Experimental validation of the ANTS2 code for modelling optical photon transport in monolithic LYSO crystals

Characterization of intrinsic radiation in LYSO scintillators using GEANT4 and SimSiPM simulations

The intrinsic radiation spectra of LYSO scintillators are investigated through detailed GEANT4 and SimSiPM simulations, focusing on how changes in configuration and size influence the radiation characteristics. Using these simulation packages together, a comprehensive simulation of the physical processes as well as a detailed simulation of the photodetector response, including factors such as dark count rate, optical crosstalk, afterpulse, noise, and saturation effects, was performed. The results of the simulations indicate that the primary factor affecting the intrinsic radiation pattern is the total volume of the crystal, rather than surface treatments or minor geometric variations. The consistency between GEANT4 and SimSiPM simulations confirms the validity of using these simulation methods to analyze the spectral behavior of LYSO scintillators detailed in various applications such as positron emission tomography and nuclear spectroscopy.

Discrete Convolution-Based Energy Spectrum Configuring Method for the Analysis of the Intrinsic Radiation of 176Lu

There has been considerable interest in inorganic scintillators based on lutetium due to their favorable physical properties. Despite their advantages, lutetium-based scintillators could face issues because of the natural occurring radioisotope of ¹⁷⁶Lu that is contained in natural lutetium. In order to mitigate its potential shortcomings, previous works have studied to understand the energy spectrum of the intrinsic radiation of ¹⁷⁶Lu (IRL). However, few studies have focused on the various principal types of photon interactions with matter; in other words, only the full-energy peak according to the photoelectric effect or internal conversion have been considered for understanding the energy spectrum of IRL. Thus, the approach we have used in this study considers other principal types of photon interactions by convoluting each energy spectrum with combinations for generating the spectrum of the intrinsic radiation of ¹⁷⁶Lu. From the results, we confirm that the method provides good agreement with the experiment. A significant contribution of this study is the provision of a new approach to process energy spectra induced by mutually independent radiation interactions as a single spectrum.