(90)^Sr/(90)^Y放射源及外推电离室蒙特卡罗模型建立与实验验证  

The Monte Carlo Modeling and Experimental Verification of the(90)^Sr/(90)^Y Source and the Extrapolation Chamber

作　　者：滕忠斌 宋明哲[1] 王红玉[1] 魏可新[1] 刘蕴韬[1] 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)

机构地区：[1]中国原子能科学研究院计量与校准技术国防科技重点实验室,北京102413

出　　处：《计量学报》2022年第11期1512-1517,共6页Acta Metrologica Sinica

摘　　要：针对β射线次级标准装置(BSS2)中的(90)^Sr/(90)^Y放射源以及PTW23392型外推电离室进行蒙特卡罗(MC)建模。使用BEAMnrc计算(90)^Sr/(90)^Y放射源在不同校准位置处产生的组织深度剂量曲线,并与实验结果进行比较。根据模拟结果与实验结果的差异,修正放射源MC模型。此外,对外推电离室的外推曲线、校准位置处的组织透射因子和组织吸收剂量率进行模拟计算。在距离放射源30 cm和使用展平过滤的条件下,外推曲线的计算结果和实验结果基本吻合。组织透射因子和组织吸收剂量率的模拟结果与校准证书值相差分别在1.43%和2.11%之内。最终建立了较为准确的(90)^Sr/(90)^Y放射源和外推电离室的MC模型,研究结果可以为计算β参考辐射场中的注量谱、剂量转换系数和外推电离室相关的修正因子等提供参考。The Monte-Carlo(MC)model of the(90)^Sr/(90)^Y source used in the BSS2β-ray secondary standard and the PTW 23392 extrapolation chamber was constructed.The depth-dose curves produced by the(90)^Sr/(90)^Y 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(90)^Sr/(90)^Y 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 30 cm 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(90)^Sr/(90)^Y source and extrapolation chamber.The results can provide a reference for the calculation of theβfluence spectrum,dose conversion factor and correction factors of the extrapolation chamber inβreference radiation field.

关 键 词：计量学 β参考辐射 外推电离室 深度剂量曲线 组织吸收剂量率 蒙特卡罗建模 

分 类 号：TB98[一般工业技术—计量学]