Compact readout electronics for position sensitive photomultiplier tubes

Two charge multiplexed readout schemes for Position Sensitive Photomultiplier Tubes (PSPMTs) have been developed and evaluated. A two-stage split-charge method is compared to standard positional charge division. The resulting electronic circuits are highly compact and will be initially incorporated into a small hand-held nuclear gamma ray imager for cancer staging. Electrical tests on the readout electronics are performed and intrinsic scintillation camera performance is evaluated using a 23×23 array of pixilated 2×2×3 mm³ LSO crystals coupled to a H8500 flat-panel PSPMT.