A POSITRON CAMERA DETECTOR DESIGN WITH CROSS-COUPLED SCINTILLATORS AND QUADRANT SHARING PHOTOMULTIPLIERS

A new positron camera scintillation detector design is proposed. This design uses discrete scintillators tightly optically coupled (glued) together to form a block. The coupling interfaces between crystals have different degree of polish depending of the interface location within the block. Each block has the same dimension as that of the photomultipliers (PMT) used, but the blocks and the PMT array are off-set in both X-Y directions. Advantages of the design are: (a) higher detection efficiency with almost 100% packing fraction, (b) very uniform signal pulse-heights even for very small crystals at the edge of the block, (c) the decoding is less dependent of the depth of interaction (d) significantly decreasing the number of PMT by up to 75 %, and (e) with the smallest PMT (1.0 cm) currently available, spatial resolution in the range of 1-2mm may potentially be achieved.