中子场及γ射线自吸收在PGNAA测量中的影响研究

Study of Influence of Neutron Field and γ-ray Self-absorption on PGNAA Measurement

摘要: 在中子活化瞬发γ射线分析（PGNAA）技术测量中，被测样品内部中子场分布及γ射线自吸收对测量结果有一定影响。针对一套水溶液样品中有害元素的检测装置，通过对两种效应统一考虑并进行了理论计算，建立了一套相应的理论修正模型，并将其应用于检测装置的蒙特卡罗模拟计算结果中。结果表明，经该理论模型修正后，样品中中子场分布及γ射线自吸收对分析结果所造成的影响得到了显著改善。

Abstract: In PGNAA measurement, the distributions of neutron field and γ-ray self-absorption in samples have an influence on the measurement results. A corresponding correction model with two effects into consideration and a theoretical calculation were carried out with an aqueous solution element detection setup. The theoretical calculation was applied to measurement results of detecting device by Monte Carlo simulation. After modification on the theoretical model, the results show that influence of neutron field and γ-ray self-absorption on PGNAA measurement decreases.