A
scintillation block
detector employs an array of optically
air coupled scintillation pixels, the array being wrapped in reflector material and optically coupled to an array of
silicon photomultiplier light sensors with common-
cathode signal timing pickoff and individual
anode signal position and energy determination. The design features afford an optimized combination of photopeak energy event sensitivity and timing, while reducing
electronic circuit complexity and power requirements, and easing necessary fabrication methods. Four of these small blocks, or “miniblocks,” can be combined as optically and electrically separated quadrants of a larger single
detector in order to recover detection efficiency that would otherwise be lost due to scattering between them. Events are validated for
total energy by summing the contributions from the
four quadrants, while the trigger is generated from either the timing
signal of the quadrant with the highest energy deposition, the first timing signal derived from the four quadrant time-pickoff signals, or a statistically optimum combination of the individual quadrant event times, so as to maintain good timing for scatter events. This further reduces the number of electronic channels required per unit
detector area while avoiding the timing degradation characteristic of excessively large SiPM arrays.