核能

[中文适用范围]： 本文件规定了放射源产生的参考β辐射场的要求，用于校准个人和区域剂量计和剂量率计，用于确定Hp(0,07)、H'(0,07;Ω)、Hp(3)和H'(3;Ω)的量，并确定它们作为β粒子能量和入射角函数的响应。β剂量测定中的基本量是组织等效平板模型中的吸收剂量率。本文件给出了用于产生参考β辐射场的放射性核素的特性，给出了合适的源结构示例，并描述了在国际辐射单位和测量委员会(ICRU)球体中测量0.07毫米深度处残余最大β粒子能量和剂量当量率的方法。所涉及的能量范围介于 0.22 MeV 和 3.6 MeV 之间，最大 β 能量对应于 0.07 MeV 至 1.2 MeV 的平均 β 能量，剂量当量率范围从大约 10 µSv·h-1 到至少 10 1 Sv h · 。 − 此外，对于某些源，给出了剂量当量率随入射角的变化。但是，如 ICRU 56[5] 所述，用于区域监测的环境剂量当量 H*(10) 和用于个人监测的个人剂量当量 Hp(10) 对于任何 β 辐射来说都不是适当的量，即使是穿透 10 毫米组织的辐射（Emax > 2 MeV）。本文件适用于两个系列的参考 β 辐射场，可从中选择确定仪器特性（校准以及响应的能量和角度依赖性）所需的辐射。系列 1 参考辐射场由放射源产生，这些放射源与束平坦化滤光片配合使用，旨在在指定距离的大面积区域内产生均匀的剂量当量率。拟议的 106Ru/106Rh、90Sr/90Y、85Kr、204Tl 和 147Pm 源产生的最大剂量当量率约为 200 mSv·h–1。系列 2 参考辐射场是在不使用束平坦化滤光片的情况下产生的，这允许使用大面积平面源和一系列源到校准平面的距离。靠近源的地方，只会产生相对较小的均匀剂量率区域，但该系列的优势在于将能量和剂量率范围扩展到系列 1 之外。该系列还包括使用聚甲基丙烯酸甲酯 (PMMA) 吸收剂来降低最大β粒子能量的辐射场。使用的放射性核素是系列 1 的放射性核素；这些源产生的剂量当量率高达 10 Sv·h–1。 [外文原描述]： This document specifies the requirements for reference beta radiation fields produced by radioactive sources to be used for the calibration of personal and area dosemeters and dose-rate meters to be used for the determination of the quantities H p (0,07), H' (0,07; Ω ), H p (3) and H' (3; Ω ), and for the determination of their response as a function of beta particle energy and angle of incidence. The basic quantity in beta dosimetry is the absorbed-dose rate in a tissue-equivalent slab phantom. This document gives the characteristics of radionuclides that have been used to produce reference beta radiation fields, gives examples of suitable source constructions and describes methods for the measurement of the residual maximum beta particle energy and the dose equivalent rate at a depth of 0,07 mm in the International Commission on Radiation Units and Measurements (ICRU) sphere. The energy range involved lies between 0,22 MeV and 3,6 MeV maximum beta energy corresponding to 0,07 MeV to 1,2 MeV mean beta energy and the dose equivalent rates are in the range from about 10 µSv·h -1 to at least 10 Sv·h -1. . In addition, for some sources, variations of the dose equivalent rate as a function of the angle of incidence are given. However, as noted in ICRU 56 [ 5 ] , the ambient dose equivalent, H *(10), used for area monitoring, and the personal dose equivalent, H p (10), as used for individual monitoring, of strongly penetrating radiation, are not appropriate quantities for any beta radiation, even that which penetrates 10 mm of tissue ( E max > 2 MeV). This document is applicable to two series of reference beta radiation fields, from which the radiation necessary for determining the characteristics (calibration and energy and angular dependence of response) of an instrument can be selected. Series 1 reference radiation fields are produced by radioactive sources used with beam-flattening filters designed to give uniform dose equivalent rates over a large area at a specified distance. The proposed sources of 106 Ru/ 106 Rh, 90 Sr/ 90 Y, 85 Kr, 204 Tl and 147 Pm produce maximum dose equivalent rates of approximately 200 mSv·h –1 . Series 2 reference radiation fields are produced without the use of beam-flattening filters, which allows large area planar sources and a range of source-to-calibration plane distances to be used. Close to the sources, only relatively small areas of uniform dose rate are produced, but this series has the advantage of extending the energy and dose rate ranges beyond those of series 1. The series also include radiation fields using polymethylmethacrylate (PMMA) absorbers to reduce the maximum beta particle energy. The radionuclides used are those of series 1; these sources produce dose equivalent rates of up to 10 Sv·h –1 .