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| The Monte Carlo Modeling and Experimental Verification of the 90Sr/90Y Source and the Extrapolation Chamber |
| TENG Zhong-bin,SONG Ming-zhe,WANG Hong-yu,WEI Ke-xin,LIU Yun-tao |
| National Key Laboratory for Metrology and Calibration Techniques, China Institute of Atomic Energy, Beijing 102413, China |
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Abstract The Monte-Carlo (MC) model of the 90Sr/90Y source used in the BSS2 β-ray secondary standard and the PTW 23392 extrapolation chamber was constructed. The depth-dose curves produced by the 90Sr/90Y source at the calibrated distance were calculated using BEAMnrc and compared with the experimental results. According to the difference between the simulation results and the experimental results, the MC model of the 90Sr/90Y source was revised. In addition, the extrapolation curve of the extrapolation chamber, the tissue transmission factor and the tissue absorbed dose rate at the calibration position were simulated. Under the condition of 30cm away from the source and using the beam flattening filter, the calculated extrapolation curves are in good agreement with the experimental results. The differences between the simulated results of the transmission factor and the absorbed dose rate in tissue and the calibration certificate values are within 1.43%and 2.11%, respectively. The mentioned study constructed a more accurate MC model of the 90Sr/90Y source and extrapolation chamber. The results can provide a reference for the calculation of the β fluence spectrum, dose conversion factor and correction factors of the extrapolation chamber in β reference radiation field.
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Received: 20 July 2020
Published: 14 November 2022
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2022, Vol. 43 
