LAUSR

Purpose: This work studies the detective quantum efficiency (DQE) of a‐Se‐based solid state x‐ray detectors for medical imaging applications using ARTEMIS, a Monte Carlo simulation tool for modeling x‐ray photon, electron and charged carrier transport in semiconductors with the presence of applied electric field. Methods: ARTEMIS is used to model the signal formation process in a‐Se. The simulation model includes x‐ray photon and high‐energy electron interactions, and detailed electron‐hole pair transport with applied detector bias taking into account drift, diffusion, Coulomb interactions, recombination and trapping. For experimental validation, the DQE performance of prototype a‐Se detectors is measured following IEC Testing Standard 62220‐1‐3. Results: Comparison of simulated and experimental DQE results show reasonable agreement for RQA beam qualities. Experimental validation demonstrated within 5% percentage difference between simulation and experimental DQE results for spatial frequency above 0.25 cycles/mm using uniform applied electric field for RQA beam qualities (RQA5, RQA7 and RQA9). Results include two different prototype detectors with thicknesses of 240 μm and 1 mm. Conclusions: ARTEMIS can be used to model the DQE of a‐Se detectors as a function of x‐ray energy, detector thickness, and spatial frequency. The ARTEMIS model can be used to improve understanding of the physics of x‐ray interactions in a‐Se and in optimization studies for the development of novel medical imaging applications.