脉冲快热中子分析探雷系统的源中子慢化技术研究  

Neutron Source Moderation Technique for PFTNA Landmine Detection

作　　者：丁阁[1] 郝樊华[1] 储诚胜[1] 曾军[1] 向清沛[1] 雷家荣[1] 胡广春[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《核电子学与探测技术》2014年第1期45-50,共6页Nuclear Electronics & Detection Technology

摘　　要：脉冲快热中子分析(PFTNA)是一种先进的可对块状物品进行成份分析的无损检测技术,它在探雷中扮演着最终决策的重要角色,但对N元素的探测速度过慢一直是该技术的短板。在PFTNA探雷实验中,为了提升对可疑目标物中N元素的探测速度,采用MCNP5程序为脉冲D-T中子发生器设计了全新的石墨慢化体。模拟计算结果表明,该石墨慢化体的引入可以有效提高脉冲滞空内目标物中慢、热中子注量,从而较大程度地提升对N元素的探测速度。开展了该慢化体慢化效能的验证实验,实验结果与理论计算符合良好,表明中子源石墨慢化体的引入,能明显提升PFTNA探雷系统对N元素的探测速度。Pulsed fast/thermal neutron analysis （ PFTNA） is an advanced bulk technique for non -destructive elemental characterization , which plays an important role of confirmation sensor in demining activities , but it has a drawback in the detection speed of nitrogen .For improving the detection speed of nitrogen in the object under interrogation in PFTNA landmine identification experiment , a brand new graphite moderator designed u-sing Mont-Carlo method was introduced to the pulsed D -T neutron generator .The simulation results indica-ted that the adoption of the moderator can largely increase the thermal -neutron flux between pulses , and then increase the detection speed of nitrogen .The theoretical enhancements brought by the moderator was validated by relevant experiment , and the verification data tallied well with the simulation result , which demonstrated the adoption of graphite moderator can largely improve the detection speed of nitrogen in PFTNA countermine exper -iment .

关 键 词：脉冲快热中子分析 地雷探测 中子慢化 蒙卡模拟 

分 类 号：O571.53[理学—粒子物理与原子核物理]