基于CR39固体核径迹探测器的低能中子剂量测量方法初步研究

Study on dosimetric method of low energy neutron with CR39 solid state nuclear track detector

本文给出了一种采用固体核径迹探测器测量低能(0.5 e V以下能量)中子的双片径迹计数方法,利用蒙特卡罗模拟和实验,统计分析了低能中子引起的探测器单位面积径迹密度。结果显示,采用双片径迹计数方法,实现了CR39对于低能中子的响应,可以对低能中子引起的个人剂量进行估算。应用在中子职业个人剂量监测时,有效甄别了背景径迹的影响,因而降低了测量误差,对减小中子个人剂量监测的测量不确定度也是一个可行的方法。

A dual-track counting method and a detector structure for measuring low energy neutrons （energy below 0.5 eV） with a solid state nuclear track detector are described. The detector track density per unit area induced by low energy neutron was analyzed by both Monte Carlo simulation and field experiments. The results showed that the dual-track counting method achieved the response of CR39 to low energy neutrons, suggesting that individual dose induced by low energy neutron could be estimated with this method. The energy response range of CR39 was extended so that low energy neutrons with fluence of less than 104 could be measured. The dual-track counting method can effectively discriminate the background track for monitoring of personal neutron dose, thus the measurement uncertainty is reduced.