Single Side Readout Depth of Interaction Method With Wavelength Discrimination

Depth of interaction (DOI) information is important in the development of high-resolution detectors as it helps to reduce parallax error in positron emission tomography (PET) systems. Further, the determination of depth in the crystal is important for making scintillation crystal-based detectors in many other applications, such as the Compton imager and multi-radiation imagers. In this paper, a novel DOI method based on discrimination of the wavelength of the scintillation light emitted from a single side readout system is proposed. The single side readout facilitates flexibility in the final system in a geometrical configuration. The proposed method can be applied to stacked detectors with emissions of various wavelengths in crystals (e.g., LYSO and GAGG) and long monolithic detectors utilizing the wavelength dependence of internal light absorption. Simulations performed of the proposed discrimination principle via Monte Carlo simulation based on SLITRANI and experiments conducted using two silicon photomultipliers (SiPMs) with wavelength filters verify the feasibility of the proposed method.