国产Am-Be中子源4.438 MeV γ射线与中子强度比值测量  

Measurement of 4.438 MeV γ-ray to Neutron Intensity Ratio for Am-Be Neutron Source

作　　者：刘镇洲[1] 陈金象[1] 朱培[1] 李永明[1] 张国辉[1] 

机构地区：[1]北京大学物理学院重离子物理教育部重点实验室,北京100871

出　　处：《原子能科学技术》2008年第4期300-304,共5页Atomic Energy Science and Technology

摘　　要：本工作涉及准确测量国产Am-Be中子源发射的4.438 MeV γ射线与中子强度比值R=Sγ/Sn的实验方法。中子源的中子发射率用锰浴法进行比对测量。用75 mm×75 mm NaI(Tl)探测器测量中子源的γ能谱;用MCNP程序模拟计算中子引起的γ本底和探头的源峰探测效率。实验与理论计算得到的R值符合得很好。综合评价已发表的R实验值,给出了R推荐值为0.575(1±4.8%)。结果表明,R值可认为是Am-Be源的一标志性特征量。The present research concerns in the accurate measurement of the 4. 438 MeV γ-ray to total neutron intensity ratio, namely R=Sr/Sn, for homemade Am-Be neutron source. The neutron strength of the source relative to a previously standardized source was determined by the manganese bath technique. The y-ray spectra of the source were measured using a φ75mm×75 mm NaI（T1） detector. The background induced by neu- trons and the absolute full energy peak efficiency of the detector were calculated using the MCNP code. The experimental ratio obtained agrees well with the calculated value. A synthetic evaluated and recommended value of R=0.575（1±4.8%） was given. The experimental R value appears an important characteristic for the Am-Be source.

关 键 词：Am-Be中子源 4.438 MeVγ射线 中子发射率 MCNP程序 

分 类 号：O571.32[理学—粒子物理与原子核物理]