【作者】 胡青元； 李波均； 张德； 郭洪生； 杨高照； 司粉妮； 刘建；

【Author】 HU Qing-yuan, LI Bo-jun, ZHANG De, GUO Hong-sheng, YANG Gao-zhao, SI Fen-ni, LIU jian (Institue of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China)

【机构】 中国工程物理研究院核物理与化学研究所；

【摘要】 用MCNP蒙特卡罗程序建立计算模型,研究了聚乙烯慢化体结构对BF3长中子计数器的中子探测效率的影响。使用九根正比计数管阵列,通过模拟调整慢化体结构,使探测器在2MeV～14MeV范围内能响一致,且具有比较高的灵敏度。根据模拟结果建立了探测器。利用Am-Be中子源及加速器DD,DT中子源对探测器的能量响应进行了测量,得到了比较一致的探测效率,从实验上验证了模拟模型的可靠性。实验标定长计数器在1m处的探测效率约为1.5×10-4,是同类探测器Hanson长计数器的15倍。更多还原

【Abstract】 The efficiency of a long counter with boron trifluoride proportional tubes imbedded in a polyethylene moderator was simulated by a Monte Carlo program, MCNP(Monte Carlo N-Particle Code). Nine tubes are involved in the detector. A moderator structure with which the counter has a uniform and high sensitivity for neutrons from 2MeV to 14MeV was achieved by simulation. According to calculated results the counter was built. Its efficiencies were calibrated on an Am-Be source and a accelerator which served as DD and DT neutron sources. The experimental neutron efficiencies of the three kinds of sources are approximately uniform. Validity of the simulated model is proved by the consistent results between calculation and experimental data. Measured efficiency from experiment is 1.5×10-4 at a distance of 1m, which is 15 times of the similar detector, the Hanson long counter.更多还原