γ透射法测管道油垢厚度响应的宽束影响

Broad-beam Influence on the Response of Measuring Pipeline Grease Stain Thickness by γ-ray Transmission Method

对利用γ射线透射幅度谱测管道油垢厚度响应的宽束影响进行了研究。模拟实验装置由137Cs γ射线的准直束、NaI(TI)探测器和BH1224多道谱仪组成。实验结果表明:响应与油垢厚度呈线性关系。利用光电峰区测垢,标定直线的斜率为负值;利用康普顿峰区测垢受宽束的影响,其标定直线的斜率为正值,但随管道直径增大斜率迅速减小。利用全谱测垢,对于细管道斜率为正值,对于粗管道则为负值。实测的修正因子β与1的偏差均<2％。

The study on the broad-beam influence of the grease stain thick response using the amplitude spectrum of the transmitted γ- ray is reported. The simulated experimental device consists of a collimating beam of 137Cs γ- ray, a NaI(Tl) scintillation detector and a BH1224 multi-channel spectrometer. The experiment results indicate that there is a linear relation between the response and the grease stain thickness. When the measuring grease stain thickness response, the slope of the calibration line is negative with the photoelectric peck spectrum zone; with the Compton spectrum zone as a result of broad-bean, the slope is positive, but its slope value is rapidly reduced when the pipeline diameter is increased; with the total spectrum zone, its slope is positive for the thin pipeline, but its slope is negative for the wide pipeline. The error between the measured correction factor β to 1 is all less than 2%.