【摘要】 针对γ射线剂量增大时,大面积塑料闪烁探测器剂量线性会变差这一问题,采用能谱测量方式对塑料闪烁探测器的剂量线性进行修正。首先在单能辐射场中,探测器通过能谱测量电路在上位机形成辐射场能谱,然后按照能量线性规律算出每道址的权重因子,以标准剂量仪所测剂量率为参考值得到修正公式,接下来对待测辐射场进行能谱采样,根据每道计数和修正公式,得到修正后的总计数率和剂量率,从而对塑料闪烁探测器的剂量线性进行修正。结果表明:经过修正以后,在137Cs辐射场中剂量测量最大相对误差由-24.32%变为-6.90%,在60Co辐射场中最大相对误差由-72.22%变为-27.78%。可以看出,经过修正的探测器剂量线性得到很大改善,可为辐射场中γ射线剂量的准确测量提供技术参考。更多还原

【Abstract】 As the dose linearity of large-area plastic scintillation detectors will become worse with the increase of the γ-ray dose, the energy spectrum measurement is thus introduced to solve this problem. First, the detector used the energy spectrum measurement circuit to form radiation field energy spectrum on the upper computer in a single-energy radiation field. Then, the weight factor of each channel was calculated according to the linear rule of the energy. A correction formula was hence acquired on the basis of the reference value, namely the dose rate measured by a standard dosimeter. Next, the energy spectrum was sampled in the to-be-measured radiation field.The dose linearity of the plastic scintillation detectors were modified with the gross count rate and the dose rate that had been corrected in accordance with the count in every channel and the correction formula. The correction results have proved that the maximum relative error measured changes from-24.32% to-6.90% in the137 Cs radiation field and from-72.22% to-27.78% in the60 Co radiation field. It can be perceived that, the detector dose linearity has been greatly improved after correction, which has provided a technical reference for accurately measuring theγ-ray dose in radiation fields.更多还原