High Resolution gamma ray detector array using Geiger mode avalanche photodiode array (silicon photomultiplier)
Institution: Washington University in St. Louis
This invention describes a new gamma ray detector array made of (1) an array of scintillator crystals, (2) a light guide for light diffusion and direction, (3) an array of single-element silicon photomultiplier device (or its equivalent), or a multiple-element silicon photomultiplier device (or its equivalent), (4) light reflector for re-direction of light photons, (5) charge-division resistor network, and (6) charge sensitive amplifiers. The main features that are new in this invention include (1) the use of light reflector between the light guide and the array of silicon photomultiplier to re-direct light photons toward the sensitive area of the silicon photomultiplier; (2) direct coupling of the silicon photomultiplier’s output to the charge division resistor network for signal multiplexing in order to minimize the number of charge-sensitive amplifier required for a detector array and to eliminate the noise from the amplifiers being included in the multiplexing of signals.
Edward R. Fickenscher