放射防护 - 参考脉冲辐射的特性 - 第1部分:光子辐射

[中文适用范围]： 本文件直接适用于脉冲持续时间从0.1毫秒到10秒的脉冲X辐射。该范围涵盖了发布时医学诊断中使用的整个范围。某些规范也适用于更短的脉冲；一个例子是单脉冲的空气比释动能。这样的脉冲例如可以由X射线闪光装置或高强度飞秒激光器产生。其他规范不适用于更短的脉冲；一个例子是空气比释动能率的时间相关行为。由于技术原因，如果没有合适的仪器（例如，对于飞秒激光器产生的脉冲），则无法测量。本文件规定了用于校准和测试辐射防护剂量计和剂量率仪对脉冲辐射响应的参考脉冲辐射的特性。目前，它仅涉及单脉冲的特性。单脉冲是剂量计最难测量的。测量重复脉冲的剂量更容易，但仍比连续辐射更困难，即剂量计在测量重复脉冲时的性能介于这两个极端之间。辐射特性包括以下内容：a) 脉冲空气比释动能率的时间相关行为；b) X射线管高压在脉冲期间的时间相关行为；c) 辐射束横截面积内空气比释动能率的均匀性；d) 一个辐射脉冲的空气比释动能；e) 辐射脉冲的空气比释动能率；f) 重复频率。本文件不定义新的辐射品质，而是使用现有ISO和IEC标准中规定的辐射品质。相反，本文件给出了脉冲辐射参数与规定辐射品质的连续辐射参数之间的联系。它不规定脉冲辐射场的特定值或系列值，而是仅规定校准剂量计和剂量率仪以及确定其响应所需的相关脉冲辐射参数的限制。脉冲参数与模体相关量之间的关系使用根据ISO 4037（所有部分）的转换系数确定。这是可能的，因为使用了现有ISO和IEC标准中规定的辐射品质。给定的参考脉冲X射线装置的特征在于根据本文件满足全部规范和要求的参数范围。因此，并非所有参考脉冲X射线装置都能产生覆盖相同参数范围的脉冲。 [外文原描述]： This document is directly applicable to pulsed X-radiation with pulse duration of 0,1 ms up to 10 s. This range covers the whole range used in medical diagnostics at the time of publication. Some specifications can also be applicable for much shorter pulses; one example is the air kerma of one pulse. Such a pulse can be produced, e.g. by X-ray flash units or high-intensity femtosecond-lasers. Other specifications are not applicable for much shorter pulses; one example is the time-dependent behaviour of the air kerma rate. This cannot be measurable for technical reasons as no suitable instrument is available, e.g. for pulses produced by a femtosecond-laser. This document specifies the characteristics of reference pulsed radiation for calibrating and testing radiation protection dosemeters and dose rate meters with respect to their response to pulsed radiation. At this point, it is only concerned with the characteristics of single pulses. Single pulses are the most difficult for dosemeters to measure. Determining the dose for repeated pulses is easier, but still more difficult than for continuous radiation, i.e. the performance of the dosemeters when measuring repeated pulses lies between these extremes. The radiation characteristics includes the following: time-dependent behaviour of the air kerma rate of the pulse; time-dependent behaviour of the X-ray tube high voltage during the pulse; uniformity of the air kerma rate within a cross-sectional area of the radiation beam; air kerma of one radiation pulse; air kerma rate of the radiation pulse; repetition frequency. This document does not define new radiation qualities but uses those radiation qualities specified in existing ISO and IEC standards. Instead, this document gives the link between the parameters for pulsed radiation and the parameters for continuous radiation specifying the radiation qualities. It does not specify specific values or series of values for the pulsed radiation field but specifies only those limits for the relevant pulsed radiation parameters that are required for calibrating dosemeters and dose rate meters and for determining their response depending on the said parameters. The pulse parameters with respect to the phantom-related quantities were determined using conversion coefficients according to ISO 4037 (all parts). This is possible as the radiation qualities specified in existing ISO and IEC standards are used. A given reference pulsed X-ray facility is characterized by the parameter ranges over which the full specifications and requirements according to this document are met. Therefore, not all reference pulsed X-ray facilities can produce pulses covering the same parameter ranges.