Semi-physical simulation method for three-dimensional radiation dose field containing strong radioactive source

Abstract

A semi-physical simulation method for a three-dimensional radiation dose field containing a strong radioactive source comprises the steps that geometric modeling and material modeling are conducted on the radioactive source and a surrounding coating structure through an entity construction structure, and the radioactive source is arranged according to the physical characteristics of radionuclide; then reducing the density of an entity structure in the model to obtain global reference distribution of a three-dimensional radiation dose field, and calculating importance parameters according to the global reference distribution; gradually increasing the density of the entity structure, and performing total variance reduction simulation based on the importance parameters to obtain global asymptotic distribution of the three-dimensional radiation dose field; and finally, global approximate distribution of the three-dimensional radiation dose field under the real density condition is calculated by combining the global reference distribution and the global asymptotic distribution, and then importance parameters are set and Monte Carlo calculation is executed to obtain three-dimensional radiation dose field distribution under the real density condition. According to the method, the efficiency of Monte Carlo shielding calculation can be effectively improved, and efficient and accurate semi-physical simulation of a real physical model is realized, so that the safety and controllability of radioactive source processing are improved.

Description

technical field [0001] The invention relates to a technology in the field of radiation protection for radioactive source disposal, in particular to a semi-physical simulation method for a three-dimensional radiation dose field containing a strong radioactive source based on a real physical model and a Monte-Carlo transport simulation. Background technique [0002] When coating a strong radioactive source, it is necessary to know the three-dimensional radiation dose field distribution around the radioactive source, so as to realize the safe and controllable processing of the radioactive source. However, since the detector cannot be placed inside the solid structure, the radiation dose value at that location cannot be obtained by measurement. In this case, the radiation dose rate at that location needs to be obtained through semi-physical simulation technology. The semi-physical simulation technology needs to ensure the high precision and high efficiency of the simulation proc...

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Problems solved by technology

[0003] The present invention aims at the problem that it is impossible to measure the three-dimensional radiation dose field distribution around the radioactive source by placing a detector when the radioactive source is coated in the prior art, and the problem that the traditional method cannot guarantee the accuracy and efficiency at the same time, and proposes a strong The semi-physical simulation method of the three-dimensional radiation dose field of the radioactive source is based on the real physical model and the Monte Carlo transport calculation to simulate the three-dimensional radiation dose field, and the simulation technology of "benchmark + asymptotic + approximation + real" is proposed to effectively improve the Monte Carlo The efficiency of shielding calculations enables efficient and accurate semi-physical simulation of real physical models, thereby improving the safety and controllability of radioactive source processing

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