x-y position read-out of a YAP:Ce crystal matrix using wavelength shifting fibers

A set of preliminary test results of a detector prototype for PET applications is presented. The detector is made of a YAP:Ce finger crystal (2×2×30 mm³ each) matrix coupled to a set of square section wave length shifting fibers (one fiber for each matrix row and one fiber for each matrix column) read by a position sensitive detector. The recognition of each fiber allows the determination of x-y position of the scintillation event. The light yield of the system has been investigated: all possible light loss factors have been taken into account to evaluate the expected signal. Experimental measurements with a single pixel HPD have been performed. We have measured about 10 photo-electrons for a deposit of 511 keV in the scintillator for each coordinate. Preliminary position measurement with a small 5×5 matrix are presented