基于3层硅探测器的主动式中子个人剂量计研制

Neutron Personal Dosimeter Based on Three Silicon Detectors

研制了一种具有能量分辨能力的中子个人剂量计。该个人剂量计由3层硅探测器组成,硅探测器周围装有6 LiF、聚乙烯和含硼聚乙烯作为转化体、慢化体和吸收体。个人剂量计有直读和解谱两种工作模式。直读模式将中子能区划分为低能、中能和快中子3个能区,可实时测量。解谱模式可获得快中子能区的中子能量分布。利用GEANT4程序模拟了7MeVγ射线的能量沉积谱,设置适当的甄别域以降低γ射线的影响。采用GEANT4程序模拟了个人剂量计对不同能量入射中子的个人剂量当量率响应。在加速器单能中子参考辐射场中完成了单能中子剂量响应的实验校准,对模拟计算的响应函数进行了实验修正,并得出了不同能区的平均中子个人剂量当量率响应。

A neutron personal dosimeter with energy resolution ability was developed.It consists of three silicon detectors,which are covered by 6LiF,polythene and boron plastic.This personal dosimeter has two calculation modes which are real-time mode and unfolding mode.Real-time mode divides the whole neutron energy range into three parts:Low energy,intermediate energy and fast neutron energy.Unfolding mode can deduce the fast neutron spectra.GEANT4 program was used to simulate the pulse height spectra of 7 MeV gamma ray,and the contribution to personal dose equivalent caused by gamma ray was subtracted.GEANT4 program was used to calculate the neutron personal dose equivalent response matrix of different energy.The personal dose equivalent response experiments were done in monoenergetic neutron field to calibrate the simulation,and deduce the real personal dose equivalent response matrix.