Integration time window for pulse width modulation readout of silicon photomultipliers for 0.5 mm resolution 3-D position sensitive PET scintillation detectors

In our previous works, we had investigated a pulse width modulation (PWM) based multiplexing readout for a detector that is built from dense stacks of LYSO scintillation crystal elements coupled to position sensitive solid state photomultipliers (PS-SSPMs). In our readout system, each of the PS-SSPM position channel signals are integrated for a set time to obtain event energy and position. In this work, we investigated the integration time´s effect on the detector position and energy resolutions. We discovered that the best energy resolution, which is measured at an integration time of 196 ns, is 17.12%, but the energy resolutions measured at 72 ns and 116 ns of integration time show similar values. In terms of crystal count, integration time of 72 ns shows the largest number of crystals that can be seen.