针对水等效材料在医用电子束剂量测量中修正因子的测量和使用问题,通过扫描医用电子束在水中和水等效材料中的百分深度剂量(percentage depth dose, PDD)曲线,计算获得深度缩放因子cpl、注量缩放因子hpl及总修正因子kpl的实验值。结果表明,通过cpl和hpl组合或仅使用kpl均可将水等效材料测量结果转换为水吸收剂量。比较PDD曲线表明,在10~20MeV电子能量下3种水等效材料通过cpl-hpl修正后的R50,较水中测量最大偏差分别为0.19%、0.28%、0.22%;经kpl修正得到的R50,较水中测量最大偏差分别为0.23%、0.29%、0.18%。结论:研究提供了多种材料cpl-hpl、kpl的实验值,可方便用户快速完成电子束水吸收剂量的测量,相比于cpl-hpl,使用kpl更加简单高效。
Abstract
In view of the measurement and application of the correction factor for water equivalent materials in medical electron beam dose measurement, the experimental values of depth scaling factor (cpl), fluence scaling factor (hpl) and total correction factor (kpl) are obtained by scanning the percentage depth dose (PDD) curve of medical electron beam in water and water-equivalent materials. The results show that the measurement results of water equivalent materials can be converted into absorbed dose to water by the combination of cpl and hpl or only using kpl. Comparing the PDD curves shows that the maximum deviation of R50 of three water-equivalent materials after cpl-hpl correction are 0.19%, 0.28% and 0.22% compared with that measured in water at the electron energy of 10~20MeV. The maximum deviation of R50 obtained by kpl correction are 0.23%, 0.29% and 0.18%, respectively. Conclusion: the experimental data of cpl-hpl and kpl are provided, which is convenient for users to quickly measure the absorbed dose to water of electron beam, and it is simpler and more efficient to use kpl than cpl-hpl.
关键词
电离辐射计量 /
吸收剂量 /
电子束 /
缩放因子 /
修正因子 /
水等效材料
Key words
ionizing radiation measurement /
absorbed dose /
electron beam /
scaling factor /
correction factor /
water-equivalent material
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基金
国家重点研发计划(2023YFF0613500);中国计量科学研究院基本业务费(AKYZD2311)
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