期刊论文

Study of Neutron Shield and Absorber for Gamma Total Absorption Facility

中文

原子核物理评论

1007-4627

2020

37

03

771-776

10.11804/NuclPhysRev.37.2019CNPC30

11605294:国家自然科学基金 11675268:国家自然科学基金 11790321:国家自然科学基金 11975317:国家自然科学基金

本校为第一机构

中国原子能科学研究院已经建造完成了我国第一套全吸收型BaF2探测装置,采用瞬发γ测量法,精确测量中子俘获反应截面。中子源是利用HI-13串列加速器产生的脉冲化质子束,通过^(7)Li(p,n)^(7)Be反应建立。为了有效降低周围环境材料和探测器产生的散射中子本底,约束中子束流的形状,使用MCNP程序模拟设计了屏蔽体,采用含硼聚乙烯(B_(4)C质量分数为5%)包裹5 cm铅的方案,以及准直器采用平行孔的方案。该设计使样品处的中子束斑平整均匀,直径约为2 cm,束斑外的中子注量降低5个数量级,γ注量降低3个数量级。同时设计了中子吸收体(外半径为10 cm,厚度为^(7)cm)用于吸收待测样品产生的散射中子。MCNP和GEAN...

The first gamma total absorption facility (GTAF) in China has been constructed in China Institute of Atomic Energy, which will be used to accurately measure the neutron capture cross section by prompt gamma method. A neutron source is established by 7Li(p, n)7Be reaction using pulsed proton beams generated by HI-13 tandem accelerator of CIAE. In order to effectively reduce the scattering neutron background produced by surrounding materials and detectors, and restrain the shape of neutron beam, neutron shield with boron-containing polyethylene (5% of B_4C) coated with 5 cm lead and collimator o...