Design of front-end electronic circuits for dedicated PET detectors

The new high spatial resolution PET detectors for small animal and breast imaging have been designed. Position-sensitive photo-multipliers (R7600-C12) and dual-layer pixelated BGO crystals are employed to detect and localize gamma rays. A modified high-voltage divider with last dynode readout circuits, a front-end positioning readout circuits, and a last dynode timing amplifier have been investigated and developed for these detectors. Methods for combining four PS-PMTs with simple X-, X+, Y-, and Y+ outputs have been developed to further simplify the positioning processing. The front-end circuits are small so they can be fit in the detector's structure. A prototype of two detector modules, each having two PS-PMTs with corresponding electronic circuits, has been built for evaluation.