Characterizing the spatial resolution performance of continuous & thick LYSO crystals

Our goal is to develop a thick continuous detector with high spatial resolution. We will use simulations with experimental measurements to examine performance of two crystal blocks: a 46×46×14mm³ and a 48×48×25mm³ block of LYSO. Based upon the light distribution pattern in the 46×46×14mm³ crystal, we can measure spatial resolution of 3mm in the central region of the crystal with degradation near the edges due to reflections off the crystal sides. We show that we can match the spatial resolution obtained with Maximum Likelihood (ML) positioning of the 14mm thick crystal with that of the 25mm thick crystal using slots cut into the gamma entrance surface of the crystal. Also by modifying the reflectivity of the crystal sides we can improve the spatial resolution performance near the edges with some loss in energy resolution.