He jishu (Oct 2021)
Simulation study on the fraction of environmental scattered radiation in mobile X-ray reference radiation field
Abstract
BackgroundFixed X-ray and γ-ray radiation dosimeters are important tools for evaluating the operational status of equipment and personnel safety. On-site calibration method of this type of instrument has gradually become a research hotspot. A mobile X-ray irradiation device is developed by the Division of Radiation Metrology of China Institute of Atomic Energy for field calibration.PurposeThis study aims to build the computational model of this mobile X-ray irradiation device for simulation, and to carry out experimental verification of environmental scattered radiation for on-site calibration of these dosimeters.MethodsFirstly, a simplified model of the irradiation device and environment with the same scale was established by Monte Carlo N Particle Transport Code (MCNP) to determine calculation method of the environmental scattered radiation. Secondly, the model verification work was carried out under the basic scenario conditions were analyzed, and the model size was adjusted by analysis of the main factors affecting the results. Finally, the improved model was verified by experiments.ResultsThe half opening angles of aperture model are finally determined to be 5°, 8°30′ and 10°20′. The relative deviation between the calculated results of the improved model and the experimental results were -11.6% ~ 9.3% in the radiation quality index range of N100~N200.ConclusionsA significant amount of experimental measurement time can be saved by this computational model, and it is feasible to use the validated model to provide training data for the development of a machine learning-based in-situ X-ray scattering radiation correction system.
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