Construction of voxel-based Portunus haanii phantom and its absorbed fractions and specific absorbed fractions calculation based on Monte Carlo simulations

Objective:To build the database of the absorbed fractions(AFs)and specific absorbed fractions(SAFs),in order to accurately assess the internal radiation dose in non-human biota. Methods:A voxel-based Portunus haanii phantom was established based on the computed tomography(CT)images.A set of AFs and SAFs were calculated with Monte Carlo toolkit Geant4 for the emission of monoenergetic photons and electrons with energies ranging from 10 keV to 5 MeV. Results:The mass of the voxel-based Portunus haanii phantom(392.2 g)was in agreement with the actual mass(389.2 g),indicating the reliability of the phantom.The calculated AFs and SAFs,based on the voxel-based Portunus haanii phantom,provided precise and reliable data for conducting internal radiation dose calculations specifically tailored to the Chinese Red Swimming Crab(Portunus haanii).The results indicated that the self-AFs and self-SAFs were affected by both the radiation energy and the mass of the source/target organ.Moreover,the AFs and SAFs for cross irradiation,were not only dependent on the energy and the mass of the target organ,but also on the relative position of the source and target organs. Conclusion:These results serve as a valuable resource for accurately evaluating the internal radiation exposure of this species.