脉冲X射线剂量率测量不确定度分析

“强光一号”短脉冲高能X射线剂量率测量，主要包括脉冲射线总剂量与脉冲射线时间宽度的测量，前者采用热释光剂量计测量，后者采用PIN半导体探测器记录。根据不确定度传递数学模型，分析了影响X射线剂量和脉冲宽度测量结果的因素。针对“强光一号”短脉冲高能X射线测量，定量地给出了各种因素引入的测量不确定度，总剂量测量是影响剂量率测量准确性的决定性因素，其相对标准不确定度为25.1％，脉冲宽度测量不确定度为3.7％，剂量率测量扩展不确定度为50.8%，置信概率95%。

Analysis of measurement uncertainty of X-ray dose rate

The measurement of short pulse X-ray of high energy produced by Qiangguang Ⅰ accelerator for radiation effect study includes X-ray dose and pulse duration measuring. The thermoluminescence dosemeter (TLD) is used to measure X-ray dose, and the PIN semiconductor detector is employed for recording waveforms of X-ray. The dose rate is calculated out by the results of X-ray dose and pulse duration. By the mathematic model of uncertainty, factors with important effect on X-ray measuring are analyzed. For the measurement uncertainty of X-ray pulse duration is 3.7%, the measuring of X-ray dose with relative standard uncertainty of 25.1% plays a crucial role in determining X-ray dose rate, and the expanded uncertainty of dose rate is about 50.8% with confidence probability of 95%．