ISO 4037-2:2019 放射防护 标定剂量计和剂量计并确定其作为光子能量函数的响应的X和伽玛参考辐射 第2部分：能量范围从8kev到1,3 MeV和4 MeV到9 MeV的辐射防护剂量学

标准编号：ISO 4037-2:2019

中文名称：放射防护 标定剂量计和剂量计并确定其作为光子能量函数的响应的X和伽玛参考辐射 第2部分：能量范围从8kev到1,3 MeV和4 MeV到9 MeV的辐射防护剂量学

英文名称：Radiological protection — X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy — Part 2: Dosimetry for radia

发布日期：2019-01

标准范围

本文件规定了用于校准能量范围约为8 keV至1,3 MeV和4 MeV至9 MeV的辐射防护仪器的X和伽马参考辐射剂量测定程序，以及空气比释动能率高于1μGy/h的程序。考虑的测量量为空气中的空气比释动能，Ka，以及国际辐射单位和测量委员会（ICRU）[2]、H*（10）、Hp（10）、H'（3）、Hp（3）、H'（0,07）和Hp（0,07）的与模型相关的操作量，以及各自的剂量率。ISO 4037-1中给出了生产方法。本文件也可用于ISO 4037-1:2019附件A、B和C中规定的辐射质量，但这并不意味着这些附件中所述辐射质量的校准证书符合ISO 4037的要求。本文件中给出的要求和方法针对的是参考场中与模型相关的操作量的总剂量（率）不确定度（k=2）约为6%至10%。为了实现这一点，ISO 4037-1中提出了两种参考字段的生成方法。第一种方法是生成“匹配的参考字段”，这些字段非常符合要求，因此可以使用推荐的转换系数。与标称参考场相比，“匹配参考场”的光谱分布仅存在微小差异，通过本文件中给出和详细描述的程序进行验证。对于匹配的参考辐射场，ISO 4037-3中给出的建议转换系数仅适用于源和剂量仪之间的指定距离，例如1,0 m和2,5 m。对于其他距离，用户必须决定是否可以使用这些转换系数。第二种方法是产生“特征化参考场”。要么通过光谱法确定转换系数，要么直接使用二级标准剂量计测量所需值。本方法适用于任何辐射质量、任何测量量以及任何模型和辐射入射角（如适用）。只要空气比释动能不低于1μGy/h，就可以确定任何距离的转换系数。这两种方法都需要参考场的带电粒子平衡。然而，这并不总是在需要校准剂量计的工作场所建立的。在参考深度d没有固有带电粒子平衡的光子能量下尤其如此，这取决于能量和参考深度d的实际组合。能量超过65千电子伏、0.75兆电子伏和2.1兆电子伏的电子只能分别穿透0.07毫米、3毫米和10毫米的ICRU组织，光子能量高于这些值的辐射质量被认为是没有内在带电粒子平衡的辐射质量，在这些深度定义的量。本文件不适用于脉冲参考场的剂量测定。

This document specifies the procedures for the dosimetry of X and gamma reference radiation for the calibration of radiation protection instruments over the energy range from approximately 8 keV to 1,3 MeV and from 4 MeV to 9 MeV and for air kerma rates above 1 μGy/h. The considered measuring quantities are the air kerma free-in-air, Ka, and the phantom related operational quantities of the International Commission on Radiation Units and Measurements (ICRU)[2], H*(10), Hp(10), H'(3), Hp(3), H'(0,07) and Hp(0,07), together with the respective dose rates. The methods of production are given in ISO 4037-1.This document can also be used for the radiation qualities specified in ISO 4037-1:2019, Annexes A, B and C, but this does not mean that a calibration certificate for radiation qualities described in these annexes is in conformity with the requirements of ISO 4037.The requirements and methods given in this document are targeted at an overall uncertainty (k = 2) of the dose(rate) of about 6 % to 10 % for the phantom related operational quantities in the reference fields. To achieve this, two production methods of the reference fields are proposed in ISO 4037-1.The first is to produce "matched reference fields", which follow the requirements so closely that recommended conversion coefficients can be used. The existence of only a small difference in the spectral distribution of the "matched reference field" compared to the nominal reference field is validated by procedures, which are given and described in detail in this document. For matched reference radiation fields, recommended conversion coefficients are given in ISO 4037-3 only for specified distances between source and dosemeter, e.g., 1,0 m and 2,5 m. For other distances, the user has to decide if these conversion coefficients can be used.The second method is to produce "characterized reference fields". Either this is done by determining the conversion coefficients using spectrometry, or the required value is measured directly using secondary standard dosimeters. This method applies to any radiation quality, for any measuring quantity and, if applicable, for any phantom and angle of radiation incidence. The conversion coefficients can be determined for any distance, provided the air kerma rate is not below 1 μGy/h.Both methods require charged particle equilibrium for the reference field. However this is not always established in the workplace field for which the dosemeter shall be calibrated. This is especially true at photon energies without inherent charged particle equilibrium at the reference depth d, which depends on the actual combination of energy and reference depth d. Electrons of energies above 65 keV, 0,75 MeV and 2,1 MeV can just penetrate 0,07 mm, 3 mm and 10 mm of ICRU tissue, respectively, and the radiation qualities with photon energies above these values are considered as radiation qualities without inherent charged particle equilibrium for the quantities defined at these depths.This document is not applicable for the dosimetry of pulsed reference fields.

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