Optimal Optical Conditions and Positioning Scheme for an Ultrahigh-Resolution Silicon Drift Detector-Based Gamma Camera

In this study, we optimized the optical conditions and associated positioning scheme for an ultrahighspatial-resolution, solid-state gamma detector. The detector module consisted of an array of seven hexagonal silicon drift detectors (SDDs) packed hexagonally and coupled to a single slab of crystal via a light guide glass. Because the optical behavior and requirements of the detector module and noise characteristics of the SDD sensor are different from those of conventional photomultiplier tube (PMT)-based detectors, the following parameters were studied to determine the optimum condition: scintillator selection, the effect of cooling on signal-to-noise ratio (SNR), the depth dependence of the scintillation light distribution, and optimum shaping time. To that end, a modified, Anger-style positioning algorithm with a denoise scheme was also developed to address the estimation bias (pincushion distortion) caused by the excessively confined light distribution and the leakage current induced by the SDD senso...