摘要
氘氘(D-D)中子发生器具有中子产额高,单色性好,可小型化等优势,因而在中子技术应用领域有着广阔的应用前景.D-D中子发生器产生的2.5 MeV中子由于穿透能力强以及穿过屏蔽层时产生二次γ射线因而难以屏蔽.本课题旨在设计一个符合国家相关规定的D-D中子发生器辐射防护方案.用蒙特卡罗程序模拟2.5 MeV中子以1×10^(8)n·s^(-1)通量穿过400 mm混凝土屏蔽墙时,工作人员所在监督区中子的最大周围剂量当量率为5.26μSv·h^(-1),高于职业暴露剂量限值.在此基础上,选用含硼高密度聚乙烯材料进行屏蔽加固.蒙特卡罗模拟结果表明,屏蔽加固后监督区中子的最大周围剂量当量率为0.49μSv·h^(-1),低于职业暴露剂量限值,其余各区域中子的周围剂量当量率也低于设计时要求的安全标准.实验测量结果与蒙特卡罗模拟结果基本一致.本文的研究结果为同类型D-D中子发生器的辐射防护提供了参考和借鉴.
The deuterium-deuterium(D-D)neutron generator is a common neutron source for fast neutron activation analysis.It has broad application prospects in the field of neutron technology applications,such as neutron photography,neutron activation analysis,explosives and drug detection,etc.This study aims to design a radiation protection scheme for D-D neutron generator which complies with relevant national regulations.Based on Monte Carlo method,the simulation obtains the highest neutron ambient dose equivalent rate in the remaining regions except the control region.The Monte Carlo simulation results indicate that after adding a shielding layer of boron-containing high-density polyethylene with a maximum thickness of 22.4 cm on the foundation of a 400 mm concrete building wall,the highest neutron ambient dose equivalent rate in the supervision area is 0.49μSv·h^(-1),which is lower than the occupational exposure dose limit.Moreover,the neutron ambient dose equivalent rate in the remaining regions is also lower than the safety standard required at the time of design.The experimental results are basically consistent with the results of the MCNP6 simulations.The results of this study provide a reference for the radiation protection of the D-D neutron generator.
作者
徐浩博
张天浩
吕会议
袁长迎
XU Hao-Bo;ZHANG Tian-Hao;L Hui-Yi;YUAN Chang-Ying(School of National Defence Science&Technology,Southwest University of Science and Technology,Mianyang 621000,China)
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第4期120-127,共8页
Journal of Sichuan University(Natural Science Edition)
作者简介
徐浩博(1995-),男,四川雅安人,硕士研究生,研究领域为中子辐射防护与中子活化分析;通讯作者:吕会议.E-mail:huiyilv@163.com。
