPC S12045) was measured as a function of light for several SiPM temperatures. Studies were performed using a picoseconds laser light pulser and a light-emitting diode.