National Key Laboratory for Metrology and Calibration Techniques, China Institute of Atomic Energy, Beijing 102413, China.
National Institute of Metrology, Beijing 100029, China.
Radiat Prot Dosimetry. 2023 May 3;199(7):615-622. doi: 10.1093/rpd/ncad058.
For the purpose of obtaining the smaller uncertainties for Hp(3) and Dp lens in 90Sr/90Y beta reference fields, a new dose determination method based on the Monte-Carlo simulation was proposed. The conversion coefficients from the absorbed dose in air, at the reference point of the extrapolation ionisation chamber, Dair, det to Hp(3; α) and the conversion factors from Dair, det to Dp lens(α) were calculated with EGSnrc, respectively, for the irradiation angles from 0° to 60°. Compared with the dose determination method in International Organization for Standardization (ISO) 6980 standard, the uncertainty reductions of 7.7-52.8% for Hp(3; α) and 7.9-55.0% for Dp lens(α) were achieved, respectively. In addition, for the conversion coefficients from the reference absorbed dose DR to Hp(3; α), the calculations were performed for more irradiation conditions, which are not included in the current ISO 6980 standard. For the calculations of the conversion factors from DR to Dp lens(α), the eye and head phantoms with Chinese characteristics were utilised, which makes the conversion factors more suitable for use in China.
为了在 90Sr/90Yβ参考场中获得更小的 Hp(3)和 Dp 剂量不确定性，提出了一种基于蒙特卡罗模拟的新剂量确定方法。利用 EGSnrc 分别计算了从 0°到 60°辐照角度的空气中吸收剂量在参考电离室探测点的转换系数 Dair,det 到 Hp(3;α)以及从 Dair,det 到 Dp 透镜(α)的转换因子。与国际标准化组织（ISO）6980 标准中的剂量确定方法相比，Hp(3;α)的不确定度分别降低了 7.7%-52.8%，Dp 透镜(α)的不确定度分别降低了 7.9%-55.0%。此外，对于从参考吸收剂量 DR 到 Hp(3;α)的转换系数的计算，还针对当前 ISO 6980 标准中未包含的更多辐照条件进行了计算。对于从 DR 到 Dp 透镜(α)的转换因子的计算，使用了具有中国特色的眼和头部体模，这使得转换因子更适合在中国使用。
