光纤 第 1-54 部分：测量方法和测试程序 伽马辐照（3.0 版）

[中文适用范围]： “本文件概述了一种测量暴露于伽马辐射的光纤和光缆的稳态响应的方法。它可用于确定 B 类单模或 A 类@ A1 类和A2 多模光纤@由于暴露于伽马辐射而呈成缆或非成缆形式@。当暴露于伽马辐射时，成缆和非成缆光纤的衰减通常会增加。这主要是由于在缺陷位置捕获了辐射解电子和空穴玻璃中的辐射（即“色心”的形成）。该测试程序侧重于两个感兴趣的范围：适合估计环境背景辐射@影响的低剂量率范围和适合估计的高剂量率范围环境背景辐射影响的测试是通过类似于 IEC 60793-1-40 方法 A@ cut-back 的衰减测量方法来实现的。通过监测测试样品暴露于伽马辐射之前、期间和之后的功率来测试不利核环境的影响。光（光漂白）或热引起的色心减少会导致恢复（减少辐射引起的衰减）。恢复可以在很宽的时间内发生，这取决于辐照时间和退火温度。这使得辐射引起的衰减的表征变得复杂，因为衰减取决于许多变量，包括测试环境的温度@样品的配置@总剂量和应用于样品的剂量率以及用于测量它的光水平。该测试不是针对光缆非光学材料组件的材料测试。如果研究暴露在辐射下的电缆材料的降解，将使用其他测试方法。该测试方法的编写包含清晰的简洁指令列表。 IEC TR 62283 中单独介绍了执行正确@相关且富有表现力的辐照测试以及限制测量不确定度所需的背景知识。” [外文原描述]： IEC 60793-1-54:2018 outlines a method for measuring the steady state response of optical fibres and optical cables exposed to gamma radiation. It can be employed to determine the level of radiation-induced attenuation produced in Class B single-mode or Class A, category A1 and A2 multimode optical fibres, in either cabled or uncabled form, due to exposure to gamma radiation. The attenuation of cabled and uncabled optical fibres generally increases when exposed to gamma radiation. This is primarily due to the trapping of radiolytic electrons and holes at defect sites in the glass (i.e. the formation of "colour centres"). This test procedure focuses on two regimes of interest: the low dose rate regime suitable for estimating the effect of environmental background radiation, and the high dose rate regime suitable for estimating the effect of adverse nuclear environments. The testing of the effects of environmental background radiation is achieved with an attenuation measurement approach similar to IEC 60793-1-40 method A, cut-back. The effects of adverse nuclear environments are tested by monitoring the power before, during and after exposure of the test sample to gamma radiation. The depopulation of colour centres by light (photo bleaching) or by heat causes recovery (lessening of radiation induced attenuation). Recovery can occur over a wide range of time which depends on the irradiation time and annealing temperature. This complicates the characterization of radiation induced attenuation since the attenuation depends on many variables including the temperature of the test environment, the configuration of the sample, the total dose and the dose rate applied to the sample and the light level used to measure it. This test is not a material test for the non-optical material components of a fibre optic cable. If degradation of cable materials exposed to irradiation is studied, other test methods will be used. This test method is written to contain a clear, concise listing of instructions. The background knowledge that is necessary to perform correct, relevant and expressive irradiation tests as well as to limit measurement uncertainty is presented separately in IEC TR 62283. This third edition cancels and replaces the second edition published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - test conditions related to photobleaching have been changed; - the test length has been modified to yield a total induced attenuation in the test sample at the end of the irradiation between 3 dB and 10 dB.